|
RIGS_ID |
Grid_reference |
Locality |
Feature |
Stratigraphy |
Geomorphology |
Description |
Access |
RIGS |
InterestCategory |
|
0006 |
SO 396 876 |
Hillend Quarry / Hillend Farm (W) - Lydbury North. |
Track/roadside |
Silurian: Llandovery Series (Lower): Pentamerus Beds. |
This site below the steep S end of the Longmynd and just above the
meandering River Onny. |
This site consists of a lot of fine talus and
some larger pieces (up to 50 mm across) which are still revealing a lot of
fossils and which are from the Pentamerus Beds. To the right of the exposure
there is some interesting weathering of iron-rich rocks. The disused
excavations behind the fence do not appear to show any more exposures of
rock as they are all grassed over and this is private land. |
This is a road side site so access is no problem. Park by the gate to the E
in dry weather or in the lay-by about 600m SW where there is space for a few
cars without any danger of blocking access. The exposure is clearly seen on
the N side of the road. |
RIGS Yes. This site is an SSSI and a RIGS. It is an easily accessible site
showing a clearly identifiable lithology and has plenty of loose material to
study. As it is still revealing fossils and is still accessible it should
remain as a RIGS. It was designated as a RIGS to help ensure a continuance
of its role as a good introductory locality as well as exposing a component
of the Silurian section along the A489 between Hillend and the Cwm Head
road. |
Sedimentology/Stratigraphy |
|
0007 |
SO 425 854 |
Onny River Section |
Cliff |
Unconformity between Ordovician (Caradoc: Onny Shales) and Silurian (Upper
Llandovery: Hughley Shales) |
River cliff of meandering Onny River. |
This is the classic Ordovician-Silurian unconformity. It can be detected in
the cliff on the N bank by a subtle change of dip from 22°SE to 18°SE with
the Hughly Shales overlapping the Onny Shales. This site remains quite clear
of vegetation and access and viewing is easy. It is not possible to cross
the river except at very low flows. This is good as it means the faces are
less likely to be hammered. Continued erosion by the river at times of high
flows will remove some material but this should keep the face 'clean'.
Trilobites are sometimes found in the river at low flows. There is a lot of
loose material in the form of river worn pebbles of various ages that have
been brought down-stream. The SSSI covers the river and its banks from
426852 to 422854. This area includes outcrops which are the type-sections of
the Actonian and Onnian Stages of the Ordovician (ref.1). It is unclear
where the Actonian stage finishes and that of the Onnian starts and this
junction may only be visible in the river bed at times of low flow. |
This is found along the Onny Valley walk which is a permissive footpath
allowed by the owners of Cheney Longville Estate. The trial runs from a car
park over the railway bridge off the A49 up the Cheney Longville road. It
continues along the river and old railway as far as Glenburrell. |
RIGS Yes. This is an SSSI for its geological importance therefore it ought
to be designated as a RIGS. It should be designated as part of a larger site
encompassing the whole of the river as outlined in the attached note (Word
file name:- Onny Valley Area). |
Sedimentology/Stratigraphy |
|
0011 |
SO 519 897 to SO 521 893 |
Upper Millichope - Munslow |
Stream/brook |
Silurian: Lower Ludlow: Lower and Middle Elton Formation (ref.1). |
This site is on the NW slope of the NE/SW trending valley of the River Corve.
The other side of this valley is partly made up of the Brown Clee Hills.
The stream eventually runs into the River Corve. |
The reason for notification as an SSSI is as follows: This site shows a
long stratigraphical section through the Lower Ludlow Lower and Middle Elton
Formation with a Lobograptus scanicus graptolite fauna and an acritarch
microflora typical of the Tylotopalla pyramidale biozone. The fauna and
flora suggest deposition of the calcareous siltstones here in comparatively
deep water conditions. The macrofauna present consists of well-preserved
graptolites trilobites and brachiopods. There are outcrops in the banks of
the stream at intervals for several hundred meters up the stream from the
bridge by the footpath (see below). These are continually eroding so provide
a plentiful supply of loose material in which to find the fossils mentioned.
The trilobites are the most obvious and there are still lots of specimens to
be found in various states of preservation. As usual they are dislocated
and there appear to be far more pygidia than cephalons. Some separated
compound eyes can also be found. Because of the abundant material there is
NO NEED TO HAMMER at the exposures. More material can be found under the
rotting leaves. Other fossils found on this visit included gastropods (Loxonema)
the occasional graptolite small brachiopods and bivalves as well as the
Dalmanites trilobites. The best fossil collecting exposures appeared to be
between the first two bridges. This is the most accessible part of the
stream and the rock appeared to be more fossiliferous here. Above the next
bridge upstream the stream has created more of a gorge which was impassable
at the level of flow on this visit. Because of the steepness of the banks it
is also difficult to reach the stream level from the road at most places
above this bridge. There are a few places where access is possible but
these are quite limited and the rock at the higher levels did not reveal as
many fossils. The top of the site looses its interest altogether with no
exposures and no 'beaches' on which to find loose material. The rock is
siltstone which gets less green and more calcareous upstream. |
Upper Millichope is on a minor road between the Corve Dale road (B4368) and
Wall under Haywood (on the B4371). It is probably best to traverse the
stream in an upstream direction as the bottom of the site is more
interesting and easier to traverse. Enter the stream just upstream of the
footpath over a bridge opposite a farm entrance. By walking in the stream
it is possible to reach the next bridge upstream with very little problem.
At low flow it may be possible to follow the stream further. |
RIGS Yes. This is also an SSSI. It has obvious fossils in abundant loose
material which are suitable for use by all groups of all abilities and
interests. It would be suitable for school groups or researchers. The site
is quite open and easily accessible. |
Fossils |
|
0013 |
SO 426 807 |
View Edge Quarries |
Quarry (disused) |
Silurian: Ludlow Series: Aymestry Group (BGS SO48; Craven Arms). |
These quarries have been cut into the top of a prominent scarp created by
the resistant Aymestry Beds above the softer Lower Ludlow Shales. |
Whilst not as spectacular as the near by site at Brandhill this quarry has very clear features and a greater abundance of
fossiliferous material. This site has remained quite clear with only a few
stunted trees on a few ledges. The faces are mostly very accessible and
whilst some are obscured totally there is still plenty to see. There is
plenty of loose material containing large shell fragments including what
looks like a recently hammered area. The shells are also clearly visible at
certain points within the rock. |
The quarry is accessed via a gate about 200 m SE of Viewedge Farm. Park in
the gateway or elsewhere along the lane. There is no public right of way to
the faces but there is permissive access negotiated by the AONB; large
parties should seek prior permission from the farm at the top of the hill. |
RIGS Yes. This is an SSSI for their distinctive shell banks of the large
strophomonid brachiopod Conchidium knightii. This is a shallow-water fauna
which is characteristic of the Aymestry Limestone Group in this area. |
Fossils |
|
0021 |
SO 602 758 to 603 755 |
Cornbrook Dingle - Coreley |
Stream/brook |
Carboniferous: Cornbrook Sandstone Formation. |
Small stream running down the side of Clee Hill |
There are a number of exposures along this small narrow (<1 m wide) stream
and its steep banks from where it goes under the A4117 to the waterfall
downstream of the track at SO603755. These show very coarse sandstones and
conglomerates which are usually poorly sorted and sub-rounded. The
conglomerates contain mostly quartz clasts but also other lithologies too.
The coarsest conglomerates have quartz clasts of up to 30 mm in the largest
direction. In some beds the conglomerate bands are of various grades; each
one quite well sorted with the intervening rock being medium-coarse
sandstone. Most of the rock has weathered to a rusty orange colour (probaly
from acid minewtaer draining the Coal Measures); this can be variable and
appears as bands in some of the beds. There are areas of calcite
mineralisation seen as thin layers (?slickensides) on some surfaces of the
sandstone. At one point the stream has created a deep gorge which is very
difficult to walk down but can be traversed around the top. A few outcrops
are visible in the gorge below. About 20 m below the track which the stream
goes under there is a series of waterfalls (the site of a former iron
works). These show more rust coloured sandstone. The first of the falls is
the largest with a drop of about 2.5 m (the site of a water wheel) and the
second has a drop of about 1 m. There is an exposure of rock on the E side
of the stream but again this is not accessible due to the steep sides of the
bank. According to ref.1. this site is an SSSI as one of the best exposures
(and the type-locality) of the Cornbrook Sandstone Formation (the lowest
deposit of Pennsylvanian age). It shows how sediments were deposited on St.
George's Land. Good fossil fauna has been found here, especially plants.
Coal mine drainage adit daylights here; iron-stained acid minewater can e
seen discharging on the left bank above the track. |
Park on the A4117 opposite the cottage on the N side of the road. The stream
goes down hill from the corner of the road and can be paddled or followed
most of the way. Alternatively park on the track that leaves the A4117 at
SO608758 where it crosses the stream and follow the stream up the hill.
Other facilities can be found at Clee Hill village 1 km to the west. |
RIGS Yes. This is also an SSSI. Although access is good and there is plenty
of material to work with the streamway itslef is steep and difficult to
follow. The location is the type section for the Cornbrook Sandstone
Formation (some have correlated this with the Carboniferous Millstone Grit)
containing good sedimentary features. An iron smelter was formerly located
here. Coal mine drainage adit daylights here. |
Petrology and Stratigraphy |
|
0022 |
SJ 342 015 to 357 021 |
Hope Valley - Worthen |
Quarry |
Ordovician (Hope Shales) and Silurian (Llandovery Venusbank Formation). |
Quarry; stream and roadside exposures along the bottom of Hope Valley. |
Hope Mill Quarry ( 355021) (as incorporated in the SSSI) used to show Ord/Sil
unconformity. Recent woodland clearance work by the SWT has apparently
destroyed what remained of this outcrop. The quarry still remains and shows
massive sandstones and shales of Llandovery series. These show cross
bedding and bioturbation; with some loose material containing fossils. The
stream bed on the opposite side of the road shows steeply dipping Ordovician
Hope Shales. The stream is accessible in places but without wellies it can
not be walked to see if it reveals a contact with the Silurian at any
point. On the LHS (S) of the quarry there is a spur which descends to the
road. At its base a very small exposure was excavated to see if this was
Hope Shales. It appeared to be dipping east; and was darker than the
obviously Silurian rocks above; but was very broken up. This would need to
be excavated further to see if it was Hope Shales. Also included in this
site is the quarry by the bus stop in Hope village. This shows good folding
of the Silurian rocks. Smaller exposures of folded Silurian rocks can be
seen on the RHS of the road when travelling south. |
The Quarry is situated on the W side of the Bishop's Castle to Shrewsbury
road just N of the village of Hope. It is best to park in SWT carpark or
small lay-by; then walk down the road (N) to the quarry. The road is twisty
and without a footpath; therefore quite dangerous. The stream is
accessible through holes in the hedge in a number of places but its banks
are also often steep. The bus stop site has a lay-by right in-front of it. |
RIGS Yes. Already an SSSI? Should be designated if the unconformity can be
uncovered. Designated for the importance of the unconformity between
Ordovician Hope Shales and the Silurian Venusbank Formation. The Hope
Shales in the Lower Llanvirnian include their type section. Boundary
includes the Hope Valley SSSI. |
Sedimentology/Stratigraphy |
|
0026 |
SJ 375 023 |
Snailbeach Mine |
Mine/adit |
Ordovician: Arenig Series: Mytton Flags (BGS 1: 25000 Shelve Area). |
This site is at the foot of some very steep slopes that lead up onto the
NE/SW trending ridge made by the more resistant Stiperstones Quartzite over
the softer Mytton Flags to the W and Habberley Shales to the E. The view
point on the heritage trail provides excellent views to the N and round to
the SW. |
This was the main mine of the Stiperstones mining district. Small scale
operations continued after the flooding of the lower levels until 1955.
This last mining was for barytes used in the paper and paint industry. The
lower level mining was for barytes; lead and zinc. This site was deemed
unsafe for the local population due to the amount of spoil that was left
from the mining operations. In 1995 a reclamation scheme was completed that
has landscaped most of the spoil tips. There is also a restoration scheme
underway to make safe the remaining buildings and encourage interested
visitors. There is now a heritage trail around the site. This scheme has
included a patch of spoil to be left to be 'picked over' by geologists etc.
This is what is described as the 'Rock Store' on the interpretive panels
that are around the site. This is an area about 20 m in diameter of exposed
spoil. There are still minerals to be found but; as with all these tips;
the most common are calcite; barites and quartz. There is more material
visible in a part of the tip that has remained to make a view point over the
site. However this is likely to be left to become vegetated over time.
This also contains the above minerals but the average size of the loose
material is much smaller. There is no other exposed rock or spoil over the
rest of the site. |
This site is in the village of Snailbeach. There is a car park by the
toilets and village hall that visitors are requested to use. |
RIGS Yes. Spoil has been left for the specific interest of geologists.
Although it is smaller than some of the other tips in the area it is put in
context by the rest of the buildings etc of the heritage trail so a better
understanding can be gained of the importance of the geology to the area and
how it was dealt with. |
Mineralogy/Petrology |
|
0033 |
SO 297 758 |
Black Garn - Chapel Lawn |
Quarry (disused) |
Silurian: Downtonian (Platyschisma beds according to the information on the
Favoured list). |
Quarry on the slopes of the steep side Caer Caradoc which is topped by a
hill fort. |
The LHS of the quarry shows a very impressive distortion due to movement
along a thrust plane. The beds have been clearly distorted into tight
folds. The lower set of these terminates next to the plane of faulting.
The distortion is of massive beds 30 to 120 mm thick with fine laminated
partings of a few cm. The beds appear to be competent and have folded
together. I found no fossils on this visit. The RHS of the quarry is much
more obscured (mainly by moss) but the beds appeared to be unaffected by the
faulting of the LHS. The adjacent stream section is on private land with no
public access. I could not see any exposures of any size within the
stream. There was one small exposure on the upstream side of the road which
showed beds of a few cm thick. As there is no public access it is probably
best to leave these exposures for research use only. |
This site can be found on a small lane that leaves the A488 at Five Turnings
(1.5 km S of New Invention) between Clun and Knighton. The site is on the E
side of the road on a tight bend just E of the entrance to Black Garn Farm.
There is very little parking on the narrow lane but there is a bit of verge
at the point of the site. |
RIGS Yes. This should be a RIGS as a good and easily accessible example of
the effects of faulting / thrusting. The structures are very clear and can
be readily explained. |
Structure |
|
0040 |
SO 317 836 |
Withins Bury Ditches; Clun (Brookbath) |
Track/roadside |
Silurian: Cefn Einion Formation; Platyschisma Beds and Downton Castle
Sandstone (ref.1). |
This track-side cutting is in a small valley on the side of the conical
shaped Sunny Hill from which there are good 360° views interpreted with the
aid of a toposcope. |
This site was described in ref.1 as being a 500 m long section showing the
above horizons with the Downton Bone Bed (equivalent to the Ludlow Bone Bed)
exposed in the banks of a steep ride. I found a good exposure about 2 m by
30 m on the track-side where it bends around a valley. This shows massively
bedded fine; mica rich; sandstone with beds up to 15 m thick. Further down
the track there is an amount of talus but no in situ rock is exposed. It is
possible that this did show rock at the time that the reference was
written. There is more exposure a few metres up the track where a green
way-marked footpath leaves the main track. The making of the footpath has
revealed purple shales which show bioturbation on many of the loose pieces.
One area looked like a badly weathered lump of multiple shell fragments.
Apart from that lump very few fossils were seen. Despite looking quite hard
I could not identify a bed which could have been the bone bed. However the
site is still a good comparison to the more flaggy material of the CEF and
the very shaley flat bedding of the KC beds. In ref.1 fossils to be found
include Cyathaspis banksi; Sclerodus; Onchus and thelodonts. |
Park at the Forestry Commission car park for Bury Ditches and make your way
around the forest tracks. This site is where the green waymarked walk
crosses a hard-cored track. |
RIGS Yes. This should be considered for designation in conjunction with
other sites in the area that show the different facies within the Ludlow
Series and the Lower Devonian (if this site does show Downton Castle
Sandstone). The value of the site would be increased further if the Downton
Bone Bed could be identified. |
Fossils and Sedimentology/Stratigraphy |
|
0043 |
SO 325 956 |
Tasker Quarry - More |
Quarry (disused) |
Ordovician: Llanvirn: Stapeley Volcanics Group and Stapeley Shales. |
Cut into hillside. |
Medium sized quarry showing massive interbedded shales; hard tuffs; breccias
and other pyroclastics. Some small faults. Fauna includes trilobites and
graptolites. (Ref.1.). |
It is now fenced off but there is a stile over it. There is room for one
car to pull of the road in front of the quarry otherwise park in the lane to
Nind just to the south. |
RIGS Yes. Designated to emphasise its geological significance as an
excellent example of sedimentary features which can be preserved within
volcanic sediments. |
Fossils and Sedimentology/Stratigraphy |
|
0045 |
SO 335 990 |
Shelve Farm |
Quarry (disused) |
Ordovician: Arenig Series: Mytton Flags. |
Quarry cut into bank. |
Abundant loose material from the Mytton Flags and the face is easily
accessible. Fossils were found in this material and there is a bentonite
band (ref.1.). Fossils previously found here include trilobites;
graptolites and gastropods. |
The farmer is quite willing to let people get at the site but permission
must be sought first at the house. Access is either through the buildings
or round the top of the farm. Park in the road; or at the farm. |
RIGS Yes. As the SSSI at Shelve Church (337990) is no longer visible this is
a good alternative. This quarry is now behind a relatively new barn and has
possibly been reworked in order to fit this building in. Access is easy and
there is abundant material. It is described on my list as a 'classic
locality'. |
Fossils |
|
0046 |
SO 368 987 |
Stiperstones (main ridge) |
Crag |
Ordovician: Arenig Series: Shelve Group: Stiperstones Quartzite. |
Frost shattered tors on long high NNE/SSW trending ridge formed by resistant
quartzite flanked by less resistant shales. |
This site comprises a series of frost shattered tors with classic 'stone
runs' (associated boulder screes that have formed stone stripes as a result
of solifluction). There are boulders of various sizes and textures from
conglomerate to fine quartzite. Some have quartz veins running through them
occasionally showing well formed quartz crystals. There are good views from
here across to Corndon Hill in the west and down towards Linley in the
south. It is also a very good point a which to look north up the ridge
where other tors can be seen on a good day. |
A footpath climbs to the ridge from the Bog to Linley road from the large
car park at the southeast corner of the area. |
RIGS Yes. The Stiperstones ridge is the best site in the country for stone
runs and displays well the variability of the Stiperstones Quartzite from
fine grained to conglomeratic together with evidence of mineralisation in
the form of quartz veins. |
Geomorphology/Landscape |
|
0047 |
SO 351 964 |
Stiperstones (The Rock) |
Crag |
Ordovician: Arenig Series: Shelve Group: Stiperstones Quartzite. |
Frost shattered tor on long high NNE/SSW trending ridge formed by resistant
quartzite flanked by less resistant shales. |
This is one of a series of frost shattered tors which associated boulder
scree which outcrop on top of the Stiperstones ridge. There are boulders of
various sizes and textures from conglomerate to fine quartzite. Some have
quartz veins running through them; occasionally showing well formed quartz
crystals. There are good views from here across to Corndon Hill in the west
and down towards Linley in the south. It is also a very good point a which
to look north up the ridge where other tors can be seen on a good day. |
A short path leads directly to the rock from the Bog to Linley road. There
is no parking here so it is best to walk down the road from the Nipstone car
park about 1 km to the N. |
RIGS Yes. This should be designated either on its own or as part of a larger
site which incorporated all of the Stiperstones ridge. Designated for its
display of the variability of the Stiperstones Quartzite from fine grained
to conglomeratic and evidence of mineralisation in the form of quartz
veins. The site is also a good view point from which to appreciate the
context of the Stiperstones ridge to the north. |
Geomorphology/Landscape |
|
0048 |
SO 352 764 |
Gripes Nest - Hopton |
Quarry (disused) |
Silurian: Bailey Hill Formation. |
Large quarry cut into the slope of a small valley separating Bedstone Hill
and Hopton Titterhill. |
This is quite a large site about 20 m high and 30 m wide. It is mostly
greenish grey micaceous siltstone but with calcareous nodules and some bands
of finely laminated pale or orange sandstone. There are several slump
features causing folds and changes of dip direction. The overall dip is
about 10°W. The central outcrop shows the slumping well with an obvious
large scale change in dip and folding picked out by light and dark banding.
A large nodule in the exposure to the left and above the central outcrop has
caused deformation of the beds beneath. Uneven laminations could be seen on
a small scale in many of the loose pieces that cover the lower slopes in
many parts. Few fossils were found but there was a lot of bioturbation
evident on the surfaces of the talus and other features such as small
ripples. |
It can be reached from the village of Bedstone either by walking from there
or by following the lane signed to ' Darky Dale' for about 1.4 km than
taking the lane to the R down into the valley. Park opposite the top of
this lane and walk down then follow the unsigned footpath across the stream
(no bridge) and over some fields. The footpath the site is on is connected
to the forestry commission trail of Hopton Titterhill. Parking is therefore
available at the car park for this trail but this is some distance away.
(It is suggested that a copy of the mountain bike trail is obtained for
further reference). |
RIGS Yes. This is a good open site suitable for parties of all sizes. It is
on a footpath so access is easy once the path is located! The slump
features are easily recognized as is the bioturbation. |
Sedimentology/Stratigraphy |
|
0051 |
SO 357 970 |
Stiperstones (Nipstone Rock) |
Crag |
Ordovician: Arenig Series: Shelve Group: Stiperstones Quartzite. |
Frost shattered tor and boulder scree on prominent NNE/SSW trending ridge. |
This tor is separated from the main Stiperstones ridge to the north by a
fault running up the intervening depression (BGS Shelve Inlier map
1:25000). It is now even prominent than before as the Forestry Commission
(with English Nature and the SWT) have felled the conifers that were at the
bottom of the slope to the W and some of those behind the tor to the E.
They have also cleared the small scrub trees that were growing all over
these slopes as part of the 'Back to Purple' campaign. The steeply dipping
beds of the quartzite can be made out although it is confused slightly by
the strong joints that run at 90° to the bedding and a second set that run
90° to the first set. This jointing pattern is the same as described for
the other tors on the ridge (ref.1). Along the ridge (S) from this tor
there is further piles of bolder scree (and in-situ rock) in which pieces of
the beach conglomerate can be found. There are pieces with a range of
textures from poorly sorted coarse conglomerate (with sub-rounded quartz
pebbles of a up to 10 mm in diameter) to the main blocks of the tors which
are fine grained. The conglomerate also contain pebbles which are of other
material such as purple Longmyndian sandstone. Quartz veins can be found in
many of the pieces some of which show well formed (if small) crystals. From
the top of the ridge there are views all round such as W to Mitchells Fold
and Corndon; S down the valley towards Lydham and N up the rest of the
Stiperstones ridge. Also there is a fenced off area which is marked on the
BGS map as a shaft. This is cut down into the quartzite to a depth of about
15 m. It is conceivable that the W end of this excavation stops against the
Mytton Flags which form the slope below the quartzite ridge. It is not
possible to tell this for certain as the shaft is fenced and has very steep
and therefore dangerous sides. Outside the fencing there is a small patch
of gravel type material that looks much like the mine waste at the Bog
Mine. This could have been a tip from this shaft and contains minerals such
as quartz; calcite and barite. |
There is a car park just below the outcrop on the E side of the Bog to
Linely road. There is a footpath that passes round the base of the tor and
continues along the ridge. This path is not on the Explorer map (216) but is
signed on the ground just up the track from the carpark. The shaft is off
the path but at present it is easy to get down the slope. |
RIGS Yes. This is a good site with mining interest as well as the frost
shattered tor. It has easy access and carparking and (on a good day!) has
good views to the other tors. |
Structure and Sedimentology/Stratigraphy |
|
0052 |
SO 357 978 |
Bog Mine - Stiperstones |
Mine/adit |
Ordovician |
Mine workings below the Stiperstones ridge. |
This site has been partly reclaimed and re-vegetated (with limited success)
with some of the mine waste being removed by farmers for hardcore. Some of
the mine buildings are still standing along with many more foundations. The
waste tips are still evident and the white minerals (barite calcite and
quartz) are still very much in evidence especially where erosion has
revealed new material. There are information panels here explaining the
mining and therefore much of the geology. |
Large car park with information board and mine buildings; about 2.5 km south
of Stiperstones village (where there is a pub!). In summer there is a shop
and excellent tea room operating at the old school; this also serves as a
field centre. |
RIGS Yes. This is an important mine site and one of the most which are
accessible to the general public. There are some minerals to be found and
it already has interpretation in place. |
Mineralogy/Petrology |
|
0062 |
SJ 390 046 |
Poles Coppice - Pontesbury |
Quarry (disused) |
Ordovician: Arenig Series: Shelve Group: Stiperstones Quartzite (BGS Shelve
Area). |
This site is on high ground towards the N end of the SW/NE trending ridge
made by the resistant Stiperstones Quartzite that continues from the
Stiperstones. To the N is the low undulating ground of the edge of the
North Shropshire plain. |
The main quarry (and the only one with an obvious path into it) is very
large; about 200 m across and 20 m high. However there is a lot of scrub on
the quarry floor and some up the faces at either end. There is a clear
patch in the middle of the quarry but the view of it is still becoming
obscured by the trees. The faces are very steep and there is a lot of loose
scree at the foot of them that makes it difficult to reach the in-situ
rock. The bedding is almost vertical (dip W) and is slightly undulose in
places. It is difficult to determine the grade of the quartzite in the
different beds without hammering sst the faces. The loose material
indicates that the quartzite ranges from very fine to coarse. There are
very few thin siltstone bands between the quartzite beds. There is one
obvious fault towards the top of the face. Above the fault the rock has
iron rich staining whilst the beds just below can be seen to bend up as an
affect of fault drag. There are tips of quartzite 'rubble' all over the
floor of the quarry amongst the trees. There are two other smaller quarries
in the vicinity (as marked on the OS Pathfinder map). Neither of theses are
accessible but the 'black route' through the nature reserve pass between
them and allow a view down in to them. |
These quarries are within the County Councils nature reserve area and can be
reached by following their colour coded paths. The nearest car park is the
one at the N end of the reserve which is reached from Pontesbury. |
RIGS Yes. This is a good site which demonstrates the nature of the
Stiperstones Quartzite with some faulting. It is a large site with easy and
access close to centres of population and suitable for large groups. |
Structure and Sedimentology/Stratigraphy |
|
0063 |
SO 390 858 |
Edgton Farm (Dunslow) |
Bank |
Silurian: Ludlow Shales. |
The exposure is at the base of a steep scarp slope of a small ridge running
NE/SW. From the top of the scarp there are good views of the surrounding
hills including the Stiperstones ridge Corndon the Longmynd Caradoc the Clee
Hills and Bury Ditches. |
The exposures are mostly on the banks of a track to the left of where the
Shropshire Way climbs the scarp slope of the ridge. The outcrops themselves
are obscured slightly by lichen and moss but they generally are not
overgrown so the structure is clearly visible. They show thinly bedded
siltstone which is calciferous in places but doesn't appear to contain any
calcareous nodules. The beds dip gently to the SE and are usually 10 mm
thick or less. Graptolites are plentiful and are found in various states of
preservation. They can be found in the abundant loose material which lines
the track. Other fossils such as orthocones can also be found but these seem
to be less common. There are also small exposures in the lane that the
footpath follows from the road. However these are quite vegetated and only
really suitable for research purposes. |
From Edgton follow the Shropshire Way south through a few gates. The public
path climbs the steep scarp slope up the fence line but the exposures are on
the track that bends to the left. Park on the road in Edgton. Or there is
lots of space at the village hall on the west side of the village if the
gates are open. |
RIGS Yes. Designation as an easily accessible safe place to study rocks of a
graptolitic facies. It provides a good comparison to the areas of Edgton
Limestone in the area and also with the other graptolitic siltstones at the
west side of the village. There are also good views from just a bit further
up the path making it an interesting geomorphological site. |
Fossils |
|
0064 |
SO 382 831 |
Burrow Hill Fort - Hopesay |
Crag |
Silurian: Ludlow Series (undivided W of C/S fault; BGS Sheet 166). |
The hill fort has been built on the higher summit of a two-summit ridge.
There are good 360° views of the surrounding countryside. |
There are several small outcrops (max of a few metres in each direction)
incorporated into the banks of this impressive hill fort. The ones found on
this visit were at the SW end of the fort in the vicinity of the highest
point. They showed flaggy uneven beds of siltstone (<10 mm to 50 mm thick)
dipping at about 20° to the S. There was not much loose material by the
outcrops but near the S entrance to the fort there is an abundance of loose
scree. This proved to be unfossiliferous but a few pieces showed some
bioturbation. The view from the top is very good. Because the fort area
has not been forested there is a clear view of 360° (only obscured by a few
old oak trees). This shows all the local hills and as far as the Clee Hills
Caradoc etc. Along the tracks that run below the fort to the west there are
further outcrops partly exposed due to the recent clearance work in this
area. These mostly show thinly bedding siltstones dipping gently to the S.
However at GR 379831 (just by a track junction) there is an abrupt change of
dip (from about 10°S to 45° and more to the E); disturbance and jointing of
the beds. This would appear to be a fault zone as the structure is lost for
a few cm. Despite the enormous amount of loose material that covers the
tracks in places there is very little evidence of fossils. The rock is
quite micaceous in places. |
There is no public path to the hill fort but there are tracks through the
surrounding woodland that lead to the fenced off fort. The easiest of these
to follow are up the W side of the hill. These fork off of a path that
follows the Shropshire Way from Hopesay. Park in Hopesay. |
RIGS Yes. RIGS designation particularly for its view of the surrounding
countryside. There is also some interesting (if small outcrops) with
possible faulting. |
Geomorphology/Landscape |
|
0068 |
SO 448 837 |
Top of Halford Wood |
Spoil heaps |
Silurian: Ludlow Series: Aymestry Group |
Spoil heaps are on top of a small scarp slope formed from Aymestry
Limestone. 360 degree views around Shropshire including Clee Hills; Stretton
Hills; Whitcliff; Clun Hills; down to The Malverns and west to Radnor
Forest. |
Spoil heaps made up of very fossiliferous; nodular Aymestry limestone each
about 4m high. Heaps are stable. Calcified fossils include several types of
brachiopod and crinoid. Disused quarry as marked on Pathfinder map is no
longer discernible. Great views as described above. |
Via public footpath from west of Whettleton Pool (444830) about 750 m up
scarp slope. Heaps and views are just of the path beyond the top of the
wood. |
RIGS Yes. The landscape views are the best showing geomorphology of
Shropshire. Plus some fossils and rocks showing nature of Aymestry limestone
which makes up the scarp you are on. |
Geomorphology/Landscape |
|
0071 |
SO 512 741 |
Ludford Corner |
Cutting (road/railway) |
Silurian: Ludlow Series; transition to Pridoli Series. |
Roadside cutting on junction |
Exposure of thin beds (<50 mm) of siltstone. Transition from Silurian to
Pridoli; formerly considered to be Devonian. Plaque at base (behind bench)
tells of Murchison's interest in the Bone Bed. This is now backfilled but
had become a deep slot due to excavation for fossils (an exposure has been
deliberately left free from burial 50 m up the road by the speed limit
sign). Main exposure is on the junction of Richards Castle road and
Whitcliffe road. It continues up both sides for about 50 m but space is
restricted and the road is very busy. This was once the classic locality for
the Ludlow Bone Bed. |
On junction of roads. Parking for two or three cars in minor road opposite |
RIGS Yes. As part of a designation that covers the whole of the Whitcliffe
Common area. |
Fossils and Sedimentology/Stratigraphy |
|
0072 |
SO 288 742 |
Lurkenhope - Stowe |
Quarry (disused) |
Silurian: Ludlow Series (ref.1). |
This site is on a road which follows a steep sided; narrow; v-shaped valley. |
The main quarry site has become very overgrown with brambles and small
trees. This along with the amount of loose scree on the steep slopes makes
it very difficult to reach the higher outcrops. The lower parts of the
quarry are more accessible and show massive bedded units up to 600 mm thick
with thin shale partings. The lower parts appear to be more massive than
the higher beds which are of a more flaggy nature. At the top of the quarry
there are notable strong sub-vertical joints trending almost N/S. The
exposure continues SE along the NE side of the road. A wide verge makes
this an easily accessible and safe place to study. The most obvious feature
is the fault zone; just to the right of the quarry; that separates beds
dipping about 20°NW with from others that are almost horizontal. The fault
zone contains very broken and distorted beds. On the rock exposed closest
to the road and at ground level there is a covering of calcite along one
plane. A lot of the loose material in this area shows degrees of calcite
mineralization. To the right of the fault zone the rocks appear to form a
very flat syncline. In these beds the sedimentary features are clearly visible in the almost cyclic bedding of massive
siltstone beds separated by a few cms of fine laminated siltstone. A few
fossils were found scattered in the siltstone with the occasional bedding
plane having a covering of brachiopods. |
This site is on the A488 Knighton to Clun road. It is found on the NE side
just on the bend N of the farm at Lurkenhope. Parking is possible on the
wide verge infront of the outcrop although this can be very soft in wet
weather. |
RIGS Yes. Designated for its accessibility and usefulness for large groups
to study features associated with sedimentation (cyclic features resembling
turbidites) thin layers of allogenic fossils and structural features of
faults and folds.. |
Fossils and Sedimentology/Stratigraphy |
|
0075 |
SO 322 732 |
Tournett - Stowe near Knighton |
Quarry (disused) |
Silurian: Upper Ludlow Series |
Quarry cut into roadside bank/cliff on edge of River Teme floodplain. |
Large quarry up to 10 m high. Thinly bedded (shaley) siltstones dip into
hillside. Further exposures occur along the road towards Weston for about
200 m. Some parts badly weathered and distorted by tree roots. Lots of
loose shaley material but few fossils found. (M.Allbutt:- 'Orthocone;
graptolites expected). Some; but very few; calcareous nodules within the
shaley bedding. |
Bucknell to Knighton road past on RHS past Weston. Bucknell 3.75 km.
Restricted parking; one car might fit in quarry but it is very muddy. Narrow
road |
RIGS Yes. Good outcrops with some fossils. Very good structure in parts.
Large enough for good sized group except lack of parking. |
Fossils |
|
0083 |
SO 348 759 |
Bedstone Hill - Bedstone |
Quarry (disused) |
Silurian: Cefn Einion Formation. |
Quarry has been cut into the side of the hill above a very steep narrow
valley. |
This is a square sided quarry with three faces up to about 6 m high and 10 m
long. The left and right hand faces trend N/S whilst the back face is at
90° i.e. trends E/W. There is a lot of rubbish which obscures about half of
the back face. The other faces are clear and accessible. The rock is
mostly flaggy siltstone / fine sandstone with some more massive beds. There
are a few beds of finer lithology that are obvious as units about 60 mm
thick. The RH face is the more interesting as it is less flat than the
other so provides a section showing the dip of the bedding as well as faces
parallel to the strike. There is some spheroidal weathering and mm scale
laminations can be seen in some of the units on this side. Fossils were
quite numerous in the abundant loose material but their source in the
in-situ rocks was not apparent as obvious fossiliferous bands. |
This site is along one of the many forest tracks within this plantation. In
Bedstone village take the left hand turn to Mynd; then take the first
turning left signed 'Darky Dale'. This road can be followed for about 1.4
km until a track leaves to the left at a 'cross-roads'. Park here if it is
clear that there are no forestry operations in the area. Follow the rack to
the left. The quarry will be seen on the LHS of the track after about 400
m. It is fenced off from the track as the faces are vertical at this
point. Go through the trees beyond the quarry to reach the entrance. It is
also possible to park at the end of the metalled road where several paths
meet or at the Forestry Commission car park at Hopton Titterhill but that
then requires a long walk to reach the site. |
RIGS Yes. This site has some interesting material and is a fossiliferous and
accessible example of the Cefn Einion Formation. However the rubbish does
present a hazard that should be removed. If this was cleared the site would
be suitable for reasonably large parties. |
Fossils and Sedimentology/Stratigraphy |
|
0085 |
SO 358 777 |
Hopton Park - Hopton Castle |
Quarry (disused) |
Silurian: Bailey Hill Formation. |
This quarry is cut into the bottom of the steep sided Hopton Titterhill
above the undulating valley which can be seen to the NE. |
This quarry covers a large area and is reminiscent of the spoil tips of a
Welsh slate mine. Most of the area is covered in loose material of all
sizes up to several feet across. There a few in situ exposures. One of
these (about 3 m by 10 m) is found at the top along a track that continues
directly up the hill into the woodland. Here it shows units 100-150 mm
thick of dark siltstone and fine sandstone. The rocks of the outcrop look
fairly uniform in terms of lithology as do the loose pieces. The loose
material shows a good number of features that indicate these are turbidite
beds. These include tool marks and flute casts as well as other evidence
for scouring. Unfortunately on this visit no distinctive marks could be
found on the many in situ bedding planes visible to indicate a direction of
movement. Other pieces showed mm scale laminations and light and dark
banding. There was occasional evidence of calcite mineralisation with some
surfaces having a covering of calcite. No fossils were found. |
From the B4367 Craven Arms to Bucknell road take the RH turning at Hopton
Heath and turn immediately left to Hopton Castle. Park at the far end of
the village and follow the unmarked path through three gates and follow the
track on to a forth at the bottom of the wood. The quarry is directly S of
the gate into the wood on the next track up. Either follow the track round
to the left or take the short cut straight up the bank in front of you.
This site is also on the Hopton Mountain Bike trail route; post No.8. |
RIGS Yes. It has an abundance of material showing various surface features
such as tool marks (on all scales). There is loose material to study as well
as in-situ rock. Potential for finding such nicely 'sculpted' rocks. The
site is big enough for the largest of groups and has relatively easy access. |
Sedimentology/Stratigraphy |
|
0178 |
SO 505 746 |
Dinham Quarry - Ludlow |
Quarry (disused) |
Silurian: Ludlow Series: Whitcliffe Beds. |
Large quarry cut into base of Whitcliffe; behind Clive Cottages |
The largest E-W trending face of the main quarry is about 150 m long and ~25
m high. Beds dip very gently to the NW looking almost horizontal in the
main face but overall the dip of the Whitcliffe Beds here is 10° towards the
north-north-west (consistent with its position on the northern flank of the
Ludlow Anticline). Fine calcareous sst and sltst. Bedding sometimes
undulates and is uneven and/or discontinuous. Fossil bands can be seen in
the faces e.g. one that is 30 mm thick about 1.3 m off the quarry floor to
the left of the centre of the main face. Fossils such as brachiopods and
bryozoans are also to be found in the loose material at the base of the
faces. Some cross-bedding on a mm scale can also be seen within a lot of
the beds. Spheroidal weathering is apparent in places. There are further
exposures that reveal the higher beds in the sequence. These are above and
to the E of the main quarry. They show similar features including trace
fossils and bioturbation on some of the loose material. Two prominent
volcanic ash bands about one third of the way up the main face. In medieval
times this quarry was owned by Bromfield Priory and operated on their
behalf. |
Park at Dinham Bridge. The quarry is on the left hand side of the road
leading up to Whitcliffe and is reached via a small path just before (and on
the opposite side of) the caravan park (behind Clive Cottages) |
RIGS Yes. It is a very impressive quarry which is easy to access and
relatively safe for parties of all ages and sizes. It could be combined
with other Whitcliffe sites. |
Fossils and Sedimentology/Stratigraphy |
|
0196 |
SO 305 839 |
Colstey (Bury Ditches W) |
Quarry (disused) |
Silurian: Cefn Einion Formation. |
Quarry and exposure at side of track that runs down to small river running
between Colstey Wood and Red Wood. |
The small quarry has a total height of about 5 m and a length of 7 m along
the E/W exposure. At the base the beds tend to be flaggy but they become
more massive towards the top. They are siltstone and fine sandstone. Some
pieces of loose material contain abundant fossils including several
brachiopods and one large Serpulites was found. There is some undulose
bedding and the beds appear to dip about 20°W. There are further exposure
in the bank on the RHS of the track below the quarry towards the stream.
These beds can be seen behind the brambles for about 10 m. As the track
bends and crosses the stream there is an exposure on either side of the
stream. The one to the right (NW) of the stream is the better exposure as
it is less vegetated. This is about 5m x 10m and shows massive units up to
150 mm thick and more flaggy units only 10 mm thick. The bedding surfaces
appear uneven and in-filled burrows are visible on the surfaces of some of
the loose material; with the in-fill being paler than the surrounding rock.
Very few body fossils were found here except one bit of an orthocone. The
rocks of the other side appear to be much the same but are covered in moss;
lichen and scrub. There is another small exposure on the track running down
next to the stream but this is small and access is more difficult due to
brambles and loose material underfoot. |
This is along one of the many forest tracks in this area. The nearest
parking is at the Colstey Wood entrance. The site is down the main track
past the barrier. Alternative parking is at the Forestry Commission Carpark
for Bury Ditches. This is further from this site but is a larger carpark
and allows easier access to other sites in the Bury Ditches area. |
RIGS Yes. This should be a RIGS in conjunction with other sites in the Bury
Ditches are to show different facies within the Ludlow Series. |
Fossils and Sedimentology/Stratigraphy |
|
0198 |
SO 313 819 |
Croveats Lane - Clun (NE) |
Bank |
Silurian: Downton (Ludlow Bone Bed) according to ref.1. |
The path climbs the steep sided Radnor Wood and gives good views back over
Clun and the hills that surround it. |
This exposure reveals the Bone Bed towards the top end. This is revealed as
black layers (totalling about 80 mm in thickness) that are obviously
different from the surrounding layers. The loose pieces show some of this
very dark material to be of very broken fragments covering pieces of more
silty rock. They also show other features that may be fish fossils. The
total exposure is about 0.5 m high and 7 m long. The other layers appear to
be unevenly bedded flaggy siltstone which dip at about 5°SW. The
surrounding loose material also contains a few small pieces of red medium
grained sandstone. Gastropod fossils were found in some loose siltstone
blocks. Ref.1 states this as being a site for Thelodus parvidens fauna
Cyathaspis Sclerodus and acanthodian. |
Park in the Community Area car park in Clun and continue up the road on foot
past the Youth Hostel until the footpath branches off over the field to the
right. Follow this path and then the track up the sunken lane. Pass through
two gates. The site is on the LHS just beyond the second gate where the path
goes through a very low 'cutting'. |
RIGS Yes. This is perhaps the most easily accessible exposure of Bone Bed
outside Ludlow so gives a better understanding of this important marker
horizon. There are fossils to be found in the path and the dark fragmented
material is quite clear in the exposure. |
Fossils and Sedimentology/Stratigraphy |
|
0199 |
SO 314 851 |
Acton Bank - Lydbury North |
Quarry (disused) |
Silurian: Cefn Einion Formation. |
This quarry is cut into a small isolated ridge trending NE/SW on otherwise
flat land at the junction of several valleys. |
There are three quarries at this site.
The first is mostly behind a barn and therefore is not very accessible but
clearly shows flaggy bedding. Along the footpath is the next and most
accessible of the outcrops. This shows more massive beds which dip gently
south and which are up to 200 mm thick. Some of these show internal
laminations. There are some flaggy beds of just 10 mm thick. Over the
surface of the face and in some of the joints there is a weathered clay-like
material containing clasts of many sizes. There is a large amount of debris
in front of this outcrop - the larger pieces of which show the uneven nature
of the bedding surfaces. To the left of this quarry the outcrop continues
for several 10's of meters but it becomes less accessible. Here the bedding
is again more flaggy in nature with beds of just a few cm's in thickness.
The site appears to be quite stable but there are some overhangs which
obviously should be avoided. |
This site is to the east of the public footpath that runs along the side of
Acton Bank from Acton. It is at the beginning of the path where it crosses
the first stile. Park in Acton or on approach but avoid blocking gateways.
M. Allbutt suggests asking at the farm but it is not clear which building in
Acton this is. Permission should be sort for study of the quarry behind the
barn as this is not on the footpath. |
RIGS Yes. Suitability for teaching purposes (including large groups) for
study and interpretation of faulting and sedimentary features; in particular
the development of slump structures relevant to its position on the Silurian
shelf/basin margins. |
Structure and Sedimentology/Stratigraphy |
|
0200 |
SO 315 874 |
Colebatch (W) - Bishop's Castle |
Quarry (disused) |
Silurian: Bailey Hill Formation (ref.1). |
This is cut into a sharp slope just above a small meandering stream. |
This quarry shows interbedding of massive and shaley units with a steep dip
to the SE. The lithologies include dark quite micaceous fine sandstone
siltstone and a few pieces of rich brown mudstone. The massive units are
about 150 mm thick and are separated by thicker units of the more shaley
material. This interbedding follows quite a regular pattern. The beds tend
to be quite uneven with some large nodules and spheroidal weathering in
places. There is some deformation of the LH end of the mainly NW/SE
trending face. The total exposure is about 8 m high by 30 m and most of the
beds are accessible at some point. There is an abundance of loose material
that lies in the bottom of the quarry and where there has been some recent
excavation. This shows some bioturbation but no fossils. Much of if shows
very rusty weathering and many display an oily looking sheen. |
Turn W off the Bishop's Castle to Clun road in Colebatch. After about 300 m
a footpath follows a track to the right and over the stream. The quarry is
visible beyond the gate in the field. Park on the verge just before the
track or in Colebatch. Other facilities can be found in Bishop's Castle. |
RIGS Yes. RIGS designation due to its suitability for teaching purposes
giving access to large groups for study and interpretation of (probable)
turbidite sequences and related sedimentary features. In the context of a
position on Silurian shelf/basin margins comparison with near-by Acton Bank
is particularly relevant. |
Sedimentology/Stratigraphy |
|
0202 |
SO 322 834 |
Stepple Knoll (N) |
Quarry (disused) |
Silurian: Cefn Einion Formation. |
This forest track runs up a small valley on the side of the prominent;
conical shaped hill. The toposcope on the summit gives a guide to the good
360° views of the surrounding countryside. |
This excavation is now covered in young fir trees which are growing amongst
the loose material on the bedding surfaces. Some of the rock is still
unobstructed and the structure of the beds is visible even through the
trees. The rock is very broken and blocky. It dips about 20°NW. The
bedding planes are quite undulose in places. Some fossils were found
including brachiopods and ostracods but I did not find any of the shell
coquina reported by M. Allbutt. The quarry is about 50 m long (including
vegetated areas to either side of the main face) and a maximum of about 5 m
high. There are no dangerous overhangs. |
Park at the Forestry Commission car park and take the lower track marked
with a red banded post. Follow this track until a tight bend in a small
valley. At this point take the grassy path down the stream to the track
below which you should follow to the right. The quarry is just up the slope
to the right where this track meets another. |
RIGS Yes. Part of the larger RIGS site that takes in other sites in the Bury
Ditches area as they show how the rocks change throughout this part of the
Ludlow Series. |
Fossils and Sedimentology/Stratigraphy |
|
0203 |
SO 325 831 |
Stepple Farm (N) |
Quarry (disused) |
Silurian: Knucklas Castle Formation. |
This is a quarry on the side of a valley at the base of the conical shaped
Stepple Knoll and Sunny Hill. |
This curved excavation is about 4 m high by about 40 m. It shows the
characteristic flat; shaley; laminated; bedding of the Knucklas Castle Beds.
The beds appear to dip gently WNW. There is most loose material on the RHS
(E) a lot of which shows an oily sheen on many of the surfaces. On the LHS
there is less loose material and the structure is more readily apparent.
Some of the debris shows there are some quite mica-rich band within this
horizon. This is a very open and safe site with easy access to all the
beds. |
This site is just off the public footpath that runs from Bury Ditches to
Stepple Farm. It is best to park in the Forestry Commission carpark and
walk along the waymarked tracks. The footpath runs around the top of this
excavation. |
RIGS Yes. To be considered as a RIGS site in conjunction with others in the
Bury Ditches area to show the different facies that were in the area during
the Ludlow Series. |
Sedimentology/Stratigraphy |
|
0204 |
SO 325 834 |
Bury Ditches (SSW) - Dawes lines - Lydbury North |
Quarry (disused) |
Silurian: Cefn Einion Formation? |
Track runs along contours around the bottom of the prominent; conical shaped
hill. Toposcope on the summit gives a guide to the good 360° views of
surrounding countryside. |
An outcrop that runs along the track between two small quarries (SO329836 to
the E and SO325834 to the W). The beds are a few cm thick (compared with
mm's thick to the east). Some beds are more calciferous and these have more
rounded weathered edges than the more shaley beds. These more massive beds
are interbedded with fine shaley beds. Some fossils were found but the
fauna is still quite sparse. Allbutt describes this as being a transition
between the shaley KC beds and the more undulate and flaggy CEF. In the
western quarry the beds are obviously thicker than they are at other sites
to the east. A calcareous nodule was on the floor and there are others in
the quarry face. The beds appear to dip NW. Fossils are evident on the
bedding surfaces of the yellower; more sandy pieces. These consist mostly of
small brachiopods. The exposure that has continued along the length of the
track from the car park to the east finally peters out just before the track
reaches the small valley and bends around tightly. |
Park at the Forestry Commission car park and follow the lower track with the
red banded post. The quarries are about 1 km along this track. Stay on the
upper of the two track where there is a choice. |
RIGS Yes. As part of RIGS to include all the sites in the Bury Ditches area
which show the different facies of this part of the Ludlow Series.
Designated ‘as showing a continuous section through the transition between
two principle rock formations of the area. It specifically demonstrates the
effects of shallowing of a depositional basin whereby pelagic and oxic
sediments become overlain by incoming traction sediments with concominant
changes in lithology and fauna. |
Fossils and Sedimentology/Stratigraphy |
|
0206 |
SO 329 836 |
Bury Ditches Clun (SE) |
Track/roadside |
Silurian: Knucklas Castle Formation. |
Track runs along contours around the bottom of the prominent conical shaped
hill. Toposcope on the summit gives a guide to the good 360° views of
surrounding countryside. |
This is a small excavation (3 m high x 10 m) in the bank of the track-side.
Here the bedding is mostly thin but there are some more massive units.
There is some strong jointing and some more calciferous areas. Rock is
exposed in the track-side for most of its length. The exposures are only
ever a metre high at the most and are often less. However walking along the
track you can get a good a good feel for the structure of this thinly bedded
siltstone. The beds tend to be on a mm scale and are rarely more than 10 mm
thick. The angle of dip appears to vary slightly as does its direction. M.
Allbutt suggests there is a flat anticline visible in this section. There is
lots of loose material along the track but this is very broken and consists
mostly of pieces just a few cm in the largest direction. The beds get
slightly more massive towards the SW end of this section at a small quarry
(see SO329836). No fossils were found in any of the loose material along
this section. |
Park at the Bury Ditches carpark and take the lower track marked with a red
banded post. The exposure is on the N side of this track just at the fork
of two tracks. |
RIGS Yes. To show the progression through the various horizons of the Ludlow
Series. |
Fossils and Sedimentology/Stratigraphy |
|
0207 |
SO 329 838 |
Bury Ditches Clun (E) |
Quarry (disused) |
Silurian: Cefn Einion Formation. |
Quarry in ditch of hill fort which is on top of Sunny Hill. From the top
there are great views interpreted with the aid of a toposcope. |
This is a small pit in the inner ditch of the hill fort. A lot of the pit
is covered in grass but there is still a clear exposure on the back wall.
It shows siltstone dipping gently to the west. M. Allbutt mentions areas of
diverse fauna but only a few small brachiopods were found on this survey. A
lot of the loose material that may have been around here is covered in grass
but there is still sufficient material to be found. On the track back
towards the main car park a tree has fallen over revealing a large amount of
loose material beneath its roots. This is a pile of recently exposed (and
therefore quite 'clean') flaggy siltstone containing a few fossils. |
Park at the Forestry Commission carpark for Bury Ditches and follow the main
track up to the hill fort. The site is over the stile and to the right of
the E entrance to the fort. |
RIGS Yes. To be included in the RIGS of this area; very close to the car
park and to the summit which is good from a geomorphological point of view. |
Geomorphology/Landscape |
|
0217 |
SO 352 811 |
Purslow (W) - Clunbury |
Quarry |
Silurian: Bailey Hill Formation. |
Small quarry on lower slopes of wide valley of the River Clun. |
The quarry is about 5 m high by about 20 m which trends NNW and shows mostly
massive beds of fine dark grey sandstone and siltstone. There is a lot of
loose material many pieces of which show closely packed and aligned tool
marks or uneven bedding surfaces. Other pieces show an oily sheen. There
is one area which may show a possible fault. This is a 1.5 m wide vertical
region of very broken rock and clay-like material where the structure seen
in the rest of the face is no longer visible. Some areas have been stained
by iron rich deposits giving them a rusty appearance. The faces seem fairly
safe with just a few areas where there is a thick soil overhang. This quarry has been much extended. Dips range from
zero to 45° towards the SE quadrant. The BGS sheet shows a dip arrow of 11°
to SSE. What was previously taken as evidence of slumping is now abundantly
confirmed as due to large scale slumping combined with two instances of
smaller 1 m scale slump folds verging to the SE. In detail one of these
shows that slumping is the cause of a millimetre scale corrugation of
bedding surfaces examples of which are prolific amongst the talus. This
quarry provides another exposure of slumped Bailey Hill beds in the eastern
part of Ref 1; see cross-referenced reports |
This Quarry is on the N side of the B4368; Clun to Craven Arms road about
750 m west of Purslow. It is open to the road and at present allows plenty
of space for parking. |
RIGS Yes. RIGS designation because this offers the most accessible local
exposure of slumped Bailey Hill beds which offers the opportunity to study
slumping (typical of this horizon) and possibly faulting. However as a
‘working quarry’ one would wish to avoid any possibility for conflict with
owner/occupier. |
Structure and Sedimentology/Stratigraphy |
|
0218 |
SO 353 834 |
Kempton (NW) - Clunbury |
Quarry (disused) |
Silurian: Bailey Hill Formation. |
Quarry in the ridge that forms the NE slope of a small valley. |
This is quite an impressive almost circular quarry now used as a dump for
tyres and fencing. Despite the rubbish a lot of the floor is quite clear
and many of the faces are easily accessible. The highest faces are about 10
m high but some are covered in trees and scree. Slump bedding is visible
especially on the face to the NW of the entrance. Here the beds are
contorted into tight folds. The area of folding is quite obvious as it has
weathered differently to other areas. Other faces show areas of flat;
continuous bedding but which has bowed down slightly in the middle over a
distance of a few meters. The bowed beds are a few cm thick with more
massive units above and below. There is a lot of loose material on the RHS
of the entrance some of which shows slight bioturbation. Some of the faces
and talus slopes are quite unstable but there is plenty of safe areas to
study. |
Park at Kempton (there is a lay-by by a telephone box on the B4385) and take
the footpath that goes up the valley towards Lodge Farm. The quarry is on
the RHS of the track just before a cattle grid. |
RIGS Yes. RIGS because of its several examples of well-formed slump bedding
of a quality which would allow quantitative measurements to establish the
direction and inclination of the palaeoslope on which they occurred This is
also a very easily accessible site showing features that would be of
interest to people of most knowledge levels. |
Sedimentology/Stratigraphy |
|
0222 |
SO 378 815 |
Oaker Wood (S) - Hopesay. |
Quarry (disused) |
Silurian: Ludlow Series (upper; ref.1). |
Quarry at the end of an elongated hill with two summits; the northernmost
and highest of which is topped by Burrow Hill Fort giving 360° view of the
surrounding countryside. |
A large quarry with clear open faces showing units of siltstones up to 2 m
thick dipping about 20°SE. The beds get thinner towards the top of the
faces that are about 30 m high and 60 m wide. There is quite a lot of loose
material which shows some bioturbation and some fossils. The fossils
(brachiopods) are patchy with some loose pieces showing a lot on the bedding
surfaces whilst others only show a few. The beds themselves appear to be
featureless. To the LHS of the quarry entrance there is an area under an
overhang that shows beds apparently dipping to the N; it looks like a
shallow syncline. However there also appears to be a fault zone in this
region which may have caused some disturbance of the dip. The floor of the
quarry is covered in low vegetation and some rubbish. The faces are also
covered in places by brambles ivy and small trees but there is access to the
base of the faces. There is no access to higher up the faces as they are
vertical. |
This site is just to the N of the B4368 about 1.3 km W of Aston on Clun. It
is along a footpath which is also a track so vehicles can reach the quarry
although permission should be sought for this. There is a piece of wire
that has been put across the entrance but this is the only barrier. |
RIGS Yes. This is the type-locality of Salopina lunata. Capable of
accommodating large groups and shows bedding typical of this horizon. |
Fossils and Sedimentology/Stratigraphy |
|
0258 |
SO 397 865 |
Ridgeway Hill |
Quarry |
Silurian: Ludlow Series: Edgton Limestone (BGS Sheet 166). |
Quarry is cut into the end of a 'hogback' ridge which runs NE/SW. There are
good views from this ridge especially up the Stretton Valley to Caradoc and
the Lawley. |
At the LHS of the quarry there is a metre or so of deformed nodular
discontinuous beds belonging to the Edgton Limestone that pass up into
flatter more continuous calciferous siltstone beds. Also in this area there
appears to be a fault with fault beccia. The dip is generally in a SW
direction. Due to the way the quarry has been cut this results in on face
being a bedding plane. This clearly shows the sub-vertical N/S trending
joints which are mostly in-filled with calcite. There is abundant evidence
of calcite mineralisation and there are good pieces to be found amongst the
loose material. At the back of the quarry there is a banded region showing
paler more calciferous beds inter-bedded with darker ones. The paler beds
have weathered to a yellow colour and often contain a lot of small solution
hollows. No identifiable fossils were found on this visit. |
This is on the junction of three paths the shortest of which leaves the
Edgton to Horderley road opposite Ridgeway Farm. One path continues along
the ridge from which the good views can be seen. Park on the verge or in
Edgton. |
RIGS Yes. This is an impressive quarry which may have been reworked recently
as there is a large pile of loose material in the centre; this should be
avoided as it looks quite unstable. There is plenty of loose material
elsewhere. Designated as a RIGS as an easily accessible site of this
'limestone' as a comparison with other lithologies in the region and for
studies of calcite mineralization and faulting. It is a definitive location
of rock of Wenlock age west of the Church Stretton fault and is a superb
viewpoint for a landscape developed from the underlying geology. |
Fossils and Sedimentology/Stratigraphy |
|
0278 |
SO 408 871 |
Horderley - Edgton |
Natural exposure |
Silurian: Wenlock Series: Edgton Limestone (Equivalent to Wenlock Limestone
and Tickwood Beds) or calcareous Wenlock Shales? (BGS SO48; Craven Arms
1:25000). |
Exposure above track on S side of River Onny where spring emerges from
hillside. |
This is an exposure above the track that crosses the Onny River at
Horderley. It extends for about 20 m along the track and is about 3 m
high. There are two lithologies present. There are siltstone bands and
much paler bands which are calciferous siltstone; verging on limestone. The
softer fawn coloured bands are bounded by very thin (2 mm) harder layers.
Some of the rock looks very pale and chalky whilst others are covered in
rust staining indicating iron rich rock. There is some loose material which
is generally less broken and fissile than that across the road at GR
SO408874 indicating a change of lithology between the two sites. This could
be the transition between Wenlock Shales and Edgton Limestone. There was
some very bioclastic limestone pieces but these could be from the hardcore
used on the track although they are found quite high up the bank. Few other
fossils were found in the rest of the rock. |
This site is on the RHS of a footpath that leaves the A489 at Horderley and
crosses to the S side of the River Onny. It is about 50 m along this path
from the road. |
RIGS Yes. This is an easily accessible safe site that demonstrates a change
in lithology and is close to other sites so providing a 'story' for an
itinerary. Suitable for small groups. Transition between Silurian Wenlock
Shales and ‘Edgton Limestone’ as mapped by BGS circa 1964. The latter is
now better regarded as the Edgton Limestone member of the Aston Mudstone
Foramtion of the later BGS Sheet 165 of 1994. Boundary also includes a site
of active tufa formation along old river cliff. |
Fossils |
|
0283 |
SO 410 852 |
Longville Plantation (S) |
Quarry (disused) |
Ordovician: Caradoc: Chatwall Sandstone and Chatwall Flags (transition). |
Cut into bottom of steep sided hill. |
About 85% of this quarry is now covered in vegetation; mostly brambles and
small diameter trees some of which have fallen over. The best exposures are
on the back wall which shows steeply dipping beds. There appear to be
localised changes in dip with the beds near the top looking almost
horizontal. Some of the cleaner faces show characteristic purple banding in
massive sandstone. Some other layers show much thinner beds of finer
material. There is a lot of loose material on the floor of the quarry which
show a number of features including: bioturbation; worm burrows; flute
casts; slickensides and ripple marks. The site has been noted for the
transition between Chatwall Sandstone and Flags and haematite staining in
certain areas (Allbutt). A lot of the lower slopes look quite unstable and
the upper beds cannot be reached safely at present. |
Follow the permissive path through the bottom of the wood from the entrance
on the road about 750 m NW of Cheney Longville. The quarry is situated on
the left hand side just before the path reaches the stream at the bottom of
the hill. Park at the entrance. Other facilities in Craven Arms. |
RIGS Yes. RIGS for the following reasons: ‘the stone is Chatwall Sandstone
and whilst many quarries for this stone can still be found (none working)
the purple banding is rare. This quarry does however contain strata with
this banding.’ |
Mineralogy/Petrology |
|
0289 |
SO 412 851 |
High Wood (N) (Longville Plantation south) |
Quarry (disused) |
Ordovician: Caradoc: Chatwall Sandstone. |
Quarry cut into bottom of steep sided hill. |
The beds of Chatwall Sandstone dip gently to the SE and are generally quite
massive but with fossil lenses clearly visible at intervals up the section.
Some evidence of slickensides can be seen on loose material to the LHS;
fossils can also be found in this material. The bedding planes don't appear
to show as many features as those at Longville Plantation RIGS (SO410852).
The faces are partly obstructed by brash and waste plaster that has been
dumped. However the faces to the L are easily accessible. There is much
more loose material and some exposures extending about 100 m on the other
side of the stream. This site is presently used as a storage site but the
rock is still accessible behind. The talus shows some sedimentary features
and fossils but the structures of the exposures especially to the W end is
much less clear. |
Fork left in Cheney Longville past the castle and take the footpath that
goes NW over a stile and along the fields. The quarry is in the wood on the
right; off the path and through another gate. |
RIGS Yes. Combined with the existing RIGS in Longville Plantation
(SO410852). This is a large excavation with faces about 15 m high. It is
very accessible and big enough for large groups (especially if brash is
removed). It also seems more stable than the other quarry. A good example of
the lithology of and fossil coquinas within the Chatwall Sandstone of the
Ordovician. |
Fossils and Sedimentology/Stratigraphy |
|
0290 |
SO 412 861 on list (SO 411 861 in ref.1) |
Onny Valley |
Quarry (disused) |
Unconformity between Ordovician (Caradoc: Hoar Edge Grit) and Precambrian
(Longmyndian). |
Quarry cut into steep river bank. |
Exposure of the unconformity between the Ordovician and the Precambrian.
This is seen in a small weathered-out exposure at the top right of the
outcrop above the steps. The contact between the HEG and the weathered
sandstone of the Longmyndian can be made out. It is overhung by soil and
tree roots. The rest of this quarry is in HEG which has some good beds
showing current bedding and solution hollows in the more calcareous layers.
The beds dip steeply to the SE and their structure is very clear. |
This site is at the W end of the Onny Valley trail and is reached quickest
from the footpath that leaves the A489 at Glenburrell. However parking is
better at the other end of the trail in a car park off the Cheney Longville
road. |
RIGS Yes. Designated as part of a larger site encompassing the whole of the
river as outlined in the attached note (Word file name:- Onny Valley RIGS). |
Sedimentology/Stratigraphy |
|
0293 |
SO 413 859 |
Smeathen (ESE) |
Quarry (disused) |
Ordovician: Caradoc: Chatwall Sandstone. |
Quarry on top of the bank above the river. |
This quite a large (80 m x 50 m) but very shallow (2 m) quarry. There is
not much exposed in situ rock. Most of the surface is covered in loose
material which shows hummocky bedding; ripple marks and bioturbation. At
the S end there is a deeper pit which exposes steeply dipping; almost
vertical beds. They curve over towards the top which will be an affect of
faulting associated with the Church Stretton (F3) fault that runs just to
the E of this site. These beds are a continuation of those seen by the
Glenburrell railway bridge (413860). The rocks in the quarry are sandstones
and some siltstones. The quarry is quite grassy in places and there is some
rock which is alien to the site which has been dumped here. |
From the Onny Valley path go over the Glenburrell railway bridge. The
quarry is in the field to the left up the track just before it turns to
tarmac. Permission should be sort or the gate climbed. Alternatively it
can be reached down the track leaving the road NW of Cheney Longville at
GR412855. It is possible to park where the track turns to grass. |
RIGS Yes. Designated as part of a larger site encompassing the whole of the
river as outlined in the attached note (Word file name:- Onny Valley RIGS). |
Mineralogy/Petrology |
|
0301 |
SO 415 859 |
Horderley Quarries (Milestone) - Wistanstow |
Quarry (disused) |
Ordovician: Caradoc: Chatwall (Horderley) Sandstone. |
Quarry at base of hillside above main river valley. |
As per M. Allbutts report (RIGS report). This site is very overgrown in the
quarry back from the road and the brambles and scrub on the bank make it
difficult to reach. There is plenty of loose material within the quarry
which is fossiliferous and shows sedimentary structures. The roadside face
is still quite clear but could become overgrown. |
This site is on the N side of the A489 about 2 km west of the junction with
the A49. There is plenty of room to park on the wide verge in front of the
newly painted mile stone. |
RIGS Yes. Type locality for Horderley Sandstone; part of a large site taking
in the Onny Valley trail (see attached note). Reasons for designation: a)
ease of access to strata with a rich fossil content and good sedimentary
features with much use made by visiting local geological groups b) as a
major source of the distinctive local building stone. |
Mineralogy/Petrology |
|
0304 |
SO 419 849 |
Cheney Longvile (W) - Wistanstow |
Cutting (road/railway) |
Ordovician: Caradoc: Cheney Longville Flags. |
Road side exposure as road climbs steeply. |
The exposure at the above GR is badly weathered but this does help to pick
out different lithologies (different grades of sst and siltstone dipping
SE). There are some local distortion of dip at the top due to the affect of
tree roots. Changes are easy to see so would be good for a mapping or
logging exercise except it is on a nasty bend. There is some loose material
but not very much and no fossils were found in it on this visit. There are
more exposures all along the road up the hill; travelling west. These show a
variety of bedding thickness from <10 mm to 200 mm. (Don't mistake the dry
stone wall for outcrops!!). This must pass down through the series of
Cheney Longville flags and will include some alteranta Limestone (according
to the 1:25000 Craven arms map). A small shallow quarry is cut into the LHS
of the road near the brow of the hill (414853) which is in Chatwall
Sandstone. This shows flaggy sandstones again with no fossils being found
on this visit. |
These are all on the road heading west out of Cheney Longville. Park in
Cheney Longville where the road is wider; or in the gateway of Longville
Plantation at the top of the hill. All other facilities can be found in
Craven Arms. |
RIGS Yes. The first GR given is already designated as a RIGS mainly as the
de facto type section for upper Cheney Longville Flags. The whole of the
road from Cheney Longville west to the beginning of the Longville Plantation
is included in this designation. The road includes two stratotype localities
according to the list I have been given (418849 and 418851). It gives a
good section through the Cheney Longville Flags (including alternata
Limestone) and into Chatwall Sandstone. The east of the village it is
mapped as Acton Scott Group and if an exposure of this could be found on the
road it would extend the story further. |
Sedimentology/Stratigraphy |
|
0305 |
SO 418 857 (SO 418 856 in ref.1) |
River Onny (railway) |
Cutting (road/railway) |
Ordovician: Caradoc: Alternata Limestone |
Railway cutting. |
The exposure itself is obscured by vegetation but the structure (SE dip) and
lithologies (flaggy siltstone and micaceous sandstone along with the
limestone lenses) are still discernable. This is a very small exposure in a
shallow cutting of the old railway. There has been a sign here but this is
illegible and the post is no longer in the ground. There is still plenty of
loose material that shows fossils both as casts and still calcified. |
This can be reached either along the permissive path that follows the old
railway track from Cheney Longville car park along the footpath that leaves
the A489 at 417858 or from the other end of the permissive path that leaves
the A489 at Glenburrell. It is best to do the first of these as this is
where there is best parking. |
RIGS Yes. Designated as part of a larger site encompassing the whole of the
river as outlined in the attached note (Word file name:- Onny Valley RIGS). |
Fossils and Sedimentology/Stratigraphy |
|
0309 |
SO 421 855 |
River Onny (A) |
Cliff |
Ordovician: Caradoc: Acton Scott Group. |
River cliff cut on outside bend of meandering river. |
Here the beds of the Acton Scott group can be seen dipping 25°SE. They are
overlain by coarse river gravels. When the river has high flow (as it did
on this visit) it is impossible to reach the 5 m high cliff without waders.
It can be seen from the 'beach' just up stream but the structure is not very
apparent from this distance. Undercutting by the river has made the
overlying gravel fall to the river level and slightly obscure some of the
structure. Also at high water levels the 'beach' mentioned in ref.1 is
mostly covered. Some of the pebbles from upstream can be found including
some less worn ones which contained fossils. |
This is reached off the footpath that runs along the river and over a stile
in the fence that just serves to reach this locality. Park at the carpark
on the road to Cheney Longville. The footpath runs from here. |
RIGS Yes. Designated as part of a larger site encompassing the whole of the
river as outlined in the attached note (Word file name:- Onny Valley RIGS). |
Sedimentology/Stratigraphy |
|
0310 |
SO 421 857 |
Horderley Quarries (SE) - Wistanstow |
Quarry (disused) |
Ordovician: Caradoc: Chatwall (Horderley) Sandstone Alternata Limestone and
Chatwall Flags. |
Quarry cut into base of hill side above valley floor. |
As per report of M. Allbutt This area is becoming overgrown by brambles but
the main features can still be seen. The beds are breaking up at the soil
surface and some distortion has occurred as blocks have fallen out of the
face. The quarry off the road is vegetated with small trees and a lot of
ivy which is covering the faces. There are further small outcrops along the
road both to the west and the east of this site. |
This site is on the north side of the A489 about 1.5 km from its junction
with the A49. There is room to park on the verge and the faces are easily
accessible if a bit loose. All other facilities can be found in Craven
Arms. |
RIGS Yes. Incorporated into a large site taking in the Onny Valley trail
(see attached note). Designated as marking the transition from Ordovician
Chatwall Sandstones through the Alternata Limestone to Cheney Longville
Flags with good accessibility and all detail in situ. (the only other
comparable site is at Soudley Quarry) |
Sedimentology/Stratigraphy |
|
0338 |
SO 444 811 |
Norton Camp Wood |
Quarry (disused) |
Silurian: Ludlow Series: Aymestry Group |
Quarry cut into top of scarp slope. Gentler slope below of Lower Ludlow
Shales. |
Quarry runs for several hundred metres along the top of the scarp. Bedding
structure is easily seen in the flat faces trending N-S. Predominantly grey
crystalline nodular limestone separated by siltstone partings. Uneven
bedding at base of tallest face in sst. Some vertical jointing. Fossils to
be found in abundant talus. Ref.1 mentions A. reticularis; Spaerirhynchia;
Strophenella and C. knightii in various layers. Some calcite veining.
Brachiopods calcified and created solution hollows. |
Southernmost end easily accessible at junction of bridleway and footpath
from A49 at Lower Park. Otherwise accessible from footpath that runs along
top of scarp. Parking on lanes at start of footpaths or in Craven Arms.
All other facilities available in Craven Arms. |
RIGS Yes. Structure easily visible. Different lithologies noticeable
indicating different facies. Zoning of fossils (ref.1). Good access and
big enough for larger groups. Good for excercises such as logging. |
Fossils and Sedimentology/Stratigraphy |
|
0344 |
SO 447 822 |
Norton Camp Wood scarp |
Quarry |
Silurian: Ludlow Series: Lower Ludlow Shales or Aymestry Group. |
Excavated along track on scarp slope of ridge below earthworks. |
Quarry extending about 70 m along track; 4 m high. Well bedded lmst and
fine sst and sltst. Bedding structure more visible down track (S) than in
quarry itself. Some of the lmst very crinoidal (to N) more brachiopod rich
to S. Lots of talus containing various fossils. Further small exposure on
R of track-side continuing up the track towards the Camp. Could find
transition from Lower Ludlow Shales to Aymestry Group along this track with
further investigation? |
Easy access along footpaths from Craven Arms. All other facilities in
Craven Arms. |
RIGS Yes. Shows changes of dominant fossils in different layers. Structure
visible in places. Easily accessible on footpaths and would link with other
exposures such as quarry at 444811 |
Fossils and Sedimentology/Stratigraphy |
|
0354 |
SO 453 856 |
Moorwood Scarp - Strefford Wood |
Quarry |
Silurian: Wenlock Series: Tickwood Beds and Wenlock Limestone |
Series of quarries cut into top of scarp. View from this scarp to the higher
one formed by rocks of the Aymestry Group. |
Series of quarries running along the top of the prominent scarp just west of
Moorwood. Show the top of the Tickwood Beds and base of Wenlock Limestone
(ref.1). Largest is about 10 m high and 70 m long (to the R of Forestry
Commission sign); shows bands of nodular lmst separated by siltstone
partings less than 10 mm thick. Some layers show red staining. Some
jointing. Not obviously fossiliferous but some fossils can be found in
loose material. Smaller quarries (2 m high) lie to the L (SW) of the sign.
The beds here are thicker towards the base and there is a smaller proportion
of silly bands. More loose material with more abundant fossils. Good place
for a logging exercise. |
Easy access off Lower Dinchope to Westhope road at Moorwood. Parking in the
lane. Large area in front of main quarry if key for barrier can be
obtained. Vegetation makes access to the smaller quarries difficult. |
RIGS Yes. A good sized site with obvious structures (even to those who know
nothing of geology) and changes in lithologies. In combination with other
sites down the scarp it allows a good understanding of the rocks of the
Wenlock Series. Very easy access and the one large face is good for larger
groups. |
Structure and Sedimentology/Stratigraphy |
|
0376 |
SO 479 864 (also 482 863) |
Upper Westhope (S) |
Quarry (disused) |
Silurian: Ludlow Series: Aymestry Group |
Quarry cut into side of steep scarp slope. |
Quarry with a max height of about 10 m shows at the base well bedded
limestones lenses (20-50 mm thick continuing laterally for 2 m or more)
separated and surrounded by sltst (individual beds <10 mm thick). Some of
the lmst appears very fossiliferous but fossils are very broken (mostly
crinoids?). Lmst becomes more nodular higher up the section but is still
the dominant lithology. Towards the top siltstone becomes dominant with
beds of fine sst. The top beds of the section are inaccessible due to the
steepness of the faces. The easterly dip means a lot of different beds are
accessible at the foot of the faces. There is some loose material; more may
be found beneath the brambles and other vegetation. A good site for
exercises such as logging. |
Accessible along bridleway from Westhope village next to a good sized
carpark (476862). The walk along here takes about 15 mins. |
RIGS Yes. Good structure with change in lithologies throughout the section.
Dip means lots of beds are easily accessible. Easy access with relatively
parking nearby. Fossils can be found. |
Fossils and Sedimentology/Stratigraphy |
|
0413 |
SO 274 981 |
Whittery Quarry - Chirbury |
Quarry (disused) |
Ordovician: Caradoc: Whittery Volcanics and Shales (ref.1). |
Quarry is cut into the top of the steep sided Marrington Dingle which has
been cut down by the River Camlad. |
The main feature of this quarry is the contact between the volcanics and the
shales; can be appreciated from a distance. The shales are thinly bedded
and lie above the much more massive units of the volcanics. The quite steep
westerly dip of the beds can be seen in the shales at the far LH side of the
quarry. Here they can be seen to fold under the overhang created by tree
roots. The volcanics are seen along the strike and there was a constant
leak of water out of the rock presumably following the bedding surfaces.
There are a few other small outcrops of the shales and volcanics around the
quarry but most of it is fully vegetated. The main face has kept clear due
to the steepness at which it was cut. |
From Chirbury take a small lane just SE of the village off the A490 towards
Hagley. Follow this up a steep hill and round a sharp bend. The quarry is
below the road (W) just after a small gap in the woodland on this side.
Park in the nearby enlarged gateways and follow the footpaths down to the
site. One path leaves the road to the N of the quarry the steep faces of
which are not fenced off from it so care must be taken! |
RIGS Yes. Cear demonstration of the conformable nature of the volcanics and
the shales. This site is FULL of rubbish which makes access to most of the
main face impossible. Steep loose banks make access to the rest very
difficult. However despite the rubbish that makes close inspection
impossible there is plenty to be gained from a distant look. (also see new
report in addeenda section below) |
Sedimentology/Stratigraphy |
|
0508 |
SO 356 998 |
Bergams Corner - Worthen and Shelve |
Quarry (disused) |
Ordovician: Shelve Group: Mytton Flags and intrusive dolerite. |
On bend in road with views north to North Shropshire Plain and closer to
steep valley sides e.g. Mytton Dingle (due to faulting?). |
This quarry face about 15 m high predominantly consisting of very dark
Mytton Flags. However in the extreme top right corner is the dolerite
intrusion as marked on BGS Shelve Ordovician Inlier map (1:25000). This is
a much stronger rock and has weathered to a brown colour. The loose
material it produces looks slightly different to that produced by the Mytton
Flags. The face is very steep and covered in loose scree which makes
reaching the top difficult but the difference in lithology can just about be
made out from the lay-by. The sedimentary rock here does not appear to
contain any obvious fossils. |
It is on the inside of a tight right hand bend between Tankerville and
Stiperstones Village. There is plenty of space to park in front of the
exposure. Other facilities can be found in Stiperstones Village. |
RIGS Yes. This has also been designated as an SSSI and as the rock is still
clear and easily accessible. |
Sedimentology/Stratigraphy |
|
0702 |
SO 328 841 |
Bury Ditches (N) |
Quarry (disused) |
Silurian: Ludlow Series (undivided) (BGS Wales Map 1:250000) |
Large quarry near the top of Sunny Hill from which there are good 360° views
interpreted with the aid of a toposcope. |
The face in Ludlow Series is quite impressive but difficult to reach due to
the vegetation. It is about 20 m high at the maximum and about 50 m wide.
It displays well bedded siltstone and fine sandstone with a gentle dip. The
beds are of quite regular thickness being 30 to 50 mm thick and the whole
exposure looks quite uniform. Due to the steepness of the face and the
angle of the dip only a limited number of beds can be reached to see if this
is really the case. The safest and easiest bit to reach is to the right of
the entrance where it is only a few meters high and there are no dangerous
overhangs. A few fossils were found in the loose material in this area.
There is little loose material visible elsewhere but there is probably quite
a bit under the leaves and fallen branches. |
This is on the green way-marked route through the forest. Park at the
Forestry Commission carpark for Bury Ditches and take the main path up and
through the hill fort. Over the other side take the right hand track at a
T-junction. This track then passes the quarry entrance. |
RIGS Yes. This is a large but very vegetated quarry on the N slope of the
hill. Considered as a RIGS in conjunction with other sites in the Bury
Ditches area that show the different facies of this part of the Ludlow
Series. |
Mineralogy/Petrology |
|
0707 |
SO 504 745 and SO 506 744 to 512 741 |
Whitcliffe (W) and Teme Bank |
Quarry (disused) |
Silurian: Ludlow Series: Whitcliffe Beds. |
Huge quarry cut into hillside towards the top of Whitcliffe plus excavations
for the Bread Walk footpath just above the river. |
A series of small rock faces along the Bread Walk (max height generally 2 m)
show well bedded sltst with some more calcareous layers. Beds 10-100 mm
thick gently dipping to NW. Some internal bedding visible. Most of the
loose material contained fossils in thin layers which included many genera
of brachiopods; bivalves; bryazoans and ostracods. Some of the fossil
layers were visible in the rock faces. Along the River Teme bank and up
Whitcliffe there are a number of exposures and larger quarry faces along all
the upper paths through the wood and along the river. These show structures
such as solution hollows; current bedding; fossil lenses; spheroidal
weathering; bioturbation. Lithologies vary in the different layers which
range from fine friable siltstones to fine sandstones and calcareous
sandstone and siltstone. Bedding thickness range from mm scale to 500 mm.
Dips indicate a slight anticlinal structure with beds dipping NW at the west
end of Whitcliffe and East at the east end. The largest single exposure is
in the main quarry, just above the rock-cut steps in the Bread Walk. This
extends for ca. 200 m along a small path and the main face is about 15 m
high. The path goes uphill slightly allowing several of the beds to be
examined closely. This is also a good source of fossiliferous debris
showing brachiopods; crinoids and occasional in-filled burrows. The higher
exposures are unsafe and small rockfalls frequently occur, expecially after
frost thaws. |
Parking along the road leading to Mortimer Forest and the higher ground
above Whitcliffe. |
RIGS Yes. Easy access to the higher beds in the sequence which may not be
visible elsewhere. |
Sedimentology/Stratigraphy |
|
0710 |
SO 394 875 |
Hillend Cottage (E) - Lydbury North |
Natural exposure |
Silurian: Llandovery Series (Upper): Pentamerus Beds. |
Small exposure off road at base of hillside. |
This is a good exposure of Pentamerus Beds dipping quite steeply SE which
shows the fossil bands very clearly especially near the bottom of the
outcrop and another about 1.6 m up the section. It also shows the other
lithologies in these beds. The fossils are still predominantly calcified.
There is plenty of fossiliferous loose material. Also in the talus were
other rock types including grey sandstone with calcite veins; and a few
pieces of hard; purple slate-like shale. It shows a much clearer structure
than a lot of the other sites along this road including the SSSI (Hillend)
about 300 m E. |
Park at the lay-by about 400 m SW of this exposure. The outcrop is just up a
track on the N side of the A489 over a derelict wooden gate. The exposure
can be seen quite clearly from the road. |
RIGS Yes. Shows clearly the structure of the rocks and the fossils that give
this rock its name (Pentamerus Beds). It has easy access and plenty of loose
material to study. |
Fossils |
|
0713 |
SO 420 854 |
Onny Valley (old river cliff) - Wistanstow |
Cliff |
Ordovician: Caradoc: Cheney Longville Flags. |
Old river cliff; about 50 m away from present river line. |
Well bedded Cheney Longville Flags containing fossils such as tentaculites
and brachiopods and bedding features such as hummocky bedding. The bottom
section can be reached around the back of the bog which wasn't too wet at
the time of this visit. However this area has a few dangerous overhangs.
The other area is above the first up the farm track. Here the exposure is
not so good but it is safer. There is more loose material on the farm track
than below where it has probably sunk into the bog; but there is more
vegetation at the top. The different lithologies (sltst; sst and mudstone)
can be seen in either area. |
This is just off the permissive footpath that runs along the valley. It is
on the N side and is reached over a stile in the fence off the old railway
track. It is best to park in the car park on the Cheney Longville road
(SO428845) and walk along the river. |
RIGS Yes. This exposure is found to the N of the railway line behind a boggy
patch of ground. Designated as part of a larger site encompassing the whole
of the river as outlined in the attached note (Word file name:- Onny Valley
RIGS). |
Fossils and Sedimentology/Stratigraphy |
|
0714 |
SO 417 857 |
River Onny (railway) |
Cutting (road/railway) |
Ordovician: Caradoc: Chatwall Sandstone (highest). |
Old railway cutting. |
This site is right on the side of the old railway and as it is only a few
metres high it is all easy to reach. There are local variations in dip but
all beds are dipping to the SE. Shell bands can be seen in the in situ rock
and there are plenty of fossils in the loose material. It is suggested that
the change in dip is due to changing storm conditions (ref.1). |
This is along the permissive path that follows the old Bishops Castle
Railway line from a carpark west of Cheney Longville to Glenburrell.
Therefore this site can be approached from either end but parking is much
better at the E end. |
RIGS Yes. Designated as part of a larger site encompassing the whole of the
river as outlined in the attached note (Word file name:- Onny Valley RIGS). |
Fossils and Sedimentology/Stratigraphy |
|
0715 |
SO 413 860 |
Glenburrell railway bridge |
Cutting (road/railway) |
Ordovician: Caradoc: Chatwall Sandstone. |
Cutting on S side of old railway track running along side the river. |
A long (50 m) exposure which is on the W side of the Church Stretton (F3)
fault. The faulting is responsible for the steep dip (85°SE) at this
locality compared to about almost horizontal bedding that is seen a few
hundred meters further east. In these mainly medium grained sandstone beds
some structures are visible such as current bedding indicative of storm
conditions. This is a good exposure with easy and safe access. There is a
further exposure of Chatwall Sandstone that shows the typical purple banding
better (Locality 3 in ref.1). This is found to the E up the bank in the
trees; however it is not easily accessible. Under the railway bridge there
are small stalactites made from water percolating through the mortar of the
bridge. |
This is along the permissive path that follows the old Bishops Castle
Railway line from a car park west of Cheney Longville to Glenburrell.
Therefore this site can be approached from either end but parking is much
better at the E end. |
RIGS Yes. Designated as part of a larger site encompassing the whole of the
river as outlined in the attached note (Word file name:- Onny Valley RIGS). |
Sedimentology/Stratigraphy |
|
0800 |
SJ 553 035 to SJ 559 036 |
Coundmoor Track - Cound |
Track/roadside |
Main exposure is Precambrian (Uriconian Volcanics) but there are small
exposures of Ordovician (Hoar Edge Grit and Harnage Shale; Caradoc Series)
and what appears to be Lower Ordovician (Sheinton Shale; Tremadoc). |
Exposure of Precambrian forms a small bluff along the track while the others
are trackside exposures in a wooded valley drained by the Coundmoor brook. |
Main exposure of Uriconian Volcanics is generally rhyolitic with some more
basic rock. The rock is badly weathered and rotten with evidence of being
broken by faulting. On the right of the exposure the rock looks as if it is
bedded vertically but this is probably the result of faulting and it is part
of a shear zone. Here; there is considerable hematite staining. The exposure
continues above the main face for another 2-3 m but the rock is covered with
ivy and no detail can be seen. Along the track towards Cound (Eastward);
Hoar Edge Grit is exposed and near the foot bridge and confluence (SJ
559036) there is a good exposure of a different; probably Sheinton Shale. |
Track becomes a public footpath a few metres beyond the Uriconian Volcanics
exposure. Access is easy and one can examine the rocks close at hand.
Parking is limited to two cars at the ford (SJ553034). |
RIGS Yes. Designated a RIGS on account of its vivid demonstration of the
effect of the Church Stretton fault system in bringing into juxtaposition
many rock units of different age and lithology. |
Structure and Stratigraphy/Stratigraphy |
|
0803 |
SJ 558 034 to 559 037 |
Coundmoor Brook - Cound |
Stream/brook |
Upper Ordovician: Caradoc Series: Harnage Shale. |
Brook meanders along a narrow valley then through woodland. |
There are several bank exposures of Harnage Shale and some in the stream
bed. At the W end of the SSSI; about 40 m from an old bridge built of Hoar
Edge Grit; is a bankside exposure of grey shale; water seeps out and flows
over it as a small waterfall. The shale is finely laminated; soft and shows
vertical and over-turned bedding. A few metres away the dip has lessened to
approx. 40°. There is evidence of brecciation. All this points to effects of
the Church Stretton fault system. Upstream 100 m is another shale exposure
under the roots of an oak tree; which can be seen crossing the bed of the
brook. Here the dip is 54° NW. The SSSI continues further downstream and
exposures in the stream bed were examined at SJ 559037 where the Harnage
Shale is still outcropping. Here the beds can be seen dipping below water
level and are best examined by wading along the brook. |
Easy access from the public footpath. Limited parking at the ford
(SJ553034). Otherwise approach from Cound Church. |
RIGS Yes. This is a nationally important geological site providing exposures
of fossiliferous rock of Ordovician age. The stream exposures are regarded
as the standard or type-section for the Harnagian stage of the Ordovician.
During this stage; this area lay on the eastern edge of a deep ocean basin
covering Wales while shallower shelf environments lay to the east. Fossil
organisms characteristic of both environments are found at this site;
allowing detailed comparisons to be made. In addition; a number of species
of trilobites were first collected and described from this locality. |
Fossils and Sedimentology/Stratigraphy |
|
0805 |
SJ 604 082 |
Rushton - Wroxeter |
Track/roadside |
Precambrian: Rushton Schists. Special Sheet 60 - Telford. |
Not applicable. Exposure is a small flat feature on the level ground in
Rushton village about a kilometre from the Wrekin. |
Exposures of Rushton Schists are rare and this one is revealed by erosion
and weathering. The amount of rock visible is limited to an irregular
surface outcrop. A finely laminated fine-grained dark olive-grey schist is
visible with quartz; plagioclase and chlorite. Foliations can be seen. This
is inter-bedded with more massive; pink; quartz- feldspar rocks which are
said to contain garnet and epidote. There is evidence of quartz veining.
These rocks were originally gritty shales and flags deposited in quiet
waters and subsequently regionally metamorphosed to a low/medium grade.
Compared by Dearnley to the Mona Complex of Anglesey. |
Public road. |
RIGS Yes. Although a limited site; it is one of very few easily accessible
Rushton Schists exposures. As one can examine the rock readily and as these
represent the oldest rocks of Shropshire. |
Mineralogy/Petrology |
|
0807 |
SJ 608 001 to 609 000 |
Wenlock Edge (N) (Edgefield Quarry) |
Quarry (disused) |
Silurian: Wenlock Limestone (reef facies). Special Sheet 60 - Telford. |
Forms a gorge cutting across the crest of Wenlock Edge. |
This is an excellent site; a large disused quarry displaying a range of reef
features in the context of surrounding bedded limestone. Next to the
footpath there is a prominent exposure of nodular limestone with slabs of
near horizontal limestone projecting from it. Height of face here approx. 8
m. To the left (SE); nodular limestone passes into more regular bedded rock
with clay partings. The limestone is coarsely crystalline; often crinoidal;
and examination of the fallen fragments revealed compound corals; small
brachiopods and bryozoa. The exposure continues for about 200 m being
accessible by a path along the gorge. At the far end there is a magnificent
face showing ballstones inter-bedded with nodular and flaggy limestones.
Thin beds can be seen above and dipping off the ballstone mass. A recess 2 m
from the bottom marks a clay layer; possibly bentonite. Great limestone
slabs overhang at the top of the face which is here about 10 m high. |
Via public footpath from Harley Hill or Much Wenlock. |
RIGS Yes. RIGS on the grounds of the range of features characteristic of the
Wenlock Reef Facies; the easy access; its potential educational value; and
the impressive beauty of the site. |
Fossils and Sedimentology/Stratigraphy |
|
0808 |
SJ 6100 0035 |
Harley Hill Quarry - Much Wenlock |
Cutting (road/railway) |
Silurian: Wenlock Series: Tickwood Beds (Special Sheet 60 - Telford); now
known as the Farley Member. These are beds transitional between
Coalbrookdale Formation and Much Wenlock Formation. |
Site is part of an impressive road cutting where the A458 goes through the
escarpment of Wenlock Edge. |
The section comprises 15-25 m of grey; shaly mudstones with numerous
prominent limestone nodules often forming bands. Fossils were not easy to
find despite written references to the presence of large brachiopods; e.g.
Eospirifer radiatus and Meristina obtusa (which suggest the sea was
shallower than in Coalbrookdale Formation times; thus emphasising the
transitional nature of the rocks at this site). There are several prominent
vertical joints and two distinct recessed clay horizons near the base of the
section. These weather to a brownish colour and are probably bentonite
layers. Towards the west end of the quarry the bentonite layers are
displaced by approx 3 m by what appears to be a fault. The lower part of the
face has fewer nodules and beds are more irregular. Ascending the sequence;
the nodules become more calcareous and begin to 'fuse' into definite layers.
This is an indication that the conditions were becoming more suitable for
limestone formation and the Farley Member passes upward into the Much
Wenlock Formation. It is written that the lower boundary of the latter is
located where calcareous nodules coalesce into limestone beds. It is not
easy to locate this boundary with conviction. |
This site is next to an extremely busy road and to approach on foot can be
hazardous. Not to be recommended for large groups or school parties.
Parking is very limited; there being two places where a single car might
pull in. |
RIGS Yes. This is clearly an interesting and important site and although its
importance has been reduced a little by the newer Farley Dingle road
cutting; it still shows very effectively the characteristics of the
transitional Farley Member of the Wenlock Series. |
Sedimentology/Stratigraphy |
|
0817 |
SJ 624 008 |
Windmill Hill - Much Wenlock |
Quarry (disused) |
Silurian: Wenlock Limestone. Special Sheet 60 - Telford. |
At the base of a hill with remains of old windmill. Hill is a prominent
landmark in the town. |
Rocks exposed here are bedded Wenlock Limestones; mostly crinoidal. The
faces are to some extent obscured by weathering but display clearly both
nodular and flaggy beds. A definite recessed softer horizon is emphasised by
differential weathering. This is clayey in character. Bedding planes appear
to be wavy as a result of the nodules and dip generally NW. In the NW corner
is a prominent fault or joint plane (not easy to decide which) with tufa
deposits. The quarry provides good examples of true and apparent dip.
Height of exposure is 3-4 m and the width of the quarry is approx. 20 m. On
the ground were rock fragments containing a range of typical reef facies
fossils e.g. Favosites gothlandicus; Heliolites interstinctus; Acervularia
ananas; and various brachiopods. Some evidence of stromotoporoids as well
as crinoids was found; and on the back face possible striations were seen.
There is a distinct boundary at the bottom of the back face which seems to
mark the change from reef facies to more bedded limestone. |
Good. Next to public footpath close to the town where there is
car-parking.. |
RIGS Yes. RIGS mainly because it is a convenient site for school or
university groups to examine easily both the reef facies of Wenlock
Limestone and the bedded limestone; collect fossil material and carry out
dip and strike exercises as well as identifying structures and evidence of
calcite mineralisation. |
Sedimentology/Stratigraphy |
|
0820 |
SJ 627 079 |
Wrekin Hill |
Natural exposure |
Mostly Precambrian (Uriconian Volcanics) with Cambrian (Wrekin Quartzite) on
the SE flanks. (Special Sheet 60 - Telford.) |
The Wrekin Hill stands prominently out of the surrounding plain to a height
of 407 m. Striking towering mass of rhyolite with a deep cleft |
Apart from the summit rhyolites the exposures although numerous are small
but there is a wide variety of Uriconian tuffs agglomerates and rhyolites
which can be examined easily. The summit rhyolites are pink; often
flow-banded and sometimes spherulitic.The Needle's Eye is one of several
rhyolite outcrops on the summit ridge of the Wrekin. The rhyolites are
heavily brecciated and fragmented; described as explosion breccias; formed
during violent volcanic events. This makes up part of the series of rhyolite
flows forming the central mass of the Wrekin. The rock of the Needle's Eye
is described by Pocock as a rhyolite 'devitrified to a micro-felsitic
intergrowth of quartz and feldspar; with incipient spherulitic structures'.
It is veined with secondary silica. The rock at the Raven's Bowl and Bladder
Stone is probably from the same flow. At the Needle's Eye there is little
flow-banding; instead the rhyolites show characteristics of auto-brecciation
(a clear indication of the explosive nature of the volcanic environment).
Elsewhere many basic dykes are visible along the main route to the top. At
the foot of the Wrekin; and along the main path several exposures of tuffs
and Cambrian quartzite are exposed. Up to 1500 m of tuffs and lavas occur on
the Wrekin and the rocks are considered to have originated during a
prolonged episode of explosive volcanic activity in an island arc
environment in the Late Precambrian. |
Open access. |
RIGS Yes. RIGS status in its own right as well as being part of the whole
Wrekin RIGS site. The rhyolites can be examined easily and compared with
other rhyolites and tuffs of the summit area. However it may be decided that
designation of the Wrekin in its entirety is sufficient. Designated a RIGS
as the type section for the Uriconian volcanic suite of lavas an
pyroclastics and associated with the Ercall and Lawrence Hill as an
outstanding example of a faulted inlier. It is a unique location where a
range of Precambrian lavas and pyroclastics can be easily studied. In
association with the Ercall and Lawrence Hill; the Wrekin provides an
outstanding example of a faulted inlier of Precambrian igneous rocks. |
Mineralogy/Petrology |
|
0827 |
SJ 638 093 |
Lawrence Hill (Forest Glen) Quarrry |
Quarry (disused) |
Precambrian: Uriconian Volcanics. Special Sheet 60 - Telford. |
Spectacular cliff in the Forest Glen between Wrekin and Ercall Hills. |
The quarry lies to the south end of the Ercall and Lawrence Hills opposite
the Wrekin. It consists of two embayments separated by three near-vertical
NE/SW- trending dykes of basalt which appear to follow faults. The middle
dyke is most easily examined and forms a prominent rib. The contact with
surrounding pyroclastic rocks is visible. The main face consists of
Precambrian tuffs and agglomerates belonging to the Uriconian Volcanics and
these are seen to dip approx N at an angle of 45°. The tuffs display
variable textures with definite coarser agglomerates inter-bedded with
lithic and vitric rhyolitic tuffs. Irregular jointing and slickensiding
characterise the quarry faces. |
Open access as the site backs onto a car park on the road through Forest
Glen from Wellington to Little Wenlock. |
RIGS Yes. RIGS as an exemplary exposure of a sequence of Precambrian
volcanic tuffs (and lava) which merits classification as a type section for
that strata and which would be an essential exposure in any future research
carried out on Precambrian volcanic rocks. |
Mineralogy/Petrology |
|
0832 |
SJ 665 058 |
Jiggers Bank - Coalbrookdale |
Cliff |
Upper Carboniferous: Lower Coal Measures. Special Sheet 60 - Telford. |
Part of the steep side of Coalbrookdale as it descends into the Ironbridge
Gorge. |
An impressive exposure of mostly Carboniferous sandstone; grey/buff
weathering orange; which has some massive bedding showing
cross-stratification. This distinctive layer is at the top of the section
and is about 6-7 m thick. The base of this horizon is a coarse conglomerate.
In places there is a projecting overhang below which is a more flaggy;
thinner layer (1.5 m) of sandstone. This passes downward into a more broken
sandstone layer before passing into grey; laminated sandy shale containing
many carbonaceous fragments. The dip can be clearly seen to be approx. NNE.
By walking a few metres along the Crackshall footpath a continuation of the
exposure can be seen and examined. This is hidden by trees in summer. The
rocks here are representative of a poorly drained delta plain. |
Site is readily accessible as it lies beside a public footpath. Limited
parking is possible about 200 m down the hill but the walk to the site is
along a busy road; Jigger's Bank. |
RIGS Yes. A very good exposure of Lower Coal Measures; illustrating
variation in sedimentation according to changing environmental conditions
within a deltaic setting. A striking example with reasonable access. |
Sedimentology/Stratigraphy |
|
0834 |
SJ 675 068 |
Doseley Quarry |
Quarry (disused) |
Lower Carboniferous: Dinantian: Little Wenlock Basalt. Special Sheet 60 -
Telford. |
Forms the back wall of an infilled and partly flooded old quarry; in the
middle of Doseley. |
Basaltic columns rise to approx.12-14 m behind a pool; forming the back wall
of the old quarry. Strong horizontal joints cross each of the columns.
Between the columns orange soil of weathered basalt is visible and to the
right; a deep red ochre can be seen where the iron minerals have weathered
out. To the right of the main face are two thick beds of overlying Coal
Measure Sandstone resting unconformably on the basalt; dipping NE. Near to
the reception offices beside the track there are exposures of leaning
columns and excellent examples of spheroidal weathering. These can be
examined at close hand. |
Cannot approach the columns of basalt on the back wall of the quarry |
RIGS Yes. This is probably the best example in the County of the Little
Wenlock Basalt showing columnar structures. It is already an SSSI. |
Mineralogy/Petrology |
|
0838 |
SJ 683 117 |
New Hadley Brickpit |
Quarry (working) |
Carboniferous: Upper Coal Measures: Hadley Formation. |
Changes according to the current work in the pit. |
The site is a face within the working clay pit. Its thickness is approx. 34
m but not all is readily visible. The rock is Etruria-type mudstone; with
espleys. The mudstone is mainly purple-brown; unbedded and in places
mottled. The espleys are easy to identify; being best described as a fine
breccia with angular fragments of Uriconian igneous material; feldspar; Coal
Measures sandstone; and shale clasts in a matrix of angular coarse sand.
Sharp erosional bases can be seen cutting into the underlying mudstone;
reflecting channelling by flood waters from a relatively close upland
source. Espleys are therefore lenticular channel-fill deposits; 30-40 m wide
and commonly aligned NW/SE. Overlying the Hadley Formation are the grey
mudstones representing the seat earth of the Main Sulphur Coal. |
Via reception area at Blockley's with prior permission. |
RIGS Yes. The sediments here are representative of alluvial fans at the
margin of the basin of deposition. Such marginal deposits in the Hadley
Formation are virtually confined to this area and this is the only site
where they can be clearly demonstrated. A site of outstanding importance for
interpreting the geological history of the Late Carboniferous in Britain. |
Sedimentology/Stratigraphy |
|
0840 |
SJ 690 023 |
Corbetts Dingle - Broseley |
Natural exposure |
Upper Carboniferous: Upper Coal Measures: Coalport Formation. Special Sheet
60 - Telford. |
Gorge-like valley eroded along the Corbett Fault. |
Impressive exposure of mainly sandstones either side of a deeply cut brook.
The grey-buff sandstones tower 12 m or so above the footpath and display
abundant cross-stratification and spheroidally weathered iron-rich nodules.
The sandstones are exposed for about 300 m along the main dingle but there
are more in the tributary valley. It is therefore a large site and would
benefit from more detailed study. Some beds are massive; up to one metre
thick; while others are more flaggy. Dip of strata is about 18° NW but the
effect of the fault steepens the dip; especially in the tributary valley.
Faulting has caused a downthrow and displacement of sandstones and breccia
beds of 10 m to the west. |
A public footpath follows the dingle and close up examination of the site
can be carried out. Approach either from The Tuckies by R. Severn or from
the Ironbridge road; Broseley. |
RIGS Yes. Splendid site with much educational value on account of its being
able to accommodate a large group and be easy of access. The sandstones with
many sedimentary structures representing part of the Coalport Formation and
the excellent example of a fault-guided valley present a strong case for
RIGS. |
Structure and Sedimentology/Stratigraphy |
|
0842 |
SO 728 934 |
The Hermitage - Bridgnorth |
Quarry (disused) |
Permian (Bridgnorth Sandstone) and Lower Triassic (Kidderminster
Conglomerate). Dudley and Bridgnorth 1967. New names from Telford Sheet. |
Recessed cliff with evidence of cave habitation. The conglomerate forms roof
of medieval (?) dwelling. |
This is a striking exposure of the wind-blown Bridgnorth Sandstone with its
clear cross-bedded units reflecting a desert environment. It is possible to
reach the face to examine the texture of the millet-seed and grains and the
nature of the dune bedding. The rock is uniformly fine-grained and red-brown
in colour. Cement is scanty and although the rock stands up well as a cliff
face it crumbles readily. Dip of beds is about 7° E. The Kidderminster
Conglomerate has large rather angular clasts of Carboniferous Limestone marl
and quartzite with scattered pebbles of igneous origin held in a coarse
sandy matrix (Dudley & Bridgnorth Memoir; 1947). This represents the basal
unit of the Lower Triassic. Deposited by a major north-flowing river system
during flash floods in a semi-arid climate. It rests unconformably on an
eroded Permian surface. Queen's Parlour on Wolverhampton Road is directly
adjacent to The Hermitage. The exposure is some 50 metres long by 15 metres
high. The base of this exposure comprises the Lower Mottled Sandstone (5 to
6 m deep) - a medium to fine grained rock displaying some dune bedding and
believed to have been lain down in aeolian conditions. This is overlain by
the Bunter Pebble Beds ( 7 to 8 m deep) consisting of a conglomerate
composed of angular and subrounded pebbles (30 to 40 mm). The Bunter Pebble
Beds are considered fluviatile in origin and the contents vary. |
Via steps and footpath from A454. Some barbed-wire obstacles. After about 1
mile there is a small traffic island and some 50 m from the Bridgnorth side
of the Island on the left hand side of the road there is a small `pull in'
suitable for possibly two vehicles. From there retrace route back towards
Bridgnorth via a footpath along the side of the road. After about 200 m an
exposure of conglomerates is clearly evident. About 20 m below this
exposure and on the other side of the road a footpath sign is just visible.
Cross the road and take a well trodden footpath which after about 30 m will
lead to a sandstone and conglomerate exposure. This is The Hermitage and is
adjacent and to the right of the Queen's Parlour. Access is reasonable.
However the crossing of the main Wolverhampton Road at this point is not for
the faint hearted. It is a short and easy walk to the outcrop from the main
road. |
RIGS Yes. Spectacular example of an erosion surface in the upper part of the
Bridgnorth Sandstone overlain by Kidderminster conglomerate. Shows clear
evidence of changing environment from desert to flash floods. |
Sedimentology/Stratigraphy |
|
0843 |
SO 727 935 |
Hermitage Hill - Worfield |
Cutting (road/railway) |
Permian (Bridgnorth Sandstone) and Lower Triassic (Kidderminster
Conglomerate). Bridgnorth and Dudley map 167. |
A454 road cuts through the rock exposing strata each side. |
A small exposure of Bridgnorth Sandstone at the western end of the cutting
passes into a good section through the Kidderminster Conglomerate. Large
pebbles of quartzite Carboniferous Limestone marl and igneous rocks are held
in a sandy matrix made stronger by a calcite or silica cement. Evidence of
alignment and cross-stratification can be seen. The clasts become less
continuous higher up when the proportion of sand (fine and less bright than
the Bridgnorth Sandstone) increases. Pebbles scattered in approximate layers
and more randomly (smaller); cross-stratification in the sandstone;
generally agreed to be fluvial. An interesting feature is the good example
of channelling towards the E. end of the cutting and high up in the face. |
Exposure is on a main road but there is a footpath. Traffic noisy and
dangerous. |
RIGS Yes. Despite the main road this site is valuable when studied with
SO728934 (The Hermitage). It is higher in the sequence and although a
little Bridgnorth Sandstone is visible the main interest lies in the
Kidderminster Conglomerate which passes upwards from being coarsely
conglomeratic into fluvial sandstones with evidence of channelling. |
Sedimentology/Stratigraphy |
|
0845 |
SJ 539 143 (fence of quarry moved; exact position difficult) |
Haughmond Hill (W) - Uffington |
Natural exposure |
Precambrian: Wentnor Group: Bayston-Oakswood Formation: Darnford
Conglomerate. Sheet 152. |
On west slope of Haughmond Hill near the top. |
Southwest of the main working quarry; beyond the perimeter fence are several
small exposures of Darnford Conglomerate showing orientation of pebbles
parallel to the vertical dip. By the footpath which runs along the west
boundary of the working quarry are more small exposures. Pebbles are often
very small (2 mm) but there are coarser bands with pebble up to 10 mm
across. The N-S orientation of the pebbles reflects the same trend of the
strata which are always nearly vertical. Some quartz mineralisation was seen
on the surface and structures resembling slickensides. A little further
north a wall-like exposure can be seen; 3 m across and one metre high.
Although it at first looks artificial; on closer examination it appears to
be a vertical exposure of very coarse; poorly sorted grit with a variety of
clasts; some being green and others black. This reflects the presence of
iron minerals and chlorite; mentioned by Pocock. This exposure is crossed by
regular joints at right angles to each other and appears to consist of
rectilinear blocks about 0.1 m across. This seems to mark the boundary
between the grits and conglomerate; the latter being exposed only a few
metres away along the footpath. |
Mostly along a public footpath but the grit exposure is just the other side
of the perimeter fence. |
RIGS Yes. Designation because this is a striking example of the coarse grit
adjacent to the Darnford Conglomerate; both being conformable members of the
Bayston-Oakswood Formation. The boundary between the two rock types seems
to be here and the site can be reached without going into the main quarry.
Also these exposures should be seen in the context of the geology of the
whole of Haughmond Hill. |
Mineralogy/Petrology |
|
0848 |
SJ 275 252 |
Sweeney Fen |
Cutting (road/railway) |
Lower Carboniferous: Sandy Limestone. Sheet 137. |
In a cutting through the rolling country SW of Oswestry. A glacially
modified landscape. |
Exposure is up to 30 m long and 5 m high. It is most clearly examined at the
S end of the cutting. Thick beds of red sandstone (1 m) are exposed here
showing cross-bedding in contrast to the true dip. Scattered small pebbles
occur parallel to the cross-bedding within the thicker strata and also a 40
mm layer of larger; mostly quartz pebbles is seen parallel to the true
bedding. These pebbles are white and pink; avr. 30 mm long being
well-rounded and densely packed. The sandstone is soft; iron-rich and with
little cement. About 1.5 m above the base truncation of topset beds can be
seen. Joints are common and break up the face in places. Dip is 15° NNE. |
Beside public right of way. Easier from southern end because some awkward
fencing at northern end of cutting. |
RIGS Yes. Designation because this shows the contrast between
cross-stratification and true dip in sandstones which form a transition
between Limestones and the Millstone grit of the L. and U. Carboniferous.
Wedd speaks of the Sandy Limestone in the south of its outcrop; where it
approaches the Triassic rocks as being decalcified and bright red. This
description fitted the exposure at this site and it was considered that this
site provided a good example of this rock formation. Hillier raises
uncertainty regarding the age of these rocks possibly being of the Cefn-yr-Fedw
Sandstone and thus Namurian rather than Dinantian. All adds to the interest
of this site. |
Sedimentology/Stratigraphy |
|
0851 |
SJ 277 245 |
Dolgoch Quarry |
Quarry (disused) |
Lower Carboniferous Limestone; Sheet 137. |
Part of the hilly Carboniferous Limestone escarpment SW of Oswestry. |
A very impressive quarry on a large scale. The limestone dips NE at about
12°. There are excellent clear faces up to 10 m high on two sides of the
quarry; bedding is well-defined and approx. 2.5 m from the top is a recess
of clay and shaly material. In the middle of the face is a massive bed 2 m
thick and below are layers showing signs of bioturbation and quite high
energy stirring up of sediment. In this layer are found many fossils; as
death assemblages; notably Giganto-productus and the coral Lithostrotion
junceum. At the foot of the face are several strata more regularly bedded.
The succession here is typical of a very shallow tropical sea. Variation in
texture and colour of the different beds of limestone can be examined but
most of the rock is light grey and crystalline. Some calcite mineralisation
is evident and often associated with slickensiding and faulting. A fine
example of faulting is seen on the west face; showing a displacement of
about a metre. Other striking features are the load casts; two particularly
fine spherical structures at the top of the quarry on the north face. There
is a short tunnel linking the main quarry with another and the roof of this
is remarkable for its projecting Giganto-productus and coral specimens all
over the surface. Detail of external ribbing is good and around the quarry a
few specimens of internal moulds of brachiopods illustrating well-preserved
muscle scars can be found. |
Via public right of way into this Shropshire Wildlife Trust site |
RIGS Yes. Designation because the site is extensive; rich in fossils and
demonstrates vividly important rock-forming processes. Evidence of faulting
and of sedimentary structures and variation in lithology reflecting
environment of deposition all combine to make this a very good RIGS. |
Structure and Sedimentology/Stratigraphy |
|
0852 |
SJ 277 256 |
Sweeney Mountain (west ridge) |
Quarry (disused) |
Upper Carboniferous: Millstone Grit: Cefn-y-Fedw Sandstone. Sheet 137. |
Quarry lies near the top of Sweeny Mountain. |
A large; disused quarry with some good clear exposures of Cefn-yr-fedw
Sandstone. There is scope for more examination of the strata here. In places
the rock forms massive crags with little trace of stratification but
elsewhere; the bedding planes are clearly defined and a dip of up to 40° E
can be measured. The rock is naturally cream in colour but often stained
orange; the iron compounds presumably derived from nearby Triassic rocks.
Texture is coarse and there are small scattered pebbles; and thin quartz
veins cut through the beds nearly vertical to the bedding planes. There is a
recessed shallow cave where a regular 250 mm horizon of sandstone is
surrounded by whitish; staining red; sandy shale. |
On private land adjacent to public footpath. |
RIGS Yes. Designation because this is a good site exposing the deltaic
Millstone Grit of the Namurian. Educationally this could be used with a
group especially in contrast with a limestone quarry such as Dolgoch and as
part of a study of the succession of sedimentary strata south of Oswestry.
There is scope to discuss the iron-staining and to examine the texture and
general lithology in relation to environment of deposition. |
Sedimentology/Stratigraphy |
|
0855 |
SJ 537 136 |
Haughmond Hill; Douglas's Leap |
Natural exposure |
Precambrian: Stretton Group: Burway Formation. Sheet 152 |
Cliffs at end of Haughmond Hill |
Around Douglas's Leap are vertical cliffs dropping into Queen Eleanor's
Bower. There are many and large exposures of green sandstones and flinty
shales; typical of the Stretton Group. Cliffs drop down into a valley which
seems to owe its existence to a fault line. It is not possible to record all
the exposures but from the 'Leap' views are magnificent and the rocks easy
to examine. Dips are always steep; near vertical and within the thinly
bedded shales are more massive sandstone beds; micaceous and medium grained.
There is a strong SW/NE direction of strike. The main exposure is extensive
and looks like a fault plane with slickensides running parallel to the near
vertical bedding. This may be imaginative observation and would need to be
confirmed or refuted. There are interesting structures e.g. dimple-shaped
ripple marks; parallel grooves going down the dip; a branching structure on
the surface. |
From footpath at top of hill |
RIGS Yes. Designation because the site is a spectacular exposure of shales
and sandstones of the Burway Formation; near to the boundary with the
Wentnor Group. Access is relatively easy. Also the association with the
fault and the interesting structures makes this possibly the best site at
the southern end of Haughmond Hill. |
Structure and Sedimentology/Stratigraphy |
|
0856 |
SJ 537 137 |
Queen Eleanor's Bower |
Natural exposure |
Precambrian: Wentnor Series: Bayston and Oakwood Formation: Haughmond
Conglomerate. Sheet 152. |
This is on the SW corner of Haughmond Hill overlooking the Severn Valley and
more distant hills. |
There are several exposures of the Haughmond Conglomerate showing pebbles up
to 100 mm across. The conglomerate is polymict; poorly sorted and the ratio
of pebbles to matrix is high. Sometimes the exposure looks like a concrete
wall! Roundness varies from well-rounded to angular and the matrix has a
purple coloration. Pocock states that there are up to 80-90% igneous clasts;
mostly rhyolite and felsite; the remaining 20% being quartz and quartzite. |
Easy access from footpath at top of the hill. |
RIGS Yes. Designation because this is one of three conglomerates within the
Bayston-Oakwood Formation and this is specifically linked to Haughmond Hill;
not being able to be traced with confidence south of Bayston Hill. The
exposures here are good and easy to study. It is possible to use this
exposure to put into context the rest of the rocks present at the southern
end of the hill as it lies unconformably upon the Stretton Group within the
Longmyndian in this locality. |
Sedimentology/Stratigraphy |
|
0857 |
SJ 537 138 |
Haughmond Hill Fort |
Natural exposure |
Precambrian: Stretton Group: Burway Formation. Sheet 152. |
Old Hill Fort. Fine viewpoint at southern end of the hill overlooking the
Severn; Shrewsbury and the distant hills. |
There are several exposures of a fairly massively-bedded sandstone;
generally grey in colour with a purple tinge in places. Unfortunately the
rock surfaces are weathered and covered with algae etc. so detail and
structures are hard to distinguish without much hammering. Where the bedding
can be seen; the steep dip is evident to the SE. The views here are
magnificent and of great geological interest in relating landscape features
to the underlying rocks. |
From public footpath. |
RIGS Yes. Designation because the site provides an excellent
geomorphological perspective; a continuation of that at SJ 542133 with a
prospect of Nesscliffe and Hawkestone and more Welsh mountains. As stated
above; one can gain here a valuable understanding of the relationship
between rocks and relief. These scores are based on the geomorphological
value of the site. The rock exposures; although useful in building up a
picture of Haughmond Hill's geology; would only justify LIGS. |
Geomorphology/Landscape |
|
0868 |
SJ 588 074 |
Charlton Hill Farm |
Track/roadside |
Lower Cambrian: Wrekin Quartzite. Sheet 152 |
On side of hill descending from small plateau of Uriconian Volcanics forming
Charlton Hill top. |
The exposure extends for more than 70 m parallel to the road. Bedding planes
are revealed clearly dipping 45° SSW. Ripple marks and many oblique joints
are visible. The rock is a well-sorted quartzite; grey when fresh but here
looking orange. The surface is algae-covered so detail is not clear. The
rock shows possible effects of being metamorphosed as the quartz grains are
fused together. |
Beside the public road. |
RIGS Yes. Designation because although there are more impressive exposures
of this Cambrian Quartzite in the Wrekin area to the NE this site is part of
the faulted inlier and is needed to gain a more complete picture of the
range of rocks on Charlton Hill and to understand its complex geology. |
Mineralogy/Petrology |
|
0882 |
SJ 625 013 |
Gleedon Hill - Much Wenlock |
Quarry (disused) |
Silurian: Wenlock Series: Much Wenlock Limestone |
Within the woods on the north of Wenlock Edge. |
This site shows a ballstone at ground level with clay pockets and bedded;
flaggy limestone dipping off the reef in a direction of 60°. Fossils in
sit' are clear to see; particularly corals e.g. Heliolites interstinctus.
Other fossils include crinoids; rhynchonellids and other brachiopods. There
is much replacement of original shell material by pink calcite. To the
left in a corner is a fault with much clay infill. Left of the fault is
crystalline; stratified limestone packed with highly fragmented crinoids
which becomes more nodular. Mudstone layers are clearly visible and the
nodules; both large and small are densely packed and look like a stone wall
with clay as 'mortar'. The dip seems to be at an angle of about 10° in a
northerly direction. |
Take a footpath on the left; a few metres along the Sheinton Road from the
junction with the A4169. Go left into the wood at a store place where there
is often litter. After about 300 m the path bears left where an exposure is
seen on the right. This is not the exposure described here but 10 m on the
site can be seen through the trees on the left. Access in summer is
difficult because of the vegetation. |
RIGS Yes. RIGS status on account of the variety of features typical of
Wenlock Reef Facies and its related strata. The fault is of interest as is
the range of fossil material present. |
Fossils and Sedimentology/Stratigraphy |
|
0883 |
SJ 626 009 |
Shadwell Quarry - Much Wenlock |
Quarry (disused) |
Silurian: Wenlock Series: Much Wenlock Limestone. Special Sheet 60 -
Telford. |
Once a hill; now a deep pit below Windmill Hill. |
The sight of the deep blue pool surrounded by grey; terraced faces from the
rim is a spectacular one. At the top there is grey shale on the RHS and on
the left is mostly Reef Limestone; these forming the top terrace and rim of
the quarry. Below is thinly bedded grey limestone and shale; which rests on
whiter; more crystalline limestone. This; in turn; lies on more shaly beds.
Fossils abound; especially brachiopods e.g. Atrypa reticularis; Leptaena
depressa; Meristina obtusa; some large and well-preserved. Calcite; both
white and pink; and with dog-tooth crystals is common. Because of steepness
of faces it is not easy to examine all the strata closely. Near the entrance
the slope down to the first level seems to be of olive mudstone possibly an
exposure of Lower Ludlow shales |
Unofficially it is easy to get in to the quarry at the moment and permission
can be obtained from Lafarge-Redland. While the restoration work is going on
there is no problem but the situation is due to change. See Ownership. |
RIGS Yes. RIGS on account of (1) its fossils; (2) the contrasting limestone
/shale horizons; (3) typical ballstone structures; albeit disturbed by
quarrying. |
Fossils and Sedimentology/Stratigraphy |
|
0892 |
SJ 6615 0580 |
Lydebrook Dingle (S) |
Quarry (disused) |
Lower Carboniferous: Lydebrook Sandstone. Special Sheet 60 - Telford |
On the side of a wooded valley above the Dingle. |
An excellent site for examining the Lydebrook Sandstone just off the public
footpath with easy access. The quarry is approx. 20 m across and the faces
rise to a max. height of 5 m. The colour of the rock is striking; being
creamy brown; weathering orange. The sandstone shows cross-bedding and
possible channelling. It is mainly coarse and is sometimes well-sorted but
in other places is conglomeratic; the pebbles showing stratification.
Thickness of beds is variable and the dip direction and angle changes within
the quarry; because of the cross-bedding. The site displays good fresh rock
exposures. |
Easy. Use the public footpath; the Shropshire Way; towards Leasows Farm.
Quarry is easily seen and reached shortly after the path bears left out of
Loamhole Dingle. |
RIGS Yes. An excellent; easily accessible old quarry; suitable for a group
of students and one which allows close examination of the characteristics of
the basal member of the L. Carboniferous as it reflects a shallow
transgressing sea. Particularly good when looked at along with the basal
conglomerate at site SJ662058. |
Sedimentology/Stratigraphy |
|
0893 |
SJ 6615 0335 |
Benthall Edge Cottage |
Quarry (disused) |
Silurian: Wenlock Series: Benthall Beds. Special Sheet 60 - Telford |
Quarry is cut into the top of Benthall Edge and is north-facing. |
Quite impressive exposures here extending along the crest for about 100 m.
There is a variety of massive to flaggy fossiliferous; mainly crystalline
limestones inter-bedded with shales and siltstones. The standard section for
the Benthall Beds is at a nearby site on Benthall Edge but there is much to
be seen here. There are a series of old quarries following the line of the
crest. At the most westerly end of this site; near a footpath which goes to
Benthall Hall; the lower beds are 0.25-0.3 m thick and nodular on the
underside. Above 2 m the limestone becomes nodular; the strata much thinner
and they alternate with green/brown mudstone. The latter is weathering to
clay and tends to wash down and cover the surface of the rock. Height of
face is 9-12 metres. The top beds project in a more resistant layer of
flaggy limestone. About 10 m east is a vertical 'blasted' face where
ballstones can be seen surrounded by nodules embedded in mudstones and
shales. The rock has plentiful corals and brachiopods typical of the Wenlock
Limestone. At the east end; nodular strata dips at about 24° to the SSE. The
nodules result in undulating partings between beds. |
Easy via public footpath from Ironbridge or Benthall Hall. |
RIGS Yes. The whole of Benthall Edge is worthy of designation as RIGS but
there are several separate sites worthy of this status in their own right.
This is one such which offers ease of access and allows the variations in
the Benhall Beds to be studied. The massive flaggy nodular and shaly/ muddy
layers and also some reef structures provide evidence of changing
environments during the period of deposition. |
Sedimentology/Stratigraphy |
|
0894 |
SJ 662 057 |
Lydebrook Dingle |
Natural exposure |
Lower Carboniferous: Lydebrook Sandstone. Special Sheet 60 - Telford |
On the valley side of a deep wooded narrow dingle. |
An exposure of the conglomeratic phase of the Lydebrook Sandstone. Main
exposure is 10 m long and 2.5 m high. It forms a massive face of coarse
conglomerate with 0.3 m of weathered sandstone at its base. Pebbles are
mainly quartz or quartzite; densely packed; and very varied in size; ranging
from 50 mm down to a few mm. Shape is sub-rounded to sub-angular and the are
set in a sandy matrix. On the right of the face the pebbles show evidence of
layering and possible cross-bedding. These layers seem to dip approx.
north. The pebble horizon gives way to sandstone higher up the face; the
boundary being very sharp. |
After the Ropewalk; follow footpath as it bears left uphill. Turn sharp
right at the yellow footpath sign and site is 30 m over a bank. No problem
about access. |
RIGS Yes. An impressive conglomerate exposure in the Lydebrook Sandstone;
one to which one could take small groups without fear of damage; can examine
face close-up. Illustrates deposition in a shallow marine sandbank-type
environment. |
Sedimentology/Stratigraphy |
|
0895 |
SJ 662 058 |
Lydebrook Dingle |
Natural exposure |
Lower Carboniferous: Lydebrook Sandstone. |
On the side of a steep narrow valley above the stream. |
Stoney Hill fault crosses the dingle from SW to NE causing greater amount of
Lydebrook Sandstone to outcrop at this locality. It can be seen forming
massive rocky sides (20 m high) to the valley from this point north and
west. Some of the exposures are weathered and covered with algae but there
are a number of excellent ones. This is the smallest of three possible RIGS
or LIGS sites. The sandstone is fresh; cream/orange. The middle of the
exposure shows evidence of channelling as the base of the massive bed is
distinctly concave and seems to rest a thinner layer of softer; more clayey
sediment and a pocket of lighter sandstone with carbonaceous fragments.
Above and below; the sandstone is massive. |
As the main footpath from the Ropewalk bears left; continue down towards the
stream along a less-used path. Before reaching the stream; the exposure can
be seen up the slope to the left. Access is not difficult. |
RIGS Yes. Very useful when studied in association with other sites in the
Dingle. Shows the characteristics of a basal deposit laid down at the
beginning of a marine transgression; pebbles; coarse sand; and plant
fragments. |
Sedimentology/Stratigraphy |
|
0900 |
SJ 6635 0575 |
Loamhole Dingle - The Gorge |
Stream/brook |
Silurian: Wenlock Series: Wenlock Shale: Coalbrookdale Formation. Special
Sheet 60 - Telford |
Within a deeply cut dingle exposed on the high bank above the stream. |
Next to a water tunnel and waterfall is a vertical bank of Wenlock Shale;
4.5 m high and extending at least 0.5 m under water. The 'shale ' is more of
a mudstone here; uniform and breaking into small; multi-sided; thin
fragments. About 0.5 m above water level is a definite recess; indicating a
more clayey layer. In front of the face is a deepish pool fed by water from
the tunnel; this makes access to the face rather difficult. About 9 m
downstream; is a 10 m long bank of the same rock. Dalmanites caudatus and
orthocones are relatively common |
From Museum of Iron; along the Ropewalk and then via the stream bed. |
RIGS Yes. The exposures of Wenlock Shale; (Coalbrookdale Formation) in
Loamhole Dingle are the best north of the Severn; according to the Telford
Memoir. This is a particularly clear and representative example with
abundant fossils; especially trilobites and cephalopods. |
Fossils and Sedimentology/Stratigraphy |
|
0901 |
SJ 664 034 |
Pattins Quarry - Benthall Edge |
Quarry (disused) |
Silurian: Wenlock Series: Benthall Beds. Special Sheet 60 - Telford |
Quarry forms elongated 'valley' feature below the top of Benthall Edge. |
There are many features of interest in this quarry; which is taken as the
standard section for the Benthall Beds. These are massive to flaggy; shelly;
crystalline limestones with nodular horizons and shaly partings. There is
evidence of a ballstone with a pocket of nodular limestone within it. Above
this is more nodular limestone with projecting slabs of resistant;
crystalline material. Beds dip at an angle of about 25° and in an approx. SE
direction. At the SW end the face shows clear evidence of faulting; there is
displacement of 0.5 m to the left and softer strata 'slump' towards the
fault plane. Other small faults occur and give rise to small scale
step-faulting. Nodules cause undulations between beds and a small monoclinal
fold is seen. The quarry is an excellent place for the collecting of fossils
from the many rock fragments lying around; the Benthall Beds containing many
corals; stromotoporoids and typical Wenlock brachiopods. |
|
RIGS Yes. This quarry has within it the standard section for the Benthall
Beds and that alone recommends the site as RIGS. However; there are other
features as well as the impressive section through these varied limestones;
particularly the examples of faulting and small-scale folding and the range
of fossils present in the quarry. |
Structure and Sedimentology/Stratigraphy |
|
0904 |
SJ 670 039 |
Lincoln Hill - Ironbridge |
Quarry (disused) |
Silurian: Wenlock Series: Benthall Beds. Special Sheet 60 - Telford |
Lincoln Hill stands imposingly at the western end of the Ironbridge Gorge
above the N bank of the R. Severn. The quarry and best exposures lie on the
steep east side of the hill. Below Lincoln Hill are deep underground
caverns in the limestone; the legacy of extensive mining in the Gorge. |
Along the path from the top of Church Road to the Rotunda are several
exposures of the reef facies; easily examined and providing a good range of
shelly fauna. On the left are about 10 m of Benthall Beds half a metre high.
Next to this is a small quarry of grey; nodular limestone with indistinct
bedding up to 4 m high in the upper exposure and 2 m high in the lower one.
The rocks appear to be dipping SE at about 36°. At the bottom of the
exposure; the stratification is clearer; nodules less distinct and there
appears to be part of a ballstone. There are many fossils; often very
fragmented; but a good stromotoporoid was observed and rhynchonellid
brachiopods. Immediately parallel to the Rotunda path is a depression
(presumably a former small quarry) where there are further exposures of
clean nodular beds of limestone and here many fossils can be found in the
loose fragments on the ground. The most useful fossil sites are on the steep
east face above the old quarry. One face of the old quarry is freshly
exposed and thin irregular beds of Wenlock Limestone are seen to be dipping
ESE; towards the top of the face layers become more regular. The rocks are
cream/brown in colour; typical of the Wenlock limestones. |
Via footpaths from various roads leading from Ironbridge up to Lincoln hill.
Although much of Lincoln Hill is open access; permission is needed to visit
the old quarry and the fossil sites on the east face. |
RIGS Yes. Already an SSSI; Lincoln Hill is an historically famous fossil
locality. The abundant shelly fauna have been studied since the time of
Murchison; who first described the site.This is the type locality for a
number of fossil groups; notably ostracods; and in the last few years has
played a key role in fresh studies of the fossil fauna of the Wenlock
Series; detailed studies of the fauna of Lincoln Hill have been important in
understanding the environment of the reefs and the adjacent backreef lagoon. |
Fossils and Sedimentology/Stratigraphy |
|
0905 |
SJ 672 039 |
Lincoln Hill - Ironbridge |
Natural exposure |
Upper Carboniferous: Lower Coal Measure Sandstone. |
Exposure is at the top of Lincoln Hill. |
There is a tongue of rock just off the Limeburner's path to the Rotunda. At
its base is what seems to be the opening to a tunnel. Here; sandstone;
weathering brown can be seen dipping at about 18° SE. The sandstone is
light in colour and fine-medium textured with little evidence of
cementation; the sand grains rubbing off on one's fingers. The exposure is
about 3 m high and rests unconformably upon the Benthall Beds although at
this site the contact is not visible. |
A few metres on the right of the Limeburner's path to the Rotunda;
approaching from the top of Lincoln Hill road. |
RIGS Yes. The site provides an easily accessible example of Coal Measure
Sandstone next to the Silurian Limestone exposures on Lincoln Hill. |
Sedimentology/Stratigraphy |
|
0906 |
SJ 6725 0405 |
Lincoln Hill - Ironbridge |
Quarry (disused) |
Upper Carboniferous: Lower Coal Measure Sandstone overlying Silurian:
Wenlock Series: Benthall Beds. Special Sheet 60 - Telford |
The exposure is on the NW-facing slope of an elongated former quarry on the
top of Lincoln Hill |
Light grey; weathering brown; 0.6-0.7 m thick massive sandstone is dipping
at approx. 20° SE. Texture is that of a medium sand and this rock is
underlain by 0.2 m of soft grey shale which weathers to clay. The shale
tapers out to the right and seems to form a pocket between the sandstone and
hard crystalline limestone beneath. This is a good example of the
unconformity between Wenlock Series and the L. Coal Measures. The base of
the sandstone is a thin pebbly layer; suggesting a basal conglomerate. The
limestone here becomes more nodular beneath the massive horizon and is
crinoidal. |
Fairly easily reached by turning sharp right off the Limeburner's path along
the bottom of the now naturalised old quarry and then looking up the slope
to the right. |
RIGS Yes. Designation because this is a very good example of an unconformity
between Silurian Wenlock Series and the overlying Lower Coal Measure
Sandstone where the contact is clearly visible. |
Sedimentology/Stratigraphy |
|
0910 |
SJ 729 158 |
Lilleshall Hill |
Natural exposure |
Precambrian: Uriconian Volcanics. Special Sheet 60 - Telford |
Lilleshall Hill rises dramatically from the surrounding plain to a height of
132 m AOD. The Uriconian crags are on the top. Forms smooth dipping plane on
NW side of the hill. |
These rocks are described in 'The Regional Geology of Central England' as
albite rhyolites with tuffs and breccias. The exposures are very impressive
with flinty fine-grained pink rhyolites showing rock cleavage in an approx.
E-W direction. This has the effect of producing parallel slabby small faces
exposed almost en echelon along the top of the hill; trending in line with
the Lilleshall Fault. On the east side of the hill just below the monument
there is a marked boundary between the cleaved rhyolites and the irregular
masses of coarse tuffs. Fragments of flow-banded rhyolite 10 mm long are
clearly seen in the tuffs. Examples of a more coarsely crystalline tuff much
deeper red in colour are also present on and around the hill. On the NW side
the rhyolites are splintered and seem shattered presumably the result of
faulting which is also responsible for the cleavage lineation. A very
striking steep smooth slabby exposure of the Lilleshall Fault forms the edge
of the hill on the west. The abrupt change of slope at the foot of the hill
here corresponds to the faulted margin. It is possible to see multiple
parallel fault planes close at hand. The height of the fault plane is
approx. 15 m. |
From the road that goes round the hill; enter a wooded area over a wire
fence at the NW end. Others obviously go in here although it is not a public
footpath. |
RIGS Yes. Not only on account of its geomorphological value but because here
are exposed the most northerly Uriconian rocks along the Church Stretton
Fault System. Also the varying textures of the volcanic rocks can be easily
be examined. An excellent example of a large fault plane made more special
as it is the northerly end of the Church Stretton Fault System and when
standing on the top of the hill; it can be lined up with the Wrekin and the
trend determined. |
Mineralogy/Petrology |
|
0911 |
SJ 734 165 |
Lilleshall (N) (limestone quarries) |
Quarry (disused) |
Lower Carboniferous: Dinantian: Visean: Carboniferous Limestone. Sheet 153;
Wolverhampton. |
Deep excavated chasms; once quarried now very overgrown. |
At first sight no rock seems visible because the steep slopes are covered
with slipped soil and thick ivy and other vegetation; including many fallen
trees. A large specimen of Lithostrotion junceum was embedded in the path
and there was evidence of other limestone fragments scattered around. There
are large pools with obscured faces going steeply into the water with no
access. Below a lower path; however; formerly a quarry track with lime kilns
and tunnels; a good exposure of limestone was present. It is possible to
reach this exposure and near-horizontal; irregularly bedded limestone rises
to about 16 m forming the edge of excavation. This seems to be the level
down to which quarrying as opposed to mining which also took place here; was
carried out. There are recesses in the face; some of which represent a red
shale within the limestone. The limestone is cream/pink in colour; fine
textured; nodular in appearance and dense. This is described in the Telford
Memoir as concretionary. |
Open access via footpaths in the woods at the North end of Lilleshall. |
RIGS Yes. Part of the faulted Inlier at Lilleshall and the only
Carboniferous Limestone north of the Wrekin area in the east of the county.
It also completes the geological picture of the compact Lilleshall Inlier
itself. |
Sedimentology/Stratigraphy |
|
0912 |
SO 585 977 |
Knowle Quarry - Wenlock Edge |
Quarry (disused) |
Silurian: Wenlock Series: Much Wenlock Limestone Formation. Sheet 152 or
SO59. |
On the dip slope of Wenlock Edge. |
The quarry illustrates very well the relationship between bioherm reef and
inter-bedded nodular and uniform Silurian limestones of the Wenlock Series.
There are thin beds of shale which weather more quickly and form recesses. A
good example of arching can be seen above the reef. The south end of the
quarry has uniform thin beds of stratified limestone and shale. At the north
end is a fault with a calcite vein. Reef-building stromotoporoids and
colonial corals (mostly tabulate) are abundant and many other typical
fossils are found e.g. crinoids brachiopods inc. Leptaena depressa bryozoans
Poleumita discors and centrifugus and occasional trilobite fragments. Quarry
is approx. 40 m wide and height of exposures is up to 8 m. At the bottom of
the steps at the S end is a smaller exposure showing reef structures and
stratified limestone. Here it is possible to examine the face close up. |
This quarry is 4.5 km SW of Much Wenlock. Access from NT car park and public
footpath. It is necessary to keep to the paths here in order to protect wild
flowers. |
RIGS Yes. An excellent example of patch reef and relationship with
interbedded nodular and tabular limestones (Silurian). There are other
features such as fault and mineralisation. |
Fossils and Sedimentology/Stratigraphy |
|
0915 |
SO 463 924 |
Hazler Quarry - Hope Bowdler |
Quarry (disused) |
Precambrian (Uriconian Volcanics); Ordovician (Caradoc Series: Harnage
Shales) |
On the SW side of Hazler Hill |
The quarry is located in Uriconian basalt and tuffs which can be seen to dip
50-80° N. The basalt is weathered showing blue-green mineralisation; the
dolerite is green. There is a Neptunean dyke in the right-hand corner of the
quarry - see Toghill and Greig. The 70 mm cleft has been cleaned out since
February 2000 but is increasingly deeply recessed with a smooth surface
filmed with water and algae so not readily identifiable for what it is. The
few fragments of brown weathered Harnage Shale infill nearby were difficult
to identify and showed no evidence of fossils. This site although well-known
and considered to be important is now very disappointing. |
Beside public lane. |
RIGS Yes. Designation because the presence of the Neptunean dyke within the
Ordovician/Precambrian unconformity is the only local example. |
Sedimentology/Stratigraphy |
|
0917 |
SO 467 908 |
Chelmick below Little Coppice |
Bank |
Ordovician: Caradoc Series: Cheney Longville Flags; sandstones and
siltstones. Sheet SO49. |
Brook runs down the dip slope of the strata towards Hatton. |
A series of small rapids in the brook running down the bedding planes with a
dip which is 20-25° SE. Harder bands (the sandier layers) cause the rapids
to form; these alternate with shales to give a rapid and plunge pool effect.
The sandstone is finely laminated and splits along the partings like a
shale. It is soft ginger and micaceous and sometimes has a nodular-like
upper surface. A good example of ripple marks was seen. The shaly layers
tend to yield more fossils which include Dalmanella wattsi; Sowerbyella; and
Strophomena grandis as part of a typical Marshbrookian fauna. |
Beside public right of way (as now diverted along field boundary) |
RIGS Yes. Designation because of the clear exposure of a succession in the
Cheney Longville Beds of fossiliferous stronger and weaker sandstone and
shaly bands (the latter replaced by small plunge pools); the excellent
ginger sandstone itself appears in a range of strengths. Beautiful parallel
ripple-marks. Its combination with the sites at Chelmick Farm and Chelmick
Little Coppice provides a useful succession of exposures within the Cheney
Longville Beds. |
Fossils and Sedimentology/Stratigraphy |
|
0934 |
SO 552 944 |
Wilderhope Youth Hostel Entrance (Lutwyche Hall) |
Cutting (road/railway) |
Silurian: Wenlock Series: Wenlock Limestone. Sheet 166 |
At the crest of Wenlock Edge. |
A 60 metre length of limestone face exposed a few metres back from the
public road; up to 8 m in height but diminishing to the NE. The clearest
section is 15 m long at the SW end. Dips 12° SE. The rock is cream/grey with
flaggy finely crystalline projections but generally discretely nodular with
shale partings and consequent wavy partings between beds. The occasional
thick resistant layers have uneven undersides with shales below. At the S
end the shale is more substantial than further N; up to 50% of the face.
There are two major near-vertical joints at the SW end with shaly infilling;
these may be faults but if so movement has been slight. There are fragments
of small brachiopods and evidence of crinoids. |
Beside public road. |
RIGS Yes. Designation because it lies in the transition zone between the
'reef tract' to the NE and the 'off reef tract' to the SW. It shows a
variety of limestone lithologies effectively including micrite bioturbated
wackestone and pelmatozoan debris. |
Sedimentology/Stratigraphy |
|
0935 |
SO 5620 9555 |
Easthope (NE) - Wenlock Edge |
Cliff |
Silurian: Wenlock Series: Much Wenlock Formation (reef ). Sheet SO59. |
Just below B4371 on the scarp face of Wenlock Edge. |
Two adjacent exposures. The higher one consists of nodular reef facies
bedded with clay between the nodules. The limestone becomes more flaggy at
the top of the section just below the road. There is then a 5 m barrier of
vegetation and then a ballstone; rather overgrown; up to 0.9 m across; can
be seen at a lower level within the Tickwood Beds. The usual common Wenlock
reef fauna is present. The Tickwood Beds (Coalbrookdale Formation Farley
Member) can be seen to the right of the ballstone. These are nodular with
regular 50-60 mm beds as well as clay partings. No actual contact visible
between the Much Wenlock Limestone Formation and the Tickwood Beds. |
Easy access down a track from the B4371. It is a safe and easy site to
study. |
RIGS Yes. This is already an SSSI on account of its being the most southerly
exposure of Wenlock Reef facies on Wenlock Edge. |
Sedimentology/Stratigraphy |
|
0936 |
SO 563 917 |
Shipton (Old Lane) |
Track/roadside |
Silurian: Downton Series: with 'Ludlow Bone Bed' at base; overlying Ludlow
Series: Whitcliffe Beds. |
Lane on the dip slope of the Aymestry Limestone towards Corvedale |
Here the basal bed of the Downton Castle Sandstone (2.4 m) is apparently
overlying the Ludlow Bone Bed which is said to occur (B.A. Hains) as two
impersistent beds (13 mm thick and 100 mm apart). Although the present
surveyor found possible evidence of this identification was inconclusive.
Buff silty shales of the Downton Castle Sandstone were seen as were the
succeeding yellow flaggy sandstones. The latter were fine grained and
micaceous with cross-bedding and fine laminations. But as the lower beds of
the Downtonian were silty (and therefore similar to the upper Whitcliffe
especially as the surfaces were strongly weathered) the boundary was
difficult to define. Nevertheless one metre above ground level a recess may
have been the position of the Bone Bed particularly as below it the
siltstones seemed more lime-rich and a Fuchsella amygdalina was found in
situ. |
Beside public lane |
RIGS Yes. Designation because this is the only well-preserved and accessible
exposure of the transition from Upper Ludlow Shales to Downton Castle
Sandstone in this area Exposures of the Ludlow Bone Bed are rare so this
site (with its potential for showing the environmental change across the
Ludlow/Downton boundary) is of great value. |
Sedimentology/Stratigraphy |
|
0939 |
SO 569 965 |
Wenlock Edge - Ippikin's Rock |
Cliff |
Silurian: Wenlock Series: Much Wenlock Formation; reef facies. Sheet SO59. |
Reef is part of the scarp face of Wenlock Edge. A wonderful view where the
underlying rock type can be related to the surface topography. View looks
from Silurian Wenlock Series (limestone and shales); across Llandovery
Series (Hughley Shales and Kenley Grit) to the Ordovician and beyond to the
Precambrian Longmyndian and Uriconian. |
Spectacular massive high face of reef limestone where the reefs are at their
highest. Reef limestone is inter-bedded with nodular regular beds which
resemble a stone wall. Strong vertical joints split the reef face. A
prominent rounded stromotoporoid about 0.5 m above the base appears to have
been a trigger to reef building. The face is weathered and this obscures the
fossil content of the rock but crinoids tabulate and rugose corals are
present along with brachiopods and bryozoa. The visible relationships
between reef and shelf limestone and reef and mudstone are very clear.
Exposure is 15 m high and 28 m wide. Regarding the view the Edge can be seen
running south-westward (the escarpment being off-set by faults along its
length). The Longmynd and the volcanic hills of Lawley Caradoc and the
Bowdlers rise steeply in the distance while the rolling topography of
alternating resistant and less resistant grits and shales reflects the
underlying rocks. The position of the basal Llandovery can be appreciated as
can the line of the Church Stretton Fault running between the Wrekin and the
Stretton hills. |
Open access to the Ippikin's Rock view-point and to the footpaths on Wenlock
Edge. A path leads from the view-point to the right. A few metres further on
turn left along a much lesser used path which brings you to the foot of
Ippikin's Rock. Do not park in the car park of the Wenlock Edge Inn without
asking permission. Landlord likes custom but isn't keen on field groups with
muddy boots. |
RIGS Yes. Designated as RIGS as the site provides an excellent example of a
Wenlock Edge patch reef at its maximum development and allows easy
examination of the relationship between the reef and surrounding modualr and
tabular limestone beds. |
Sedimentology/Stratigraphy/Geomorphology/Landscape |
|
0940 |
SO 573 968 (SO 571 967 on GIS) |
Upper Hill Farm (SE) - Wenlock Edge |
Cutting (road/railway) |
Silurian: Wenlock Series: Wenlock Shales: Coalbrookdale Formation: Apedale
Member. |
Foot of the scarp slope of Wenlock Edge. |
This old railway cutting exposes grey/brown/green weak mudstones; easily
weathered and crumble to scree. Bedding is thin and irregular. Some beds are
more resistant and contain discrete larger rounded nodules. Along the bank
about 25 m from the N end there is evidence of alternating resistant and
less resistant rock layers; some strata are more crystalline. Fossils are
scarce; merely a few small brachiopods. There are prominent diagonal joints
and large nodules; general dip direction is SE. Height of exposure 3-4 m and
about 90 m is exposed along the path. Reflects a tropical sea environment
but one where the sea was deeper and muddier than with the succeeding Much
Wenlock Limestone. |
Open access along public footpaths. Nearest carpark is at Presthope (NT). |
RIGS Yes. Provides one of only a few exposures of the Apedale mudstones
(Wenlock Shale) and is important for interpreting the Wenlock Series
succession of the area. |
Sedimentology/Stratigraphy |
|
0941 |
SO 574 966 |
Lilleshall Quarry (SW end) - Bourton |
Quarry (disused) |
Silurian: Wenlock Series: Much Wenlock Formation: Reef facies; and Wenlock
Limestone. Sheet SO 59 |
At the top of the dip slope of Wenlock Edge; forming an elongated 'valley'
parallel to the crest. |
On the north side the main face rises dramatically up to the road. From a
distance the relationship between reef and stratified limestone can be
appreciated as the ballstones and their effect on the surrounding rocks is
clearly visible. Lying on the ground are large blocks of limestone which are
often slickensided and mineralised with calcite. Crystals of calcite are
large well-formed rhombs forming aggregates. The link between calcite
mineralisation and faulting soon becomes apparent as a few metres SE of the
main face is a calcite vein some 350 mm thick which runs diagonally across a
broken ballstone at ground level. To the left of this is a vertical
shatter-zone where faulting has resulted in calcite mineralisation and
brecciated reef limestone. Between this and another sub-parallel fault the
rocks have been displaced downwards and Lower Ludlow Shales appear at the
top of a narrow 'pinnacle' of limestone. Between the broken reef and
stratified limestone dipping SE at about 15° a 3 m wide section of weak
stratified weathered rock with thin beds of discontinuous calcareous nodules
occurs. This seems to be a rather atypical exposure of the down-faulted
Lower Ludlow Shales altered by the faulting and subsequently weathered.
There are several features of interest near the middle of the quarry. The
floor is of grey fine gently dipping limestone which has a palaeo-karst
appearance. This can be seen exposed on the north side amidst the quarry
waste which buttresses the faces. There are many fossils: surprisingly
corals e.g. Favosites gothlandicus; brachiopods e.g. spiriferids;
rhynchonellids; strophomenids; gastropods and a glabella of a trilobite (15
mm long). Here the conditions were low energy marine with some evidence of a
very shallow sea even emergence because of trails and other signs of
bioturbation. The sediment was fine deposited as a limy mud. On the south
side of the quarry in this area are two separate 'stacks' of limestone left
after quarrying. One shows very clearly lower greyer thicker strata divided
from crystalline layers with shale partings by a 120-150 mm layer of shale.
Rocks are dipping approx. SE at 10°. There are fewer fossils here. The face
is 9 m high. The second 'stack' is a bit higher in the succession and
consists of coarse grey crystalline limestone |
Enter via a track opposite the works on the Bourton road. There are no
restrictions to prevent access although permission should be sought from the
Bardon Company at Lea Quarry. |
RIGS Yes. This is an outstanding site. Not only is there a splendid shatter
zone with its effects clear to see but the Lower Ludlow Shales become
exposed in a most interesting way. The calcite mineralisation is impressive
and the massive blocks of limestone are unusual along Wenlock Edge. Also the
far end of Lilleshall Quarry is a delightful place with all sorts of
wildlife. |
Structure and Sedimentology/Stratigraphy |
|
0944 |
SO 579 971 |
Lilleshall Quarry entrance |
Quarry (disused) |
Silurian: Wenlock Series: Much Wenlock Formation: Reef facies; and Wenlock
Limestone. |
At the top of the dip slope of Wenlock Edge; forming an elongated 'valley'
parallel to the crest. |
This quarry has many interesting features. The high faces at the SW end of
the site give an impressive view of the inter-relationship between
ballstones and surrounding stratified limestone. These high near vertical
faces do not allow close examination and are better viewed from a distance.
However there are other more accessible places which display splendid
geological features. At the entrance to the quarry itself a long exposure
runs at right angles. Light grey fairly coarsely crystalline thin slabs
occur with olive siltstones. The former weather brown and contain scattered
crinoids some 100 mm across. There is much clay between the layers. The
colour of the crystalline limestones varies from light brown to a deep grey
and there is also variation sometimes sudden in texture. Calcite is common
often pink there being large and well-formed crystals. Within the stratified
limestone small ballstones occur which result in what appears to be folding
in the surrounding rock. Further along the exposure there is more
fine-grained muddy limestone with paper shales grey in colour. A fault can
be seen showing mineralisation of 20-30 mm thick calcite with slickensiding
and brecciation of both rock and calcite. The fault has an E-W trend.
Dimensions: 70 m long and 4 m high. |
Enter via a track opposite works on the Bourton road. There are no
restrictions to prevent access although permission should be sought from the
Bardon Company at Lea Quarry. |
RIGS Yes. RIGS status because of the variety of features to be seen:
ballstone within stratified limestone; crinoidal; crystalline limestone
contrasting with shales; effects of a fault. The whole quarry deserves RIGS
status but there are separate sites which need to be described in their own
right. |
Fossils and Sedimentology/Stratigraphy |
|
0945 |
SO 581 974 |
Wenlock Edge - Cliff and Roof of Presthope Tunnel |
Cliff |
Silurian: Wenlock Series: Much Wenlock Formation; and Coalbrookdale
Formation: Wenlock Limestone and Shales. Sheet SO59. |
Above roof of old railway tunnel through scarp slope of the Edge. |
A thick sequence of inter-bedded mudstones and thin nodular limestones is
exposed at and above the tunnel entrance. These represent the Farley Member
of the Coalbrookdale Formation. They illustrate a transition between the
underlying mudstones (Apedale Member) and overlying Much Wenlock Formation
above. At the base of the cliff limestones are nodular within thicker
mudstones; higher up layers of coalesced nodules are separated by thin
shales. Colour changes from green/brown at the base to grey/white at the
top. Width of exposure is 10 m; height approx 15 m. Fossils are scarce in
the mudstones but the strata become more fossiliferous with typical Wenlock
fauna further up the cliff. This reflects deeper muddier conditions becoming
clearer and shallower in a tropical marine environment. |
From Hughley road take footpath along Presthope cliff section and go down
the steps leading to the roof of the tunnel. Can also be approached from the
opposite direction along the old railway line from the Ippikin's site. |
RIGS Yes. Importance lies in the transitional nature of the lower series
(from underlying mudstones to Upper Much Wenlock Formation) and the obvious
White Much Wenlock Formation above. Talus gives representative specimens. |
Fossils and Sedimentology/Stratigraphy |
|
0946 |
SO 5817 9743 |
Wenlock Edge - Presthope cliff section |
Cliff |
Silurian: Wenlock Series: Much Wenlock Formation. Sheet 152 or SO59. |
Scarp slope of Wenlock Edge. |
Shows patch reef development in the Much Wenlock Formation and variation in
inter-reef limestone lithologies. The reef here is low and discontinuous.
Thin bands of shale are present. The inter-bedded limestones are nodular or
tabular occurring in fairly thin beds. Some crinoid-rich beds are thicker.
There is evidence of slickensided surfaces indicating post diagenetic
strike-slip movement along joints. At the end of the section (nearest the
Hughley road) there is clear evidence of the bioherm causing the underlying
beds to be depressed and warped. The section is 50-60 m long; height
variable up to 7-8 m. Calcite mineralisation is often present. Fossils found
include reef-building corals and stromotoporoids e.g. Halysites Favosites
and many non-reef building organisms e.g. crinoids bryozoa and many
brachiopods; representative of a clear shallow tropical sea. |
From NT car park GR583975; approach from the Hughley road and use public
footpath along the section. |
RIGS Yes. Its importance lies in the clear examples of small patch reefs and
their relationship with interbedded nodular and tabular limestones. |
Fossils and Sedimentology/Stratigraphy |
|
0949 |
SO 617 993 |
Much Wenlock |
Cutting (road/railway) |
Silurian: Ludlow Series: Leintwardine Beds. |
Track cutting next to road out of Much Wenlock into Corvedale. |
The rocks here are mostly olive mudstones with lenses of crystalline grey
limestone. There is much calcite (sometimes pink); large crystals. The
shales and mudstones are thinly bedded with irregular partings. The exposure
is about 40 m long and 5 m high. There seems to be a significant boundary
below which the rock is fragmented whilst above it are more regular strata
of thicknesses varying from 300 mm to 30-40 mm. Dips are variable too; not
consistent with the general SE dip of Ludlow strata and with angles of
inclination ranging from 18° to 45°. This may be the result of faulting
close at hand. Rocks are very fossiliferous; there are many finely
comminuted fossils in the more crystalline shelly strata but preservation is
better in the siltstones. Fossils include Fuchsella amygdalina Camarotoechia
nucula Salopina lunata and many others. |
On private land beside farmer's track into field |
RIGS Yes. Designation because the site displays a good exposure of U.
Leintwardine strata with a typical range of fossils which can be studied;
there are few such sites in the Much Wenlock area. It also shows evidence of
faulting and calcite mineralisation. From the geological map Sheet 152 it
can be seen that the exposure forms part of a narrow rift valley. |
Fossils and Sedimentology/Stratigraphy |
|
0952 |
SO 717 928 |
Castle Hill Gardens (East) - Bridgnorth |
Cliff |
Permian: Bridgnorth Sandstone. Sheet 167 (Dudley) - old map; different
nomenclature. New names from Toghill 1990. |
Sandstone cliff with caves on south side of River Severn |
In the cliffs beneath the public gardens the sandstone cliff rises
impressively. Large scale trough cross-bedded units are inter-bedded above
and below with planar cross beds. There are many caverns; the remains of
excavated dwellings; and at the southern end one of these is accessible and
shows a three-dimensional section. |
Observable from public gardens belonging to Bridgnorth Council. The outcrop
stands some 20 or 30 metres back from the road and this area is well
maintained by the council as a publoic amenity. |
RIGS Yes. RIGS classification as it is the type section for the Bridgnorth
Sandstone. Displays complex of trough and cross-bedded sandstone units which
represent westward-migrating draa dunes with superimposed barchan and linear
dunes. |
Sedimentology/Stratigraphy |
|
0953 |
SO 724 939 |
High Rock - Bridgnorth |
Cliff |
Lower Triassic: Kidderminster Conglomerate; lying on top of Permian:
Bridgnorth Sandstone. |
Summit of the sandstone ridge where there is a marvellous view (especially)
in winter towards Bridgnorth across the R. Severn. |
The dunes of the Permian Sandstone drop 70 m sheer to the road. There are
several crags by the path with exposed bedding planes. Continuing up the
path leads to exposures of the Kidderminster Conglomerate which are
excellent for close study. |
via public footpaths |
RIGS Yes. A 70 metre cliff of Permian Sandstone topped by an easily examined
Lower Triassic Kidderminster Conglomerate combines with a magnificent view.
A geologist's delight! |
Sedimentology/Stratigraphy |
|
0955 |
SO 738 956 |
Rindleford Quarry |
Quarry (disused) |
Lower Triassic: Kidderminster Conglomerate. Mostly the sandy facies |
Long vertical wall of former quarry near Rindleford Mill. |
At first glance this sandstone could be mistaken for aeolian but a closer
look at the low angles of cross-bedding the scattered pebbles and the more
angular quartz grains will identify it as being fluviatile. There are no
beds of conglomerate visible at this point but the strata belongs to the
Kidderminster Conglomerate Formation. This is an extensive site (at least
100 m in length) and the faces 9 m high. The quarry exploited a thick
coherent bed of nearly pure sandstone within the Pebble Beds. |
Beside public footpath |
RIGS Yes. Excellent fluviatile features and located near similarly excellent
aeolian sites in Bridgnorth (as at Castle Hill gardens). The section brings
out well the difference between aeolian and fluviatile deposits. |
Sedimentology/Stratigraphy |
|
0956 |
SO 733 958 (SO 732 958 on GIS) |
Worfe Bridge - Worfield |
Cutting (road/railway) |
Triassic (Kidderminster Conglomerate) over Permian (Bridgnorth Sandstone);
Toghill 1990. Map out of date regarding nomenclature. |
Just part of a roadside cutting from which the relief rises abruptly. |
On the west side of the road north of the Worfe Bridge a cut section shows
cross-bedded dune Bridgnorth Sandstone with an undulating erosion surface
dipping gently to the NE. Above this is Kidderminster Conglomerate (1 m
thick) with clasts up to cobble size which fill hollows in the erosion
surface. The beds above are intermingled coarse pebbly cross-bedded
sandstone and conglomerate lenses. This is a very informative site. On the
east side of the road similar features occur but not so clearly. However
here the conglomerate itself is truncated by a major parting with an erosion
surface dipping 5° N cutting through this basal surface. This section
continues south with over 100 m of interleaved cross- tangential- and
trough-bedded sandstones. |
Beside A442. Limited parking near Worfe Bridge. |
RIGS Yes. Clear demonstration of transition from aeolian deposition of pure
sand to fluviatile deposition of mixed sand and pebbles. Also features of
dune deposition are clear. A good site for teaching although the main road
makes large groups impossible. |
Sedimentology/Stratigraphy |
|
0958 |
SO 739 902 |
Quatford (Little Chef) - Quatt Malvern |
Cutting (road/railway) |
Permian: Bridgnorth Sandstone. Toghill 1990. Nomenclature out of date on
Sheet 167. |
Vertical cliff. |
There are 200 m exposing dune sandstone. At the southern end is a steeply
inclined dune structure apparently dipping south and truncated sharply by
planar beds which apparently dip north at varying angles. The section is
impressive as are so many of the sandstone cliffs in the vicinity. It
reaches a max. height of approx. 10 m. Further north the face is more broken
but more steeply inclined dune beds are visible. The cliff section
demonstrates westwardly migrating sand dunes. |
Best viewed from the carpark of the Little Chef and the grass verge opposite
the cliff section. It is possible to walk along the foot of the exposure but
the scale is best appreciated from a distance. |
RIGS Yes. Shows truncation and overlap of cross-bedded foresets within
westerly migrating sand dunes. |
Stratigraphy/Stratigraphy |
|
0960 |
SJ 542 133 |
Haughmond Hill (S) - Uffington |
View |
N/A |
Viewpoint on south-facing slope of Haughmond Hill |
Views here are extensive and a geological panorama is presented. It is an
ideal spot to see the Wrekin; Clee Hills; Church Stretton volcanics; Wenlock
Edge; Long Mynd; and the Welsh Mountains. The site presents an excellent
opportunity to relate landscape features to the underlying rocks. The
immediate foreground is the southern tip of the North Shropshire Plain and
the Shrewsbury Coalfield area. |
Public footpath |
RIGS Yes. Designation because of the range of Shropshire geological features
clearly visible can hardly be surpassed; and the relationship between rocks
and relief can clearly be demonstrated. |
Geomorphology/Landscape |
|
0962 |
SJ 543 134 |
Haughmond Hill Trig. Point |
Crag |
Precambrian basaltic intrusion |
Forms a rounded ridge summit at the highest point of Haughmond Hill (152 m). |
The summit exposes a WNW-ESE dolerite dyke beneath and around the trig.
point. The rock is a medium crystalline greenish dolerite. As is usual with
basic intrusions; the surface weathers brown. Within the dolerite are
discontinuous; whitish; small veins; up to 10 mm across. They show alignment
in a NNE/SSW direction. Under a hand lens these veins seem to consist of
quartz and a black; bituminous material. It is possible that they represent
infilled tension gashes. |
Along publicly used track. |
RIGS Yes. Designation because this site demonstrates a good example of a
Precambrian dyke forming the summit of Haughmond Hill; the trend can be
measured and there are interesting details e.g. possible tension gashes. |
Mineralogy/Petrology |
|
0963 |
SJ 543 149 |
Haughmond Hill (N) - Uffington |
Track/roadside |
Precambrian: Wentnor Group: Bayston-Oakswood Formation: Darnford
Conglomerate. Sheet 152. |
On NW flank of Haughmond Hill as the land goes down to the River Severn. |
This site has potential but in June it is difficult to examine the rock
closely. However; as is typical of Haughmond Hill; the strata are vertical.
The Darnford Conglomerate is displayed as an attractive green/purple rock
with pebbles which here are smaller than in some other places; most clasts
are to be measured in millimetres. It could be described as pebbly grit.
According to Pocock; 10% of the pebbles are igneous. An interesting feature
to be seen at this site is a smooth surface dipping at only 45° and not
consistent with the dip or its immediate surroundings. Although this could
be a joint it was thought more likely to be a small fault plane. |
By the side of B5062 and thus easy to reach. |
RIGS Yes. RIGS designation especially in association with site SJ544419 but
attention is needed before recommendation is proposed. At the moment it is a
good LIGS because of the relatively easy access to what is a limited outcrop
of one of the important conglomerates within the Bayston-Oakswood Formation. |
Sedimentology/Stratigraphy |
|
0972 |
SJ 619 049 |
Leighton |
Stream/brook |
Quaternary: landscape affected by fluvio-glacial action |
Floodplain of the Severn featuring striking meanders |
This is a geomorphological site. The meanders on the Severn in the flood
plain here are outstanding. Sometimes they disappear under flood water which
covers the whole valley but usually they can be seen in the context of the
Severn valley; the mouth of the Ironbridge Gorge and the hills flanking the
valley. In particular; there is a mature meander with a narrow neck; almost
ready to be cut off to form an ox-bow lake. The narrowing of the valley as
it approaches the Ironbridge Gorge is clearly seen and the first of the
river terraces can just be made out from the view-point. |
Visible from viewpoint at parking place by public road |
RIGS Yes. Designation because the valley here demonstrates lateral erosion
and deposition by the river as it builds up its flood-plain. This is also
the place where ice-dammed waters accumulated and fluvio-glacial sands and
gravels were deposited prior to the cutting of the Ironbridge Gorge. It is a
unique and striking section of the Severn Valley. |
Geomorphology/Landscape |
|
0974 |
SO 484 965 |
Comley Quarry - Cardington |
Quarry (disused) |
Cambrian: Lower Comley: Lower Comley Sandstones and Limestones. Sheet 166. |
On lower ground at N end of Little Caradoc. |
The best known section through the L. Comley Sandstone where green
glauconitic medium textured sandstone is seen dipping at 73° E. The type
section of the Lower Comley Limestones is at this site; a detailed
description of the divisions is referred to in Hains. There is a discrepancy
between what is supposedly present in this quarry and what is readily
visible; such is the extent of deterioration. Anyone visiting the quarry
even with some geological knowledge will be greatly disappointed and is
unlikely to be able to identify the horizons described. |
Is open to public road |
RIGS Yes. Designation because of its undoubted importance as the type
section for the Lower Comley Limestones. Also the place where Lapworth
discovered the first L. Cambrian trilobite. However these scores are based
on what is supposed to be there. A student group would no longer find this
site interesting or helpful! |
Fossils and Sedimentology/Stratigraphy |
|
0977 |
SO 477 918 |
Soudley Quarry |
Quarry (disused) |
Upper Ordovician: Caradoc Series: Horderley (Soudley) Sandstone Formation:
Alternata Limestone Formation: Cheney Longville Formation. Sheet SO 49. |
Quarry on the scarp slope of the SE-dipping Caradoc series; E of Soudley
Brook. |
A massive face of Soudley Sandstone rises abruptly at the back of the old
quarry. Bedding is difficult to identify. The distinctive stripes in the
sandstone are easy to see although they are not as purple as seen in
buildings; probably due to weathering. Some fallen blocks are over 2 m thick
and crinoids are visible in places. The angle of dip is approx. 12° SE.
There is a clear break about two-thirds up the face which appears to be the
boundary with the overlying alternata Limestone; this is moss-covered and
packed with brachiopods; mostly decalcified. This boundary is almost
inaccessible and dangerous to reach. Greig describes the alternata Limestone
as '3 ft 3 in. of green mudstone; generally silty and shaly; with 3 bands of
shelly limestone; 4 to 5 in. thick'. Pieces of the shelly limestone can be
found at the foot of the face. Below the boundary; the Soudley Sandstone is
rather broken and above the strata consists of thinner beds; which then
become thicker up the face. The strata above the alternata Limestone belongs
to the Cheney Longville Flags but it isn't safe to examine them in situ. A
section through the strata is described in Greig; p.129. |
From public footpath entry to quarry is easy but examining the upper faces
is difficult and dangerous. |
RIGS Yes. The only contact in the area between the alternata Limestone and
the Cheney Longville Flags. Also the brachiopod Heterorthis alternata was
first defined from specimens collected at this locality as were several
trilobite species. |
Fossils and Sedimentology/Stratigraphy |
|
0984 |
SO 490 956 |
The Wilderness - Cardington |
Quarry (disused) |
Ordovician: Caradoc Series: Chatwall Sandstone. |
Along the Wilderness sandstone ridge. |
Here exposures are limited by grass and nettles but are visible and able to
be examined to some degree. The dip is steep (about 70° or more) and the
sandstone is khaki in colour and medium grained. At the best exposure the
strata can be seen to be dipping nearly vertically along a well-defined
bedding plane. Here the rock is fossiliferous with good examples of
brachiopods e.g. Sowerbyella and Kjaerina. In a hollow on the west side of
the ridge are many loose fragments and larger blocks of a variety of rock
types including red Triassic sandstone and igneous rocks e.g. dolerite.
These presumably are glacial erratics. |
Beside public right of way in pasture |
RIGS Yes. Exposure showing the presence of Alternata Limestone on the crest
of the Chatwall Sandstone escarpment. There are better exposures of Chatwall
Sandstone but this is an accessible site with the fossiliferous interest and
the excellent erratic material. In the light of the demise of the nearby
Netchley Quarry this could be developed into a replacement. |
Fossils and Sedimentology/Stratigraphy |
|
0988 |
SO 505 942 |
Hillend - Cardington |
Natural exposure |
Cambrian: Wrekin Quartzite resting on Uriconian Quartz Porphyry. Sheet 166. |
A sharp SW-trending quartzite ridge lies along the strike |
A prominent exposure of white sugary rock which stains black or brown with
weathering. The strata dip steeply from 40°-50° SE. Texture is slightly
coarser towards the base and irregular jointing leads to a brecciated
appearance. Principal joints at 25° just E of N. There is some quartz
mineralisation on the surface showing slickensiding on the west side of the
ridge. The quarry at the north end of the ridge is used by the farmer and
not accessible. Although there is quartz porphyry underlying the quartzite;
exposures are hard to find and the evidence comes from fragments at the
surface on the west of the ridge top which show a pink feldspar-rich rock
with quartz crystals in a finer groundmass. |
On private rocky pasture sitting above the public footpath. The substantial
quartzite quarry at the village end of the hill is used for farming
purposes. |
RIGS Yes. Designation because the Wrekin quartzite is exposed very clearly
and sharply as a distinctive edge visible for miles and forms a limited
Cambrian exposure outcropping between two E-W trending faults. The
underlying intrusion of quartz porphyry (especially if a small exposure
could be revealed) is also interesting.. |
Mineralogy/Petrology |
|
0989 |
SO 512 936 |
Gilberries Farm |
Stream/brook |
Silurian: Llandovery Series: Pentamerus Beds. SO 49. |
In the valley of Heath Brook; east of Cardington Hill. |
Exposure is about 10 m long and up to 1 m in height; including above and
below water level. The bank is higher but is mostly covered with soil and
vegetation. The rock occurs as discontinuous slabs; is grey; fine-grained
and shaly and is overlain by glacial till. A little further downstream the
colour becomes purplish and some horizons are limy and very fossiliferous
with a mainly brachiopod fauna e.g. Pentamerus oblongus. The dip is 10°-19°
SE. |
In brook bank beside public footpath. Wellies are advisable to gain close
up access. |
RIGS Yes. Designation because this is a good exposure of Pentamerus Beds
which is reasonably accessible. Such exposures are not common in this area
and the site has potential for study. The typical fossil fauna can be seen.
Glacial drift cover is also clearly visible here. |
Fossils and Sedimentology/Stratigraphy |
|
0991 |
SO 539 927 |
Longville to Stanway Road - Rushbury |
Track/roadside |
Silurian: Wenlock Series: Farley Member: Coalbrookdale Formation |
NW-facing scarp slope of Wenlock Edge. |
Several exposures from the foot of the hill to the top are exposed in a road
cutting which rises steeply from the road itself. Alternating fine grained
limestones and buff mudstones were easily visible; thickness of beds varyies
from 25-70 mm. The mudstones are weak and disintegrating. Taken to be
representative of the Farley Member. However although the base of the
overlying Much Wenlock Limestone is described as 'sharp' and occurring where
the first continuous and regular limestone bed appears this was far from
clear. Signs of nodular beds higher up in the sequence were seen. There is a
profusion of vegetation obscuring the exposures and the site has clearly
been deteriorating. There was a distinct difference between what was
actually observed at this site and what can be seen according to the
literature. |
Beside public road |
RIGS Yes. Already a geological SSSI. The SSSI report points out that these
exposures allow correlations to be made between Shropshire's standard
sections for the Wenlock and overlying Ludlow Series. Graptolites found here
have been instrumental in dating the base of the Wenlock Limestone. In
addition their presence has provided a correlation between the base of the
Wenlock Limestone of Wenlock Edge and that of the Ludlow anticline. This
correlation is based on the presence of the graptolite Monograptus ludensis
which was once taken to be an indicator of the base of the Ludlow Series. |
Sedimentology/Stratigraphy |
|
0994 |
SO 573 987 |
Hughley Brook - Gippols Dingle (SW) |
Bank |
Silurian: Wenlock Series: Wenlock Shales: Buildwas Formation. Sheet 152.
Between Harley and Hughley the brook is considered the type area for the
Buildwas Formation. |
At confluence of Hughley Brook and a tributary from the NW. |
A good exposure of alternating blocky (250 mm thick) horizons and slightly
recessed softer layers (150 mm). The exposure is 3-4 m high and extends 10 m
in length. The thinner layers consist of olive shaly mudstones with abundant
tiny fossil fragments (even complete specimens) but (although crammed in the
rock) they are not easily identifiable except with expert knowledge. The
resistant blocky layers are hard and crystalline mid-grey in colour and
clearly calcareous. At the base of the exposure the shales become more
tabular and lime-rich. The strata dip at about 20° SE. This exposure is the
most calcareous of the ones seen in the locality. |
On private land down tributary of Hughley Brook; 10m W of public bridleway |
RIGS Yes. Designation because this is an excellent example of the Buildwas
Formation within its type area; one which can be studied easily and close to
a public bridleway. |
Sedimentology/Stratigraphy |
|
0996 |
SO 5855 9955 |
Rowley Farm (WSW) - near The Gippols |
Stream/brook |
Silurian: Wenlock Series: Buildwas Beds. Sheet 152. |
On the bank of Harley Brook on the lower land between Kenley Ridge and
Wenlock Edge in Apedale. |
The brook exposure on the outside of a meander is 5 m long up to 0.5 m high
and also goes below water level. Small limestone nodules are found both here
and scattered upstream. The rock consists of a grey fine-grained weak shale
which includes fragments of very small brachiopods. |
Near public footpath. |
RIGS Yes. Designation because this is a valuable site providing information
for establishing the Llandovery/Wenlock boundary along the brook and should
be studied with other sites nearby. |
Sedimentology/Stratigraphy |
|
1000 |
SJ 256 298 |
Racecourse Quarry - Oswestry. |
Quarry (disused) |
Carboniferous: Namurian: Cefn-y-fedw Sandstone (Millstone Grit) |
|
Old quarry with much undergrowth; some limited sections currently
accessible. Beds of variable sandstone - very hard to very soft; thick to
thin layers of fine-grained to coarse and pebbly sandstones. 9 m wide X 10 m
high X 5 m deep. Brown to cream variable quartzitic silts; sandstones &
grits. Some beds appear to be chert cemented. Also leached or decalcified
layers with fossil casts. Casts of productus sp. and spirifer sp.
brachiopods. Quartz predominant; some calcareous cemented sandstones. Dip
25° E. Part of huge deltaic complex of Millstone Grit deposited in shallow
water high energy environment. |
From Oswestry take B4580 to Rhydycroesau; at cross-roads after 2 miles take
left turn sign-posted Racecourse Car Park. After 3/4 mile fork right |
RIGS Yes. Part of the huge deltaic complex of Millstone Grit deposited in
shallow water high energy environment. |
Fossils and Sedimentology/Stratigraphy |
|
1001 |
SJ 265 213 |
Pen-y-Foel Lane - Llanymynech. |
Cutting (road/railway) |
Ordovician: Caradocian |
Exposure is on 'leeward' side of roche moutonée |
Dark greenish-grey partly indurated shales with thicker (up to 150 mm)
flaggy sometimes micaceous and/or silty mudstones. Poorly developed jointing
seen in places. A new exposure 5 m X 2 m and unweathered appeared in October
1996 with similar lithology 30 m wide. New exposure yielded several
brachiopods and indeterminate fossils; dip 78° NE (on S. flank of Berwyn
Dome). Close to unconformity with overlying Lower Carboniferous.
PALAEOENVIRONMENT: Deep water facies on fringe of Welsh Basin. |
From cross-roads in Llanymynech take Oswestry road but fork left after 250
m. Exposure is then 120 m along lane. |
RIGS Yes. Good section of Caradoc mudstones |
Sedimentology/Stratigraphy |
|
1004 |
SJ 275 255 |
Savin railway cutting |
Cutting (road/railway) |
Carboniferous: Namurian: Millstone Grit (Cefn-y-Fedw sst.) |
Small fault scarps; well delineated; a short distance north along SJ27752560
- SJ27902600 (L). Also see Geol. Survey map Sheet 137 |
A series of intermittent exposures of variable hard to soft sandstone and
siltstones with some shaley partings. Some quarrying and enlargement of the
cutting on east side. Total section along FP extends from 120 metres to 260
metres from road access point. There are two main locations: (a) 200 m north
of road and (b) 120 m north of road. Further intermittent exposures of
sandstone and siltstone between. Locality 'a' has good exposures of hard
white fine-grained sandstone with some calcareous bands and appears to be
leached in places. Beds vary from thin (20-30 mm thick) to thick (1 m). At
south end can be seen an undersurface of a reddish-brown hard rounded pebble
bed. Locality 'b' has fewer features; mainly massive white fine-grained
sandstone with some … (entry incomplete) |
From A5 from Shrewsbury then B4396 to Llynclys crossroads at SJ282241.
Continue over on A495 for 1 km; turn right at Whitehaven on minor road for
about 1 km northwards; passing 'Sweeney Fen' on LHS. Take first turning left
along lane for 200 m in dip and park on narrow verge just past cottage on
RHS. Parking space is very limited. Footpath is ROW; some minor dumping.
Access is via ROW as marked on SJ22/32. |
RIGS Yes. The Savin Railway Cutting is designated a RIGS as the most
complete section available of the lower Cefn-y-Fedw Sandstone in NW
Shropshire; and for its demonstration of marginal deltaic sedimentation and
diagenetic processes with relevance to educational and scientific studies.
Itinerary; education; schools especially re- local interest use. |
Sedimentology/Stratigraphy |
|
1006 |
SJ 353 146 |
Alberbury Road cutting |
Cutting (road/railway) |
Permian: Alberbury Breccia (ref.1); Permian: Bridgnorth Sandstone |
Cutting is through ridge formed of more erosion resistant rocks; this ridge
may be truncated by faults |
For much of its length the sides of this cutting are obscured by vegetation
and only at the western end are there visible and examinable exposures.
These hint at the potential hidden beneath the vegetation cover. On the
south side is a good section of red fluviatile sandstone; fine grained with
with fine cross laminations. At its top is a clear erosion surface with a
small wash-out and this in turn has an eroded top to be succeeded by a
coarse grain stone which leads upward into mixtures of sandstone and
conglomeratic breccia. Dip is to the north-east and the section is partly
replicated on the north side with thick fluviatile sandstone and lenses of
conglomeratic breccia. Also on the north side there is a down-faulted block
of paler pebble free sandstone; 3 metres wide; suggestive of the overlying
aeolian Bridgnorth Sandstone. Cutting is 130 metres long and; on average 4
metres high. Exposure at west end on south side is 10 metres wide and 4
high. Exposure on north side is 15 metres long and 4 high. No fossils found.
Uniform dip ca. 15° NE. |
On main road heading west through village. There is considerable danger
within the cutting from passing traffic; only the section on the south side
at the western end can be safely examined. Limited parking |
RIGS Yes. The cutting designated a RIGS for its potential as a site showing
the sedimentary features of a high energy fluviatile regime so demonstrating
the extensive and rapid erosion which must have taken place at the end of
the Carboniferous period. |
Sedimentology/Stratigraphy |
|
1007 |
SJ 360 143 |
Alberbury |
Track/roadside |
Permian: Alberbury Breccia (ref.2); Carboniferous: Erbistock Group:
Alberbury Breccia (ref.1) |
The Alberbury Breccia and associated rocks; being relatively erosion
resistant; form a marked E-W ridge between Alberbury & Rowton. This has a
stepped cross-section reflecting effects of softer strata according to ref.1 |
The southern edge of the car park exposes a well bedded and distinctly
tabular sequence of dark red weathering breccia. Individual blocks are
widely deployed in the old stone walls for walled garden, houses and the
church. |
Centre of village just north of Shrewsbury road. Car park by village hall;
permission should be sought |
RIGS Yes. This location designated a RIGS as the most easily accessible
exposure of the distinctive Alberbury Breccia which so clearly demonstrates
the extensive and rapid erosion which must have taken place at the end of
the Carboniferous Period. Potential use for small parties with supervision. |
Sedimentology/Stratigraphy |
|
1018 |
SJ 610 102 |
Overley Hill |
Cutting (road/railway) |
Precambrian: Uriconian; rhyolites |
|
Construction of the A5 by-pass has created a road cutting revealing 100
metre long and 3 metre high sections in Uriconian Rhyolites. The faces are
fresh and unweathered and show fine texture and a 3-D ramification of slip
and joint planes. The exposures are within the same fault block as that of
the Lea Rock inlier described as red and purple rhyolites with flow-banding
and spherulitic structure. In conjunction with the near-by Leaton Quarry
this site relates to the Precambrian rhyolite/tuff fabric of the Wrekin
hill. Report of 15/01/2002 (Christine Rayner): A relatively fresh exposure
of mainly pink rhyolite with some grey tuffs; often brecciated along
fracture zones. The north side was examined as the south was in dense shadow
with detail hard to see. The rhyolite displays excellent flow-banding and
spherulitic structures have been recognised in the rock. The exposure is
broken by much faulting as well as the shattering due to excavation for road
construction. Much slippage is evident; resulting from the position of the
exposure in a fairly narrow fault zone; part of the Church Stretton fault
system. Many near parallel faults can be identified and also larger; curved
sheared surfaces. Slickensiding occurs as do a number of near vertical
mineral veins which appear to contain barytes with hematite; the latter
giving a purple hue to the surfaces in places. The exposure demonstrates a
series of bedded lavas; the dip being at 40° SW. |
By way of the ‘Shropshire Way’ official public foot-path which crosses the
A5 by-pass at the eastern end of the cutting. Some danger from proximity of
fast moving traffic; at quiet times a vehicle could be parked |
RIGS Yes. A conspicuous road-side feature on the A5 by-pass showing the rock
(rhyolite) of which the Wrekin Hill (dominant on the sky-line to the south)
is mainly composed. The site designated a RIGS in recognition of a
latter-day aesthetic juxtaposition. The site has intrinsic worth for the
freshness of its exposures which clearly demonstrate the internal shattering
which takes place in a large viscous rhyolite lava flow as it slowly cooled
and solidified to a brittle glassy consistency. |
Mineralogy/Petrology |
|
1020 |
SJ 638 027 |
Ackland's Coppice |
Track/roadside |
Silurian: Tickwood Beds and Wenlock Limestone. Dip 5° SSW. Apparently
conformable transition between stages |
Deeply incised stream just to south |
The lower 15 metres of the section shows grey argillaceous limestone
weathering brown. This is generally massive but irregularly bedded with a
nodular component. There are a number of distinct shale bands; one of which
lies immediately above the pronounced terrace which has been engineered at
mid-height. Some strong joint planes are present cutting across nodules.
Only a sparse fauna is present. The terrace is cut just below the thickest
of the shale bands - some 250 mm. Above; the limestone character changes to
become distinctly crystalline although still nodular and irregularly bedded.
This limestone is notably fossiliferous; especially a scattering of large
corals. It is here considered that the terrace marks the transtion between
lower Tickwood Beds and Wenlock Limestone. 170 m wide; lower part 15 m high
to terrace; above terrace 4 m of rock then 10 m graded slope. Sparse
brachiopods & trilobites in Tickwood Beds. Rich fauna of corals;
strophmenoids; gastropods; etc in Wenlock Limestone. |
Along the A4169 Much Wenlock to Buildwas road; about mid-way along the newly
excavated cutting |
RIGS Yes. The site designated a RIGS for its vivid demonstration of changes
in lithology and fauna between Tickwood Beds and overlying Wenlock Limestone
facies within the Wenlock Series; for which this general area provides the
International Standard. (It may provide a substitute for the SSSI of Farley
Dingle insofar as this was affected by the recent road-works.) Itinerary;
A-level studies; limestone environments & fossils |
Fossils and Sedimentology/Stratigraphy |
|
1022 |
SJ 643 096 |
Ercall Hill |
Quarry (disused) |
Precambrian: Uriconian Volcanics. Cambrian: Wrekin Quartzite: Comley Beds |
Ercall Hill 65m |
At the southern end of the Ercall are 5 quarries; now disused; which are of
great geological interest. The unconformity between Cambrian and Precambrian
rocks is exposed. Radiometric dating of the latter; particularly the
granophyre; generates controversy about the absolute age of the base of the
Cambrian. A variety of igneous rocks; rhyolite lavas and pyroclastic
materials; dolerite dykes and the distinctive pink boss-like intusion of
granophyre are exposed. The sedimentary rocks include conglomerates; breccio-conglomerates;
quarz arenites and glauconitic sandstones/siltstones of Lower Cambrian age;
typical of a sequence deposited during a marine transgression. The upper
quarries provide excellent opportunities to examine rock relationships;
fault; joint structures and dip/strike. Many smaller scale sedimentary
structures can be observed; e.g. ripple marks; cross bedding; fining-upward
sequences. Igneous flow-banded and spherulitic structures are present in the
rhyolite. In addition to the quarries which are a SSSI; the rest of the
Ercall is of geological importance. At the N end; close to the M54; small
exposures of rhyolitic tuffs can be seen and persistent searching on the
hillside to the west of the main footpath brings evidence of white kaolin
clay weathered from feldspar in the igneous rocks. Car parking areas on the
west side make use of small former quarries in the granophyre. The view
points at the top of the hill by the main footpath provide the opportunity
to relate the Ercall rocks with the younger rocks to the east. |
Open access. Car parking at the Forest Glen opposite the Wrekin but there
are small car parks along the west side. |
RIGS Yes. An outstanding locality with easy access designated a RIGS in its
entirity as it exemplifies a range of rocks and structures reflecting a
calcalkaline volcanic environment and subsequent marine transgression. Even
more important are the visible exposures of the Precambrian/Cambrian
unconformable boundary. Good for large parties. Scope for varying levels of
interpretation. Useful for a study of rock relationships and a range of
igneous and sedimentary rocks /structures. |
Structure and Sedimentology/Stratigraphy |
|
1047 |
SO 310 740 |
Holloway Rocks - Stowe |
Natural exposure |
Silurian: Rhychonella and Chonetes Beds of Stamp (ref.1). Silurian:
Whitcliffe Beds or Cefn Einion Formation of current nomenclature |
Glacial features including moraines; incipient corrie formation; hanging
valley and moraine dammed pool |
The locality comprises about 1 sq.km of hillside best examined from the
public bridleway leading from Stowe Church to Holloway Rocks. Between the
church and the first gate are numerous small exposures in bioturbated grey
siltstone which show mainly Fuchsella & Camarotoechia and correspond to
Rhynchonella beds of Stamp (ref.1). Past the gate a quarry gives good
examples of typical fauna of these beds with Serpulites longisimus
particularly prevalent and Protochonetes ludloviensis specifically absent.
The track then ascends steeply to a second gate and stile beneath the steep
slopes of Holloway Rocks. Here the rock now shows the full complement of
brachiopods typical of Upper Whitcliffe beds in this area; viz.
Protochonetes; Camarotoechia & Salopina lunata; these beds now continue
right to the summit of Stowe Hill above where they are; again typically;
yellow weathering. It is from the position of the stile that the glacial
features may best be appreciated. The frost-shattered exposures of the scarp
above which sweeps round towards the west suggests the early stages in
corrie formation; hidden around a corner; also to the west; is a small
stream whose bed has been truncated to form a hanging valley feature. Most
notable are the crests of three distinct moraine ridges which trend SW
towards the main valley of the River Teme below (various moraines impinge
upon the road in this valley and a good section of morainic material can be
seen in the bank excavated behind Mill House at SO310729). Behind the three
moraine ridges is a small perfectly circular pool (at SO311742) evidently
impounded behind these moraines on the ‘corrie’ floor. Overall the view
southwards from here is impressive. The hills across the river valley occupy
ground mapped by Holland in the 1950's (ref.2); in particular the
observatory identifies Llan wen Hill which provides the type section for the
uppermost Whitcliffe beds in this area. Geological Summary (with keywords).
Lithologies: siltstones; occasionally calcareous. Palaeontology: limited
fauna of brachiopods; bivalves; orthocones and (Serpulites). Structure:
bedded strata dips gently to NE forming a scarp feature; this has been over
steepened with beginning of corrie and hanging valley formation.
Palaeoenvironment: sediments laid down on shelf/basin slope below wave base
but shallow enough to suffer bioturbation and to accumulate some allogenic
fauna. |
Best from Stowe Church adjacent to which is a car park. Access via public
bridleway. |
RIGS Yes. The area designated a RIGS on account of its clear demonstration
of the principal glacial features of corrie and moraine with obvious
relevance to recent ice ages. It also displays an informative section
through a 150 metres thickness of shelf slope sediments. |
Fossils and Sedimentology/Stratigraphy |
|
1050 |
SO 318 837 |
Hoar Wood - Bury Ditches - Clun |
Track/roadside |
Silurian: Cefn Einion Formation and Clun Forest Formation (ref.1); Silurian:
Upper Whitcliffe and Downtonian; Silurian: Upper Ludlovian and Pridoli |
|
The section forms the east bank of a roughly N-S track. The dip is to the
south and the section is best examined in ascending sequence from north to
south beginning at a pronounced bend in the track. Just to the east of this
a small quarry shows typical bioturbated and rather featureless grey
siltstones of the Cefn Einion beds. In distinct contrast the first exposure
of the section is of sheet-like deposits of allogenic fossils which include
brachiopods; gastropods; trilobites and occasional ostracodes. The next 200
metres expose a rich sequence of bedded units showing sole marks; rippling;
erosion surfaces all indicative of a high energy environment which was
probably above storm and/or wave-base and shallowing. There then occur a
number of horizons containing Platyschisma & Modilopsis; one bed of the
former forming a thick rotten stone. These mark the base of the Downtonian
and over the next 50 metres is a development of very calcareous beds
approaching an actual limestone in composition. Continuing on; a small
hiatus intervenes due to faulting and then there is a quarry exposing well
bedded Downton Castle Sandstone; with small flecks of plant remains visible
on bedding planes. Following the track which has now turned SE; the
sandstone becomes more massive and then is succeeded by a hard siltstone;
which may represent overlying Temeside Shales although this has not been
confirmed. Overall section is 500 metres long and typically 2 to 3 metres
high. |
Open access within a Forestry Commission area. By well made forest tracks
and foot-paths. Nearest parking is at Colstey on A488 Clun to Bishop's
Castle road |
RIGS Yes. This section; with its easy accessibility; designated a RIGS as an
exemplary example of the Silurian Ludlovian/Downtonian transition;
particularly rich in fossil and sedimentary features. |
Fossils and Sedimentology/Stratigraphy |
|
1051 |
SO 323 933 |
More Quarry (older) |
Quarry (disused) |
Ordovician: Hope/Stapeley Beds of Llanvirn Series; intruded by dolerite
(?gabbro) |
|
Among the late Ordovician intrusions this area to the east of the More
Quarry was previously an SSSI (ref. 4). The site is a small quarry to the
west of the disused but dangerous main quarry. It is notable for the
extended contact feature showing a 150 mm chilled margin of the massive
coarsely crystalline dolerite(?gabbro) and hardened country rock. The latter
is Hope Shales and/or Stapeley Volcanics. There are suggestions in ref(1)
that the intrusion may be overlain by Silurian. Some variation in the
identity of intrusive rock variously described as gabbro; dolerite or
gabbroic dolerite (ref. 2); margins are chilled. No fossils found; the area
of the descheduled SSSI to the east of the main quarry is described as
fossiliferous Hope Shales (ref. 3). Massive intrusion of indeterminate form;
slickensides. Baking of country rock; chilling of margins. |
Via A488 to point about 2 km N of Lydham. Limited parking on E side of A488. |
RIGS Yes. The site is designated a RIGS as a good and well displayed example
of the features developed in the contact zones between a large igneous
intrusion and sedimentary country rocks. It also provides a specific example
of one a number of large basic intrusions which occur in this area; notably
the Laccolith of Corndon Hill and the Picrite of Cwm Mawr. |
Mineralogy/Petrology |
|
1055 |
SO 375 942 |
Upper Gravenor - Wentnor |
Quarry (disused) |
Dolerite intrusion within Precambrian: Wentnor Series |
|
The quarry is excavated in a large linear intrusion of dolerite which can be
traced up the hill to the west for a distance of 0.5 km. The intrusion
cuts across the dip of the fine sediments of the Bridges Group and is
therefore probably a dyke (ref. 1) albeit quite thick. The quarry has an
unusual form having been excavated as an L-shaped cutting some 3 to 4 metres
wide and up to 5 metres deep. The freshest rock is massive fresh and
crystalline and is exposed on the left wall of the excavation. It appears to
contain large 1 metre scale xenoliths of country rock which are clearly
baked to a black colour. Similar xenoliths appear in the right wall but in
the furthermost part of the ‘L’ this side shows the dolerite in a different
form. A a slope appears with many apparently spheroidally weathering
boulders irregularly disposed of different sizes and not obviously related
to any jointing pattern. The boulders are the result of deep chemical
weathering (possibly Tertiary in age). In other parts there is developed
curvi-linear columnar jointing chilled margins and country rock xenoliths. |
From B4383; 2 km south of Bridges cross-roads; take a minor road SSW |
RIGS Yes. The quarry designated a RIGS as an exemplar of an intrusion; both
baking and incorporating xenoliths of country rock as well as showing
features of columnar jointing chilled margins and spheroidal weathering. |
Mineralogy/Petrology |
|
1060 |
SO 391 874 |
Hillend (West of Farm) |
Track/roadside |
Precambrian: Synalds Group of Longmyndian - Purple shales; Silurian: Upper
Llandovery; conglomerate and grit. |
Small exposure off road at base of hillside. |
The deposition of early Silurian strata on a block of Precambrian sediments
is known from a sequence of exposures between Plowden and Little Stretton.
Mapped in detail by Whittard (1932) who identified features including
sea-stacks beach deposits and pebble bars. The only direct recognition of
this work is a SSSI at Hillend where a quarry in Pentamerus Beds is
designated for its micro- and macro- fauna content (ref. 5). This site (to
the east of the SSSI) convincingly shows the unconformity with Upper
Llandovery age grits which are occasionally fossiliferous resting with
marked discordance on eroded purple shales of the Synalds Group. Fossils
rare in grits; brachiopods in higher beds. Precambrian shales have vertical
dip and strike NE; basal Silurian grits dip ca. 25° S. Strong unconformity. |
Along A489 between Craven Arms and Lydham; ca. 300m. SW of Hillend Cottage. |
RIGS Yes. Designated as the predominent example of the unconformity which
lies at the base of the Silurian in Shropshire and the Borders. It is of
particular value since related exposures to the east allow the demonstration
of a complete stratigraphic column for strata within the Silurian as far as
the cut-off in Wenlock Shales by the Church Stretton fault system. |
Structure and Sedimentology/Stratigraphy |
|
1084 |
SO 421 946 |
Ashes Hollow -Little Stretton |
Natural exposure |
Precambrian: Longmyndian Group: Stretton Series; Stretton Shales; Burway;
Synalds and Portway Groups |
Incised Vee-shaped stream valley with overlapping spurs |
The valley from Little Stretton (SO441920) to Boiling Well (SO421946) is
about 4 km long. There are very many good exposures especially of Burway
Lightspout and Synalds Groups. Overall the best exposures (some 21 in
number) are fully described in an attached document ‘Precambrian Stretton
Series of Ashes Valley Longmynd’ which uses the format of a Geological
Itinerary to effect a description. Features covered include crenulation and
kink bands in the Stretton Shales brecciation and quartz-filled tension
gashes in the Buxton Rock Scree fans; freeze-thaw; possible turbidites and
lamination in the Burway Group; greywacke sandstones of Cardingmill Grit;
rippling; desiccation cracks; cleavage; cleavage refraction and way-up
criteria in Synalds Group; lithic tuff and transverse faulting of vertical
strata in Batch Volcanics; joint planes; cut pebbles; slickensiding and
fault location in Huckster Conglomerate; cross bedding; erosional base and
pick-up clasts in Portway Group. Geological Summary (with keywords).
Lithologies: Indurated mudstones; siltstones; greywacke sandstones;
conglomerate; lithic tuffs and dolerite. Petrology: Greywacke; dolerite and
volcanic tuffs. Minerals: Quartz. Palaeontology: None. Structure: Steeply
dipping limb of a recumbent syncline (ref.1). Relationships: Conformable
sequence of differing lithologies. Palaeoenvironment: Upwards coarsening
sequence; possibly progradational through turbidite; delta; alluvial and
braided alluvial (ref.2). |
From A49 at Church Stretton travel 2 miles to Little Stretton and locate the
‘camping field’ and ford. Open; mainly along public footpath; some over
heather clad slopes. 2 inns in Little Stretton; all other in Church Stretton |
RIGS Yes. Ashes Hollow streamway designated a RIGS as a coherent upwards
coarsening sedimentary sequence through most of the Precambrian Stretton
Series. It displays a wide diversity of features and is well able to support
a geological itinerary. |
Structure and Sedimentology/Stratigraphy |
|
1106 |
SO 444 804 |
A49 Craven Arms to Onibury |
Cutting (road/railway) |
Silurian: Lower Ludlow Shales to Upper Ludlow Shales |
|
South of Craven Arms the eastern side of the A49 cuts through a number of
spurs providing a sequence of exposures from Lower Ludlow Shales through the
Aymestry Group to Upper Ludlow Shales. Distances are given in kilometres
south from cross-roads in Craven Arms and (in brackets) north from level
crossing at Onibury. 2.53-2.73 (1.83-1.63) Lower Ludlow Shales; 3.07-3.27
(1.39-1.19) Aymestry Limestone; much attenuated but good transition to Upper
Ludlow; 3.81-3.91 (0.55-0.45) Upper Ludlow Shales; 4.02 (0.34) Upper Ludlow
Shales in entrance to quarry. Exposures are generally fossiliferous and dip
gently to SE. Conformable sequence. |
South from Craven Arms; parking alongside A49 difficult; best to walk
sections starting from entrance to Park Farm SO406802 just south of first
section. Hazard of passing traffic is serious for groups |
RIGS Yes. This section designated as a RIGS to help ensure its survival as a
very visible section through that sequence of Shropshire's Silurian strata
which determine the topography of a large area of the county. |
Fossils and Sedimentology/Stratigraphy |
|
1109 |
SO 446 899 |
Chuney Pool - Acton Scott |
Bank |
Ordovician: Acton Scott Group below Limestone. |
|
Approaching along the outflow stream-way leading to Chuney Pool this makes
an abrupt left turn to reveal a small ravine with a water cascade at the
end. Both walls of the ravine expose olive-green micaceous siltstone;
dipping c. 20° N. This rock is soft and shows few brachiopod casts and
impressions. 2 faces each 20 m long and up to 4 m high. |
From A49 250 m south of Marshbrook garage (SO442898) take road sign-posted
to Acton Scott. Take foot path immediately behind black and white cottage;
after 50 m turn right and follow stream-way through woodland. Parking at
Marshbrook; Wayside Inn and cafe. Woodland partly used for game birds; some
felling. |
RIGS Yes. Designated as the principle exposure of fossiliferous sediments
within the lower part of the Acton Scott Group. |
Fossils and Sedimentology/Stratigraphy |
|
1112 |
SO 446 961 |
Batch Valley - All Stretton |
Natural exposure |
Precambrian: Longmyndian: Synalds Group (Batch Volcanics). TYPE LOCALITY:
For the Batch Volcanics with the Synalds Group |
|
Four ash bands have been identified within the predominantly purple shales
of the Synalds Group. They outcrop across the ridge which rises westward
from the junction of Johnathan's Hollow and Long Batch; the lowest band also
outcrops continuously along the ridge rising NE from the same junction. In
this latter situation the outcrop well shows the numerous small transform
faults (both dextral and sinistral) which affect the outcrop of the steeply
dipping Longmyndian sediments. As part of this survey the position of the
outcrops of the 4 bands along the western ridge has been remeasured. The
bands are individually described in the table taken from ref.1. Band A (the
Andesitic Ash) forms the lower part of the second rock step at the start of
the ridge. Only the purple facies is visible; the green variant being turf
covered. As the dip is steep to the NW the outcrop cannot be traced further
to the west. The ridge has a trend of 300° and an average slope of about
30°. Ascending its crest band B occurs after 233 ft. (1 foot = 0.30 metres)
and band C after 294 ft. just above the second of a pair of small trees.
Band D outcrops after 401 ft. and the base of the Lightspout Group occurs
after 464 ft. where the angle of the ridge eases somewhat and crags become
much less frequent. Band C (the White Ash) can be traced westward across the
face of the hill as far as the entrance to Long Batch. The NE ridge has a
trend of about 45° and along it band A (the purple Andesitic Ash) can be
traced for about 150 m. Between the 4 ash bands the purple shales often show
a polished fluting decorated with arrays of fine pits which have been
ascribed to rain spots. |
From All Stretton tarmac road leads past Village Hall to car park after 400
m. Thereafter a track continues 800 m to Johnathan's Hollow. The Long Mynd
has open access. Shop Pub and Hotel in All Stretton. |
RIGS Yes. Type Section for the Longmyndian Batch Volcanics; illustrates the
geometric relations encountered in mapping dipping strata in a hilly
environment and for the demonstration of volcanic activity within
Longmyndian times. |
Sedimentology/Stratigraphy |
|
1128 |
SO 459 955 |
Buxton Quarry - All Stretton |
Quarry (disused) |
Precambrian: Stretton Series: Stretton Shale Group; Buxton Rock; Burway
Group. TYPE LOCALITY: Buxton Rock |
|
Mapping of the sequence of Longmyndian sediments has required use of
disitinctive and persistent beds to act as ‘markers’. A siliceous tuff
(green-grey and cherty in appearance) has been used to define the base of a
more arenaceous and flaggy Burway Group over lower and generally incompetent
Stretton Shales. Buxton Quarry provides the type section. The RHS is
dominated by a vertical bedding plane is Stretton Shales (a rock of weakly
bedded and monotonous grey mudstone/fine siltstone). Occasional paler bands
up to 10 mm thick may mark the presence of volcanic ash fall-outs. The main
outcrop of Buxton Rock is in the centre where a rough track ascends steeply
to higher levels. The Buxton Rock is recognised by its cherty texture an
absence of internal bedding or lamination and with a slightly undulose form.
It can be seen to split by shaly horizons into separate units of variable
thickness and at least 8 such beds between 200 and 500 mm thick can be
identified. The rock has been described as a ‘silico-felspathic slate in
concretionary layers’ (ref 4) and as a ‘silicified dust tuff’ (refs 2;3;4).
To the left and in the higher parts rocks of the basal Burway Group are seen
(notably flaggy bedded with units thickness 50 to 150 mm seperated by thin
shale horizons). Slight grading can be detected suggesting younging to the
left (W). Thin pale bands 2-3 mm similar to those seen in the Stretton
Shales are also present. Quarry is roughly L-shaped; 30 m across long base;
20 m across short and up to 25 m high. Silification and quartz veining. No
fossils. Near vertical dipping sequence; strike SW-NE; younging to NW. East
part of quarry shows very large bedding plane and similar outcrops are found
in a lane just to the west. |
In All Stretton take lane sign posted to 'Village Hall'; Quarry is on right
after 200 metres. Ample parking and shop/pub/hotel in All Stretton. |
RIGS Yes. Buxton Quarry designated a RIGS as the type section for the Buxton
Rock; this is a marker horizon for the boundary between lithologically
changing rocks of the Stretton Shale Group and the Burway Group within the
Precambrian of the Longmynd. |
Sedimentology/Stratigraphy |
|
1135 |
SO 468 821 |
Bache |
Quarry (disused) |
Silurian: Upper Ludlow Shales |
Fault scarp |
Quarry lies on a SW facing scarp slope due to the down-throw of the strong
SE trending Bache Fault. The quarry face shows an alternation of massive
siltstone with some current bedding and bands of vertically jointed
calcareous sandstone up to several inches thick. The main feature is however
a 0.7 m thick bed showing a text-book example of slumping. This strongly
resembles a similar feature in the Whitcliffe quarry type section for the
Whitcliffe Stage (ref.3). There are also some lenses of fossil shells now
leached to a ‘rotten-stone’. Face is 30 m long and 4 m high. Brachiopod
casts & shells. Gentle dip; modest jointing with conspicuous slumping. |
From Bache House on minor road between Greenway Cross on B4368 and Burley
take public footpath heading SE towards lake; quarry is situated where this
path crosses a tarmac drive. Limited parking; other in Craven Arms 2 miles
distant. |
RIGS Yes. This site displays a ‘text-book’ example of slump bedding and is
situated on a fault scarp. |
Sedimentology/Stratigraphy |
|
1145 |
SO 474 924 |
Hope Bowdler |
Track/roadside |
Ordovician: Harnage Shales. |
|
By the footpath sign beneath a tree is a small patch of soft brown shale
fragments identified as Harnage Shales. By the gate is what looks like a
small outcrop of hard volcanic rock; if so this would represent the
Harnage/Uriconian unconformity without the development of a conglomerate.
Following the footpath over the stile to the right; the path enters a sunken
way; there is another small outcrop of Harnage Shales 30 m on the left.
Shales are totally fragmented; no in situ exposure. |
150 m south along the Ticklerton road from Hope Bowdler there is a footpath
sign on the RHS (W). Parking in Hope Bowdler |
RIGS Yes. Designation as a major unconformity of Ordovician Harnage Shales
laid down upon a weathered surface of Precambrian Uriconian Volcanics. The
former yields a shelly fauna and significant ostracodes have been found. |
Sedimentology/Stratigraphy |
|
1149 |
SO 475 947 |
Willstone Road Quarry |
Quarry (disused) |
Cambrian conformable junction between dipping Lower Comley Sandstone and
Wrekin Quartzite |
Relative erosion rate of volcanic (rhyolites; tuffs; intrusives) and
unmetamorphosed sediments. |
The ‘quarry’ is now a vertical bank; some 1 m high and 10 m long bordering a
farm-track. To the right are ca. 8 m of buff-coloured fine-grained sandstone
(Lower Comley) whilst to the left are ca. 3 m of grey/white quartzite
(Wrekin Quartzite). The junction between is clearly conformable and strikes
due north with a dip 70° E. Both rock types are undistorted and only
moderately jointed. Uriconian volcanics outcrop on the hillside to the W and
fault F2 is mapped immediately to the NW cutting off the quartzite outcrop.
Cursory examination has failed to reveal any fossils. |
By foot or bike along old road between Willstone Farms (SO491953) and
Eastwood; Church Stretton (SO464940). From Willstone; 500 metres beyond Cwms
Cottage this road makes a left turn from where a public footpath to Caer
Caradoc strikes off to the right (N). Taking this path the site is
immediately seen some 50 m to the right (E). From Church Stretton the same
point is reached some 700 m beyond the defile between Helmeth and Caradoc
Hills. |
RIGS Yes. Comformable junction between the Lower Comley and the Wrekin
Quartzite |
Fossils and Sedimentology/Stratigraphy |
|
1150 |
SO 475 951 |
Caer Caradoc Ridge |
Natural exposure |
Precambrian: Uriconian: Ragleth Tuffs; intruded by a dolerite sill. |
Scarp feature |
200 metres SW of the summit is a low col to either side of which outcrops a
strong linear feature. This is a well-bedded acidic tuff showing small scale
current bedding features. Traced down the hillsides to NW or S it is seen to
be underlain and intruded into by a dolerite. Near the ‘col’ the outcrop
appears finely bedded; weathers to resemble the summit rhyolites in colour
and surface texture; however the ‘bedding’ is much more genuine with beds
varying in thickness and grain size and bedding planes lacking
slickensiding. Interpreted therefore as a bedded acidic tuff; the dip is to
the west around 45°. In detail the bedding shows grading; small folds;
closely spaced jointing and features suggestive of slumping and/or
de-watering. This is best displayed 60 m south of the col. Before that (at
45 m and 55 m) the tuffs can be seen to be underlain by and intruded into by
a dark grey rock identified as dolerite. At 100 m there is clear emergence
of this underlying dolerite forming a sill-like contact with the overlying
tuffs which is displaced up-slope by a small fault to expose the lower
contact. Generally 2 m high extending 200 m to S and 200 m to NW. Structure:
Tuffs dip west around 45° and in absence of significant transverse faults
form a remarkable linear scarp feature. This linearity may be due to a NW-SE
trending fault which separates Ragleth Tuffs from Caer Caradoc Andesites and
has itself been intruded with dolerite (ref.1). |
From summit walk SW 200 metres to a low col. |
RIGS Yes. Well bedded acidic tuff |
Mineralogy/Petrology |
|
1158 |
SO 477 953 |
Caer Caradoc |
Natural exposure |
Precambrian: Uriconian: Caer Caradoc Rhyolite and an Andesitic lava. TYPE
LOCALITY: Caer Caradoc Rhyolite; Caer Caradoc Andesite. |
Differential erosion of hard resistant rocks of Precambrian basement
produced by uplift as a horst. Possible nunatak. |
The summit of Caer Caradoc within the confines of the Iron Age Hill Fort
provides splendid outcrops of rhyolites; variously flow-banded; amygoidal;
brecciated and slickensided. An area of andesite (sometimes amygdaloidal)
and a small intrusion of dolerite can also be recognised appearing to
underlie the rhyolites. The best approach is via the NE ridge where the
change on crossing the fort embankment; from dark grey Little Caradoc
Basalts to large pink and yellow crags of Caer Caradoc Rhyolite is quite
dramatic. At this NE end the exposures display an apparent bedding albeit
much contorted twisted and over-turned. On examination the ‘bedding planes’
are generally slickensided and the ‘bedding’ seems more a consequence of the
flow of viscous acid lavas. Exposures in the actual summit area are
generally massive irregularly jointed and sometimes vesicular. Brecciation
of the flows becomes more conspicous as the rhyolite forms ‘ramparts’ to the
hill fort on the SE side. A zone of vertical banding intervenes before the
‘gateway’ dominated by a large high block of brecciated material. At this
point emerging from beneath the greensward are blocks of fossiliferous
Chatwall Sandstone and Quartzite has also been built into the embankment.
Just west of the ‘gateway’ are exposures of vesicular Caer Caradoc Andesites
which reinforce the impression that the rhyolite forms a comparatively thin
bed. Further exposures continue to the south reaching almost to the foot of
the steep hillside. No fauna within volcanics but Ordovician fauna in
‘erratics’. Structure: Base of rhyolite flow dips towards SW; Caer Caradoc
hill is delineated by strong NE-SW faults and this directional trend can be
seen continuing to the NE to encompass Lawley Hill and the Wrekin. The area
of Caer Caradoc is some 120 hectares in extent; involves 8 individual
stratigraphic rock units and at least 50 individual exposure sites. This was
fully surveyed over the course of several days of late Aug and Sep 2001. In
view of the large amount of data collected it is convenient to use this
‘description’ field to record what may be regarded as the features of most
interest and significance and to append methodology; detail and conclusion
as attachments to this report. Principal features: (1) many exposures of
igneous fine-grained acid and basic rocks; instrusives and lavas; together
with fine grained bedded tuffs. (2) a major unconformity whereby the
Cambrian Wrekin Quartzite overlies a sub-set of the volcanics. (3) major
exposures of rhyolites showing various degrees of auto-brecciation;
slickensiding; flow banding and elongated vesicules. (4) a folded syncline
in bedded tuffs with sufficient exposure to allow dip measurements which
confirm that the syncline plunges NW. (5) visible evidence of doleritic
intrusion in the sense of chilled margins and injection into open joints.
(6) a major and very visible normal fault which crosses the axis of the
hill suffering change of direction of its surface outcrop. (7) other faults
classified as reverse or thrust; in particular exposure of a possible thrust
plane. (8) significant amounts of sedimentary erratics; Cambrian and
Ordovician associated with the hill fort on the summit. |
Footpaths converge on summit from many directions. The footpath up the NE
ridge is not a public right of way. |
RIGS Yes. Exemplar for Precambrian volcanics. Wealth of other geological
features; high scores in all the assessment criteria and scope for a
geological itinerary or trail. Education - scope for field examination of
wealth of features and for practical exercises. Scientific - nothing seems
to have been published since the Geological Survey Memoir (Greig et al
1968). Some unresolved problems remain; so a possible area for research.
Historic - a notable Iron Age Hill Fort with an intriguing geological
problem. Aesthetic - superb view points through 360 degrees. |
Mineralogy/Petrology |
|
1172 |
SO 483 955 |
Robins Tump |
Natural exposure |
Cambrian: Lower and Upper Comley Sandstones and Grits |
Situated in an area of fault-bound blocks in which exposures are few but
differential erosion rates allow for feature mapping. |
The summit of this small but conspicuous hillock shows Upper Comley Grits
dipping east with Lower Comley Sandstones beneath. The Comley Limestones
(which bridge this junction in the Comley Quarry (SO484965)) are absent. It
is the site of one of the many excavations carried out by E.S. Cobbold in
the course of his elucidation of the stratigraphy of the local complex
faulted area. Other excavations were made on the ‘saddle’ to the south and
several near the stream at the foot of the northern slope where Lower Comley
strata are better exposed. No fossils found - may have been picked clean. An
unconformity seperates Lower and Upper Comley strata but this can only be
deduced from the exposures; not seen. |
By paths from the track between Willstone Farm and Cwms Cottage or by paths
from Comley via Hill House. |
RIGS Yes. Designated as a RIGS as the only exposure of the junction between
Lower and Upper Comley strata and as tribute to the work of the geologist
E.S. Cobbold |
Sedimentology/Stratigraphy |
|
1190 |
SO 495 851 |
The Sun Inn (car park) - Diddlebury |
Cutting (road/railway) |
Silurian: Upper Ludlow Shales |
|
Although mapped as Downton Castle Sandstone it is believed that the section
exposed in the lower part of the bank on the north side of the carpark is in
fact Upper Ludlow Shales. This shows blocky buff and yellow silstones with
some false bedding current bedding and slumping visible. There is a sparse
shelly fauna. Higher up the beds become more friable but cannot be directly
observed due to a heavy over-growth of vegetation. The Ludlow Bone Bed could
be expected at this horizon but was not identified. 50 m long and 2 m high.
Brachiopods. |
Car park of the Sun Inn on B4368 about 5 miles from Craven Arms. Parking and
refreshment! |
RIGS Yes. A large and very accessible site which has potential to show the
Ludlow Bone Bed. False bedding and current bediding and slumping visible. |
Sedimentology/Stratigraphy |
|
1199 |
SO 503 858 |
Bache Mill Lane |
Cutting (road/railway) |
Silurian: Upper Ludlow Shales and Downton Castle Sandstone |
|
Exposure comprises a sequence of roadside cuttings and small roadside
quarries on both sides of the narrow lane leading from the B4368 at
Diddlebury to Bache Mill and Middlehope. The section begins with a rather
fragile garden wall in Downton Castle Sandstone which is then succeeded by a
constant horizon in Upper Ludlow Shales as the lane ascends the dip-slope.
These are of calcareous siltstones. The Bone Bed does not appear to be
present or visible. Up to 2 m high over length of 300 to 400 m. SE-facing
dip slope; conformable. |
Lane heading N from Craven Arms/Bridgnorth road at Diddlebury. Parking on
roadside verge just north of lane junction. Traffic hazard in narrow lane
but visibility good |
RIGS Yes. Accessible exposure of Downton Castle Sandstone succeeded by Upper
Ludlow Shales. |
Sedimentology/Stratigraphy |
|
1215 |
SO 586 851 |
Cockshutford Stream - Abdon |
Stream/brook |
Devonian: Clee Group of sandstones. TYPE LOCALITY: Upper Devonian Clee Group |
|
This stream-way ascends the western slopes of Brown Clee and provides a
complete 1 km section through the yellow sandstones marls and occassional
conglomerate of the Clee Group. No fossils recorded in ref(1). Gentle dips
to SE; some large scale current bedding acc. to ref(1). |
Via minor roads on SE side of Corvedale to road-end at Cockshutford
SO580850. Then follow tarmac road through 2 gates and then for ca. 500m;
then head NW down through bracken to approach stream where follow path of
sorts until (past an old chapel on the right (S)) a grass ramp leads down to
stream-way itself at start of section. Ample vehicle parking at road-end;
nearest cafe etc. at Ditton Prior ca. 7 km |
RIGS Yes. This is the type section for the Devonian Clee Group with a
complete section through marls sandstones and conglomerates between Abdon
Limestones and the Coal Measures of Brown Clee. |
Sedimentology/Stratigraphy |
|
1216 |
SO 593 843 |
Clee Burf - Burwarton |
Quarry (disused) |
As mapped; Dolerite is always above Coal Measures. |
|
Sandstones of the Clee Group are succeeded by Coal Measures which in turn
are intruded by dolerite such as occurs at Titterstone. The resultant
outcrops are clearly displayed on the summit plateau of Clee Burf at 1800'
AOD. The area includes many bell-pits and quarried dolerite in all stages of
weathering as well as abundant Coal Measures spoil. General dips are to SE;
dolerite upper surface shows slight chilling. |
Footpaths from all directions to summit of Clee Burf. Ditton Priors:
parking; cafe; Inn. |
RIGS Yes. The hill top area of open pits and quarry designated as a RIGS
since it comprises a unique combination of the highest coal workings in the
UK with ‘bell pits’ sunk through a dolerite capping to coal seams below;
plus features of an igneous intrusion displayed within the quarried area. |
Sedimentology/Stratigraphy |
|
1217 |
SO 596 778 |
Radar Quarry (formerly East Quarry) - Titterstone Clee |
Quarry (disused) |
There is no BGS 1:50 000 Memoir covering this area. Dolerite (probably Upper
Carboniferous) intruded into Carboniferous Coal Measures |
|
The very large quarry (now known as Radar Quarry; previously East Quarry)
and landscaped area immediately below (south of) the radar domes on the
summit of Titterstone Clee exposes many large buttresses of fresh and
weathered dolerite (locally known as ‘Dhu Stone’). Rock falls have occurred
here and the faces should not be approached closely. |
|
RIGS Yes. This quarried industrial landscaped area is one of the most easily
accessible and impressive exposures of the Clee Hills dolerite intrusions
extraction of which so dominates the local landscape community and economy. |
Mineralogy/Petrology |
|
1233 |
SO 738 907 |
Quatford Church - Quatt Malvern |
Quarry (disused) |
Triassic: Lower Mottled Sandstone (ref.2); or Permian: Bridgnorth Sandstone
(ref.1) |
Isolated sandstone cliff in the Severn Valley; next to Quatford Church. |
A 25 m roadside section can be examined from the pavement. Here the major
feature in red sandstone is a single trough bedded unit resting on and
overlain by planar cross bedded units. The trough bedding shows tangential
cross bedding inclined up to 10° and has something of the appearence of a
wash-out channel. However ref.1 interprets this as a N-S section through
west-migrating barchanoid bedforms with large crescentic slip faces moving
under the influence of a long term easterly palaeowind. South of the section
is an irregularly quarried area where outcrops display planar bedforms in
three dimensions of maximum inclination 15° where the sandstone is graded in
parts. Soft patches of sandstone are apparently uncemented. Road section is
25 m long and 4 m high; other sections up to 2 m high. No fauna found.
Palaeoenvironment: Dry sand desert with easterly palaeowind. Between the
church and the road is an L-shaped section in reddish sandstone which gives
an overall view of a planar cross-bedded unit. The cross-bedding can be seen
on different scales from 200 mm down to millimetre scale. Texture is that of
a well-sorted medium sandstone with millet seed grains and little cement or
matrix. This suggests an aeolian origin. There are many insect borings in
the rock (probably solitary wasps) which indicates how soft it is. It is
therefore surprising how this Permian Bridgnorth Sandstone stands up as
vertical cliff faces (pore suction and grain interlocking - locked sands).
Moving towards the road it was noted how the changed angle of dip around the
L-shaped exposure gives a 3-dimensional perspective from which the true
direction and angle of the local dip can be calculated. Along the pavement
towards Bridgnorth is a single trough-bedded unit on both sides of the road.
Orientation is east-west and the curved bedding is seen to wedge out as it
approaches the horizontal base. This unit can be considered as a
cross-section of a small barchan dune moving east-west. |
On A454 3 km south of Bridgnorth in Kidderminster direction. Large layby on
east side of road; eating places 0.5 km further south. |
RIGS Yes. An excellent example of a single trough-bedded sanstone unit
interpreted as a section of a barchanoid dune form perpendicular to its
direction of travel. The upstanding block near the church entrance provides
clear illustration in 3 dimensions of cross-bedded units. |
Sedimentology/Stratigraphy |
|
1236 |
SO 794 940 |
Claverley Road Cutting (N) |
Cutting (road/railway) |
Lower Triassic: Wildmoor Sandstone Formation (`Upper Mottled Sandstone'). |
|
An extensive exposure of bright red Triassic sandstone that shows elaborate
and extensive sedimentary structures. Designated an SSSI; the section shows
a variety of sedimentary structures including flat bedding; planar-;
tubular- and trough- cross-bedding. 150 metres long by 10 metres deep
following the path of the road. The extensive and great variety of
sedimentary structures in this Lower Triassic sandstone indicate that
deposition occurred in a sandy alluvial system with the river flowing
towards the north-west. Some horizons within the sands may have been
deposited as a result of wind action and it is therefore an important site
for the study of Triassic environments. |
Take the A454 Wolverhampton Road out of Bridgnorth. After about a couple of
miles there is a turning on the right hand side of the road situated between
a garage and the Wheel o Worfield Public House. Turn right here signposted
Claverley. Follow this narrow country lane for about two miles until
reaching a `T' junction. On the right the village of Claverley and the
church may be seen - turn left towards Shipley and after some 200 m the road
passes through a deep but narrow cutting which is the exposure. Access is
good. However; this is a deep but narrow cutting on a single track country
lane with no passing places and as such passing traffic may prove a danger
to the visitor. |
RIGS Yes. The site designated a RIGS as an exemplary exposure in aeolian
Triassic Sandstones with a wealth of sedimentary detail. |
Sedimentology/Stratigraphy |
|
1237 |
SO 794 940 |
Claverley Road Cutting (S) |
Cutting (road/railway) |
Lower Triassic: Wildmoor Sandstone Formation (`Upper Mottled Sandstone'). |
|
An extensive exposure of bright red Triassic sandstone that shows elaborate
and extensive sedimentary structures. Designated an SSSI; the section shows
a variety of sedimentary structures including flat bedding; planar-;
tubular- and trough- cross-bedding. 150 metres long by 10 metres deep
following the path of the road. The extensive and great variety of
sedimentary structures in this Lower Triassic sandstone indicate that
deposition occurred in a sandy alluvial system with the river flowing
towards the north-west. Some horizons within the sands may have been
deposited as a result of wind action and it is therefore an important site
for the study of Triassic environments. |
Take the A454 Wolverhampton Road out of Bridgnorth. After about a couple of
miles there is a turning on the right hand side of the road situated between
a garage and the Wheel o Worfield Public House. Turn right here signposted
Claverley. Follow this narrow country lane for about two miles until
reaching a `T' junction. On the right the village of Claverley and the
church may be seen - turn left towards Shipley and after some 200 m the road
passes through a deep but narrow cutting which is the exposure. Access is
good. However; this is a deep but narrow cutting on a single track country
lane with no passing places and as such passing traffic may prove a danger
to the visitor. |
RIGS Yes. The site designated a RIGS as an exemplary exposure in aeolian
Triassic Sandstones with a wealth of sedimentary detail. |
Sedimentology/Stratigraphy |
|
1238 |
SO 386 802 |
Coston Manor - Aston-on-Clun (1) |
Quarry (disused) |
Ordovician: Hoar Edge Grit (ref.1); Ordovician: Coston Beds (ref.2) |
|
On the eastern slope of Clunbury Hill but separated from it by component F1
of the Church Stretton fault is an area of basal Ordovician grits and
sandstones originally mapped and described in detail by Dean (ref. 2). 5
specific localities were subsequently designated as forming a SSSI
notification for the stratotype sections of the Costian Stage. Access to the
area has been curtailed by the owners but special permission for a visit was
secured by Dr. Helen Boynton. Site '1' is the Upper Coston SSSI. The
outcrop is a bank 3 m wide & 1 m high. A basal pinkish grit with small
pebbles and lenses of decalcified shells visible; tend to be flaggy at top
and a massive grit at base. Dip 35° at 290 (WNW). To the right the exposure
is truncated by a fault trending 320° and showing slickensides. Numerous
brachiopods collected here and from an adjacent temporary excavation
[SO387803]. |
Discouraged by owners; a public bridleway passes from top to Clunbury Hill
to Coston Manor but is signed as not giving a through way to Aston or
Beambridge; this does however run alongside the bank exposure at this
locality |
RIGS Yes. The quarries and exposures in the vicinity of Coston Manor are
designated a RIGS as the surviving type sections for the Costian stage of
the Ordovician Period |
Sedimentology/Stratigraphy |
|
1259 |
SJ 3921 2065 |
Ruyton Cliffe (reservoir) |
Quarry (disused) |
Triassic: mostly Keuper Series: Ruyton and Grinshill Sandstones; possibly
Upper Mottled Sandstone below. |
West-facing scarp of Ruyton Cliffe. |
Massive Ruyton Sandstone with many holes produced by weathering. The face is
red-brown in colour; about 4 m high and the rock finely arenaceous and
well-sorted. The basal horizon is approx. 1.5 m thick with prominent
iron-rich concretions. At the top of the exposure; thinner irregular layers
can be seen. The surfaces here are fairly fresh and there is noticeable
orange-red iron staining on the RHS. There was evidence of a fault;
infilled with rubbly rock and spheroidal weathering present. There is a
good view westwards over the drift-covered plain towards the Ordovician
Breidden Hills and the Berwyns. |
From a public footpath. |
RIGS Yes. Designation because there is structural; and weathering interest
as well as good faces of representative Ruyton Sandstone combined with an
instructive view. |
Mineralogy/Petrology |
|
1261 |
SJ 3932 2051 |
Ruyton Cliffe (S) |
Quarry (disused) |
Triassic: Keuper Series: Ruyton Sandstone. Sheet 138; Wem |
Scarp slope of Ruyton Cliffe facing south. |
This is the best of the old quarries on the Cliffe; it is circular with a
rock entrance. One of the massive vertical faces is approx. 12 m high. There
is a gradual colour change upwards from a bright red to beige at the top.
About 4 m from the base is a prominent boundary below which the rock is
massive and red-brown; above it there are clear; large-scale; unidirectional
cross-bedded units. The boundary roughly coincides with the colour change.
The uppermost 1.5 m are thinly bedded and appear to be lying horizontally
above the cross-bedded strata. There are many large joints and possible
faults in the east corner. Continuing to the top of the hill via the
footpath the topmost beds of the quarry can be examined although a vertical
drop makes it necessary to be careful. The sandstone here is light in
colour and is traversed by numerous silica-filled or iron-rich joints which
stand proud from the rock but have no real consistent direction. The
viewpoint from the picnic area at the top is magnificent. |
Via an old track through the rocky entrance which branches off the footpath. |
RIGS Yes. Designation because the sequence through the Ruyton sandstones
displays many features of structural and sedimentary interest. |
Sedimentology/Stratigraphy |
|
1262 |
SJ 3940 2415 |
Ruyton (Blackberry Hill) |
Quarry (disused) |
Triassic: Keuper Series: Ruyton Sandstone. Sheet 138. |
Quarry is cut in the high cliff alongside the R. Perry. |
The rock is the typical Ruyton freestone; a fine-grained; dull red sandstone
with yellow blotches and linear patches of buff. The height of the exposure
is up to 9 m and lateral extent 30 m. Because of the chisel marks it is
difficult to see detail of sedimentary structures although there is evidence
of cross-bedding. The top 2 m show strata which are very broken and
irregular. At the furthest end of the quarry; in the SW corner; is a
prominent joint filled with sand fragments and thin laminae running parallel
to the joint plane. It is possible this is a fault but there seems to be no
conclusive evidence and Pocock refers to it as a joint. The direction of
the joint plane is NE/SW. Adjacent to this feature is a face with smaller
joints crossing each other at angles of approx. 120 and 60 degrees forming a
diamond pattern. A few metres north from this face a small but clear fault
can be examined. The fault plane runs nearly parallel to the face again in a
direction of NE/SW. There are about 6 m of slickensided fault plane exposed
(3 layers of slickensided surfaces being visible). The gap along the fault
is about 6 m and is infilled with some mineralisation but also with
brecciated fragments. The slickensides appear to show near-vertical
movement. |
There is a convenient footpath but the quarry is a few metres off it through
a wire fence by the river. |
RIGS Yes. Designation because the site is a clear example of Ruyton
Sandstone with interesting fault and joint structures. |
Mineralogy/Petrology |
|
1264 |
SJ 4755 2290 |
Webscott T-junction |
Quarry (disused) |
Triassic: Sherwood Sandstone Formation: Wildmoor Sandstone overlain by
Grinshill Sandstone. Wem Sheet 138. New nomenclature from Toghill: 'Geology
in Shropshire.' |
SW facing scarp of sandstone ridge. |
A large quarry; one of several along this ridge; with exposures up to 12 m
high. Faces are vertical and massive with few visible bedding planes. The
sandstone is a dull but sometimes brighter red with a few light blotches
which is crossed by numerous; sub-parallel joints. The joints are generally
infilled with harder; siliceous material and trend approx. 25 degrees off
the vertical. The sandstone is fine and well-sorted. There are noticeable
holes; the product of weathering; and indistinct cross-bedding. At the top
are about 2 m of thin bedded; yellowish; cross-bedded sandstones; belonging
to the Grinshill Group. The NE face is crossed near the top by projecting;
infilled joints. The joints are very interesting and on the left of the
steps are several sub-parallel ones with perhaps slumping; and one very
obvious infilled example which may be a fault. There are extensive exposures
along the road here and the whole stretch from Myddle to Harmer Hill invites
closer examination. |
Public access from the road. |
RIGS Yes. Designation because it is an extensive and good example of
Wildmoor Sandstone (U. Mottled) and its boundary with basal Helsby Sandstone
(Grinshill Sandstone) which displays interesting joint structures. |
Structure and Sedimentology/Stratigraphy |
|
1265 |
SJ 4765 2339 |
Webscott Woodlands |
Quarry (disused) |
Triassic: Sherwood Sandstone Formation: Wildmoor Sandstone (Upper Mottled)
overlain by Helsby Sandstone (Grinshill Sandstone). |
On SW-facing scarp slope of sandstone ridge. |
Rocks here are higher in the sequence than at SJ 476229 and a better
examination of the Grinshill strata is possible. The boundary is unclear on
the south-east side of the footpath but on the north side 2 m of yellow;
cross-bedded Grinshill sandstone can be seen lying on top of the redder
Wildmoor sandstone on a vertical cut quarry face. Also; a large vertical
joint or fault with bright red sandstone infilling a gap of 0.5 m can be
examined close by. Further into the quarry; still on the north side; 5 m of
thinly bedded sandstone; mostly covered by moss and algae; with harder
infilling of small joints forming a criss-cross pattern; seems to be
Wildmoor sandstone; but a few metres on; a natural exposure of about 4 m of
Helsby basement beds; the light-coloured Grinshill sandstones is exposed.
It is possible to find a similar horizon opposite on the south side.
Glacial granite erratics lie by the footpath. |
A public footpath goes through the quarry and from it; looking SE the
current workings for sand can be seen. |
RIGS Yes. Designation because the Wildmoor and Grinshill boundary is clear
and accessible; joint patterns and structures are interesting and some
present quarrying activity can be seen. ( It may be that this whole stretch
of exposures from Myddle to Harmer Hill should be designated one RIGS. The
two largest quarries have been described in this report and in SJ476229) |
Sedimentology/Stratigraphy |
|
1267 |
SJ 5148 2415 |
Clive (church) |
Track/roadside |
Triassic: Sherwood Sandstone Formation: Grinshill Sandstone. Sheet 138 Wem. |
NW end of Grinshill, SE end of Clive. |
Grinshill yellow sandstone is here very thinly bedded and is about 4 m high.
The interest of this site lies in the spheres of barytes densely packed in
the layers of sandstone. They vary in size from less than 10 mm to 50 mm
and are scattered randomly within the rock. Although the condition of the
exposures is not everywhere good there are enough clean surfaces to examine
these small barytes nodules and they are an unusual feature. They can be
seen again in the rock of the steps that lead to the school; standing proud
of the surface in places and also in a red sandstone exposure about 10 m
from the SE corner of the churchyard. Blocks of sandstone containing the
barytes spheres are found in the wall opposite this corner. |
Public road and footpath. |
RIGS Yes. Designation because concentrations of barytes have here formed
spheres in sandstone; an unusual phenomenon and therefore of much geological
interest. |
Mineralogy/Petrology |
|
1272 |
SJ 526 238 |
Grinshill Quarries |
Quarry (disused) |
Triassic: Sherwood Sandstone Group (Grinshill Sandstone Member) and Mercia
Mudstone (Tarporley Siltstone Formation and Bollin Mudstone Formation). New
nomenclature from Thompson: 'Guide to History and Geology of
Quarrying......in Corbet Wood; Grinshill' |
Near the top of SW facing scarp slope of Grinshill. |
At locality 4 on the nature trail; a short path leads to an excellent old
quarry face which reveals a complete succession of the local Triassic.
Buff/white Grinshill Sandstones; about 7 m thick; lie at the base of the
exposure which towers to a height of approx. 18 m. These display a
sub-horizontal erosion plane near the base; and cross-bedded foresets of a
former sand dune 4 m high. There is a distinct break marking the lower beds
of Tarporley Siltstones (flagstones here) which have a thickness of 8-9 m.
The original discoveries of bones and fossil footprints of Rhynchosaurus
came from a comparable horizon to this rock unit within these Bridge
Quarries. Both of the lower rock units are crossed by near vertical joints;
and a fault on the west of the exposure. At the top of the face are about 2
m of Bollin Mudstones. A rough steep path on the west leads to an overhang
of Grinshill Flagstones which here display current and wave ripple marks. On
the east side of the face; another short path leads past an excellent
slickensided fault plane; aligned at 37 degrees and dipping 85° SE. The path
ends at a rock barrier over which another large; very deep quarry can be
seen. (see slides). Continuing along the main path for a few metres; the
west end of Bridge Quarries is reached. The succession is repeated here and
again the boundary between Grinshill Sandstones and Tarporley Flagstones is
easily seen by the change to thinner strata and a recess in the face.
Another recess is seen about two thirds of the way up the face; this may
represent another erosion surface (see slide). |
Easy; public access from the main footpath on the nature trail. |
RIGS Yes. Designation because the original fossil bones and footprints were
discovered here; the face is excellent and accessible; and as well as the
complete succession there are sedimentary structures; joints and faults to
be seen. Suitable for groups of students and is a very good site for
fieldwork. |
Fossils and Sedimentology/Stratigraphy |
|
1274 |
SJ 5262 2380 |
Grinshill Working Quarry |
Quarry (working) |
Triassic: Sherwood Sandstone Formation (Grinshill Sandstone Member) and
Mercia Mudstone Formation (Tarporley Siltstone Formation and Bollin Mudstone
Formation). New nomenclature from David Thompson: 'Guide to History and
Geology of Quarrying' 1995. |
Quarry at top of south-facing scarp of sandstone hill; Grinshill which
stands prominently above the plain. |
Most of the working quarry can be seen from a view-point a short distance
along the path leading NW from Corbet Wood carpark (GR SJ 52602875). The
rocks can be seen exposed in near-horizontal layers; the variation in colour
from cream to red emphasising the changes in lithology (see slide). Strata
actually dip 5° N towards the Cheshire Basin. The lower part of the quarry
is composed of whitish massive Grinshill sandstone ca. 20 m thick. Skeletal
fragments of an early lizard-like reptile; Rhynchosaurus have been found in
this quarry and the possibility of finding more of these is the reason for
its designation as part of an SSSI for vertebrate palaeontology. Above these
sandstones lie the Grinshill Flagstones of the Tarporley Siltstone
Formation. The boundary between these and the massive sandstones below is
clear to see. The whitish flagstones are 7-9 m thick and between the layers
are greenish siltstones; known for their sedimentary structures. Above the
siltstones a few metres of red siltstones and mudstones of the Mercia
Mudstone Group form the unproductive overburden to the quarry. |
The viewpoint is readily accessible from a public path leading from the
Corbet Wood carpark. Permission to enter the quarry may be obtained from
the office on site. Small groups could be accommodated. |
RIGS Yes. Designation because the quarry since Darwin and Huxley's time has
been known for the reptile footprints and there is a possibility of finding
more. There is a good exposure of the Triassic succession described above
and the dyke represents one of very few exposures of rocks in the county
dating from the Tertiary Period. |
Sedimentology/Stratigraphy |
|
1276 |
SJ 3850 1922 |
Nesscliffe Hill |
Quarry (disused) |
Triassic: Sherwood Sandstone Formation: Wilmslow Sandstone; and Helsby
Sandstone (Ruyton Sandstone). Sheet 138 (with old classification) |
Abrupt vertical cliff at southern end of Nesscliffe Hill. |
In this main quarry; the faces are impressive and vertical; the height being
25-30 m. There is a transition from the Wilmslow Sandstone to the Ruyton
Group from bottom to top of the cliff but no sign of a boundary. The beds
at the bottom are deep red and soft. The colour becomes yellower and less
deep red upwards in the sequence. Many joints; some curved; cross the face
diagonally. There are cross-bedded units halfway up the quarry face but no
sign of true bedding. The overall impression is of a high face of massive
sandstone. At the top; the beds are less massive and show curving
structures which may represent channelling. The Ruyton Sandstone ends
abruptly here being cut by the powerful E-W fault; a branch of the main
Axial Fault of Great Ness and Middle. A few metres NW is Kynaston's Cave;
inhabited until at least the 18th century and excavated into another high
cliff in the Ruyton Sandstone. The rocks are weak; red with patches of
yellow and noticeably cross-bedded. Unfortunately; the chisel marks left
after quarrying tend to obscure detail of sedimentary structures. There are
other similar exposures especially at the south end of the hill. |
Via public footpaths |
RIGS Yes. Designation because this is an excellent; accessible example of
the transition between Wilmslow and Ruyton Sandstones. Would recommend
whole of Nesscliffe Hill as RIGS. |
Sedimentology/Stratigraphy |
|
1278 |
SJ 4875 2140 |
Pim Hill |
Natural exposure |
Triassic: Sherwood Sandstone Formation (Bunter): Wildmoor Sandstone (Upper
Mottled) and Helsby Sandstone (Keuper) Grinshill Sandstone. Sheet 138 Wem;
and Toghill 'Geology in Shropshire' |
Near the top of the scarp slope 300m N of Pim Hill. |
The old vein forms a gorge running approx. N-S along a fault. It is from 4-8
m wide and up to 6 m high. The best exposure is at the southern end where
it narrows and is steeper. Grinshill Sandstones; beige in colour with
specks of red; brown and grey and with manganese oxide; are exposed on the
east side. This rock is uniform in texture and is a medium grained
sandstone. On this side of the vein are good examples of slickensides with
polished; mineralised surfaces. The mineral is white but not CaCO3;
possibly being BaSO4. The fault planes trend SW-NE. On the west side of
the vein the rock is redder; finer and softer; being Wildmoor Sandstone.
There is evidence here of a continuation of the SW-NE trending fault but no
mineralisation. The gap; possibly the fault line; varies in thickness;
being up to 0.5 m at the top and filled with loose reddish sand. Longer
investigation; at the head of the vein may reveal the boundary between the
two main sandstone types. |
From the public footpath a well-used path through the woods (but not a right
of way) goes past the site. |
RIGS Yes. Designation because the site exposes Grinshill and Wildmoor
Sandstones on opposite walls of a faulted vein which also displays good
evidence of subsidiary faulting. |
Mineralogy/Petrology |
|
1279 |
SJ 6995 0770 |
Telford Town Park - Randlay Pool (SW) |
Natural exposure |
Upper Carboniferous: Upper Coal Measures: Coalport Formation. |
SE facing slope of sandstone ridge west of Randlay Pool. |
This exposure consists of massive; yellow; brown-weathering sandstone; beds
being over a metre thick. This is part of the 'Thick Rock' of the Coalport
Formation. The overall height of the exposure is up to 5 m and it extends
laterally for about 20 m. The texture is that of a coarse arenaceous rock
with specks of black carbonaceous material. Cross-bedding can be seen
within the beds. About half way up the face the rock is more thinly
stratified; typical thickness being 0.2 m; the appearance being more
flaggy. There is one noticeable infilled joint which forms a chimney-like
structure (see slide 25). There is an example of what appears to be
channelling with fine multi-directional cross-bedding (slide 26) and softer;
recessed area below a massive horizon made up of alternating; very thin;
carbonaceous and sandy laminations (slide 27). The dip of the beds is N/NE
at an angle of 5° or 6°. |
In the middle of a public park with footpath access. |
RIGS Yes. Designation because this is an excellent example of the 'Thick
Sandstone' of this formation with a variety of sedimentary structures.
Public access and substantial size of exposure make it a good site for group
visits. |
Sedimentology/Stratigraphy |
|
1280 |
SJ 7035 0765 and 7025 0760 |
Telford Town Park - Blue Pool (SE) |
Natural exposure |
Upper Carboniferous: Upper Coal Measures: Coalport Formation. |
NE facing slope of plateau-like terrain. |
Approaching from the southern end on the east side of Blue Pool the Coalport
Formation forms a steep slope down to the pool (this is mostly covered with
vegetation but at the foot are large fallen sandstone boulders). Although
moss covers the surfaces; nodules of iron pyrites up to 50 mm diam. can be
seen weathering out of the sandstone. About 200 m further north-east are
cliffs of mainly decaying grey/brown shale which clearly undergo slippage.
Sometimes the shale is very clayey and blue in colour - hence the name of
the pool. A discontinuous layer of hard sandstone blocks occurs 1.5 m from
the top and 4 m below that is another such horizon. To the right of the most
obvious sandstone layer is a distinct 'break' which would suggest a fault;
especially as a small rivulet flows down there and exposes the shale. Iron
nodules can be picked up and the sandstone blocks at the foot of the slope
contain well-formed iron pyrites crystals. There is more massive sandstone
at the NE end of the pool. The dip of strata on this side of Blue Pool is
difficult to ascertain but Sheet 60 gives a 7° dip to the SE. Dips vary
round here probably due to faulting. |
A public footpath goes around Blue Pool so access is easy. |
RIGS Yes. Designation because the site demonstrates typical Coal Measure
shales and sandstones in the middle of a park with unusually good public
access. Reflects economic history of area and is good educationally. |
Mineralogy/Petrology |
|
1296 |
SO 4875 9382 to SO 4905 9320 |
Woodgate Batch |
Bank |
Precambrian: Uriconian: Woodgate Batch Andesites and Dacites |
Over-deepened stream way; relatively straight although not fault-controlled;
in part a gorge feature |
The section runs from a point 600 m SSE of Battle Stones to Greystones
Cottage and comprises ground on both sides of the stream to a max. distance
of 150 m. It thereby includes all the rocky outcrops crags and cliffs which
line the side of the gorge sections. It is assumed in the absence of
specific comment in the memoir (Greig et al. 1968) that the rocks are mainly
sub-aerial lava flows although some occasional tuffs bands are mentioned.
Some 10 individual outcrops were examined and these seem to cover the
principal characteristics. These are: (1) SO4905 9315; a 4 m high X 2 m
square outcrop of andesite with some phenocrysts and showing slight
brecciation; most notable are strong smooth perpendicular joint planes
suggestive of columnar jointing. (2) around SO489935 3 hillside crags up to
4 m high variously brecciated.. (3) SO4885 9358 a hill top at 303 m AOD. A
very weathered outcrop showed distinct flow banding. (4) SO4880 9360; the
top of a complex broken ridge which plunges steeply down to the stream below
trending 260°. To the right the lowest crags are strongly jointed and form a
step topography due to apparent bedding; to the left the lowest point is
marked by a 8 m high face; very weathered with a distinct lamination and
patches of brecciation. These latter two may represent tuffs. (5) On the
west side of the stream between SO486937 and SO487934 are several rocky
bluffs with scree below two of them; a scree slope at SO4874 9345 yielded
rocks of various types; viz. fine grained; porphorytic dark purple slightly
flow banded; deep pink sharp edged and slightly vesicular and a pale coarse
grained tuff. (6) The quarry at SO4877 9340 receives a description in the
memoir; p.23. It has recently been worked for hard-core. Semicircular in
section it has two distinct levels. The upper level (half-circle diameter 15
m) is now 3/4 grass covered due to rapid decomposition of the andesitic
rock. The ‘spheroids’ described in the memoir are scarcely recognisable in
the visible rock at the top left. Only notable feature are two totally
rotted areas of pale gray and yellow colour. The lower ground level;
diameter 24 m; shows massive rock on the left hand side; a porphyritic
andesite variously grey; green or pink. It breaks along the joint planes to
produce irregular flat sided pieces which can have razor sharp edges! To the
right the rock is softer and more resembles that in the upper level. A
distinct 3 m wide fault zone is visible with totally rotted fault breccia.
(7) An impressive vertical cliff lying below SO4900 9380 is dangerous if
approached from the footpath above and has no public access from below.
ACCESS: The most direct access; which leads to (5) & (6) above; is by a
bridleway starting at SO486928 just west of Woodgate Cottage on the Church
Stretton to Much Wenlock road 1 mile east of Hope Bowdler. 600 m further
east a more convoluted footpath starts at Woodgate Farm; passes Gray Stones
and gives access to points (1) to (4) above. |
The most direct access which leads to (5) & (6) above is by a bridleway
starting at SO486928 just west of Woodgate Cottage on the Church Stretton to
Much Wenlock road 1 mile east of Hope Bowdler. 600 m further east a more
convoluted footpath starts at Woodgate Farm passes Gray Stones and gives
access to points (1) to (4) above. |
RIGS Yes. These andesites and dacites cover a large area and this
designation reflects their best exposure. A wide range of exposure type even
if the rock type is ‘difficult’. A de facto type section with some
geomorphology. A neglected area which gives an experience of exploration. |
Mineralogy/Petrology |
|
1297 |
SO 3863 8658 |
Plowden Woods scarp - Lydbury North |
Track/roadside |
Silurian: Wenlock Shales; equivalent to the Silurian: Aston Mudstone |
Crest of apparent scarp |
This section in Wenlock Shales shows development at the top of the scarp in
Plowden Woods. The hard grey mudstone/siltstone exposed in the quarry at the
foot of the slope (SO383867) continues almost to the top of the scarp slope.
This exposure shows the top few metres becoming much more calcareous and
containing an allogenic shelly fauna. At the base of the section bedding is
massive (partly due to bioturbation); in the upper parts this bedding
becomes flaggy due to unloading. However an increasing calcareous content
is evident and some parts have decalcified to a deep brown or brilliant
red-ochre coloured rottenstone. Associated with such decalcification is a
prolific (occasionally dense) fauna which becomes much more distinguishable
from the bioturbated background. This fauna is dominated by small
brachiopods including some strongly ribbed varieties with Dicolesia biloba
particularly prolific; occasional Beyrichian ostracodes (possibly Beyrichia
salopiensis as figured in ref.1) and in an adjacent exposure trilobite
fragments (probably of Dalmanites sp.). This fauna is clearly allogenic and
accumulates as small lenses or coquinas dispersed in the moderately
bioturbated sediment. Further the lithology and fauna have strong
resemblance to beds of the Elton Formation as exposed in the Goggin Road
sections of Mortimer Forest. In view of the situation of this exposure on
the junction between the shelf sediments of the Church Stretton sheet 166
and the off-shelf sediments of the Montgomery sheet 165 it is concluded that
this exposure is better classified as one of the Aston Mudstone Formation of
sheet 165 rather than Wenlock Shale of 166. In view of subsequent
developments in adjacent Edgton beds of the Oakley Mynd Formation and Bailey
Hill Formation this is a crucial exposure in delimiting the boundary at a
specific point in geological time between shelf and off-shelf sedimentation.
Palaeoenvironment: Shallowing water; possibly tidal or storm affected but
too silty for actual limestone to form. |
Section lies some 40 m from the footpath followed by the Shropshire Way and
no explicit notice or barrier intervenes. Via the footpaths used by the
Shropshire Way either from Plowden or Edgton one arrives at a path junction
on the crest of an obvious scarp. From this junction follow the path to the
east for 40 m where the section will be seen in a branch track which begins
to descend the scarp. |
RIGS Yes. Designated a RIGS as a crucial exposure marking the boundary
between shelf and off-shelf sediments at the time of the Silurian
Wenlock/Ludlow series transition. |
Fossils and Sedimentology/Stratigraphy |
|
1301 |
SO 2782 9763 to SO 2794 9814 |
Hagley Upper Ridge - Chirbury |
Mine/adit |
Ordovician: Caradoc Series: Hagley Volcanic Formation |
A whaleback ridge with offsets due to faulting and a good viewpoint |
With alternating hard and soft beds and strata dipping 45° to the west; a
ridge and hollow topography is common in the western margins of the Shelve
Inlier. However; this particular ridge of resistant volcanic tuffs
surrounded on both sides by readily weathering shales is a gem showing a
text book example of a whale-back hill. It has the additional features of
the type section for the Hagley Volcanics; some easily recognised faulting;
and evidence of old mine workings. The roadside quarry SO27829763 is the
type section for the Hagley Volcanic Member (Whittard & Dean; 1979). The
open part nearest the road shows what appears to be a massive pale fine
sandstone; slightly micaceous; however; slabbing confirms that it is devoid
of quartz grains; quite soft and consistent with a very fine grained tuff.
Notable is a distinct mottling usually taken as diagnostic of bioturbation.
Coincidentally the polished surface cut a longitudinal section of the
polyzoa Prasopora grayae (BPF; p.53). To the left a public footpath follows
the western margin of the ridge. There are numerous slab exposures on the
right and confirmation of the volcanic nature of the rock with; for example;
lithic tuffs of clasts of size up to 10 mm. After 300 m there is an
embayment to the right where an adit (SO27859789) indicates old mine
workings for barytes. A second path branches to the right and ascends to the
crest of the ridge passing further workings and an old level showing fault
gouge and vein quartz. This fault is represented on the ridge by a hollow
with the highest point to the right at SO27959785. Hereabouts numerous
small quarries confirm the variability of the volcanics with examples
varying from the mottled type of the roadside quarry to centimetre scale
lithic tuffs. The ridge crest offers a superb viewing platform both of the
local ridge and hollow topography and wider from Corndon Hill; the Kerry
Ridgeway Silurian scarp and towards Newtown and Wales. Continuing north the
ridge suffers a number of offsets which clearly relate to the mapped fault
pattern and then a return can be made via the original footpath. |
Hagley is some 2 km south-east of Chirbury and is reached by the road to
Priestweston some 1.5 km from the Whittery Bridge. The roadside quarry in
trees is adjacent to a small pumping station surrounded by a wire netting
fence. |
RIGS Yes. A text book geomorphological feature allied with comprehensible
volcanics and evidence of old mine workings; part of Shelve Inlier ore field
- barytes zone. A wide range of feature; viz. whaleback hill; varying
volcanics tuffs; old mine workings; faults; local topography and viewpoint.
Type section and question whether fine tuffs are bioturbated |
Geomorphology/Landscape |
|
1302 |
SO 471 932 to SO 490 945 |
Hope Bowdler Hill |
Crag |
Precambrian: Uriconian Volcanics |
Differential erosion of hard volcanic rocks compared with surrounding softer
sediments; character of flanks of hill determined by nature of enclosing
faults. |
Of the six ‘Church Stretton Volcanic Hills’ identified and described by the
Geological Survey (Greig et al. 1968) that of Hope Bowdler is the only one
completely defined by faults; these being the normal Cwms-Hoar Edge F3 fault
of Lapworth & Cobbold together with thrust (reverse) faults named as
Sharpstones and Willstone. These enclose an elongated area with a long axis
of 2.5 km aligned SW to NE from the Gaer Stone (SO4723 9340) to Battle
Stones (SO4855 9430) and up to 0.5 km wide. The character of the hill flanks
clearly reflects the nature of the defining faults. The NW flank is
generally straight and of a uniform slope 1 in 2 (ca. 25°) at the foot of
which a hedge line marks the change to the lower angle and softer sediments
of the Cwms inlier. In contrast the SE flank is more undulatory with its
slopes marked by various steep outcrops overlooking the line of change to
gentle slopes which marks the mapped position of the Willstone thrust.
Between these faults is a single rounded grassy ridge with four distinct
‘tops’ at 390 425 426 and 403 metres together with intervening cols; all
being linked by a footpath which is very popular with hill walkers. The
stratigraphy is according to Greig (1968) a simple downward simple sequence
of Andesites Conglomerate Rhyolites (with andesites and tuff bands) together
with two areas of intrusive dolerite. Outcrops of the more basic rocks carry
a heavy patina of staining and lichen with variable degrees of alteration.
The rhyolites and conglomerate are somewhat fresher but overall it requires
some familiarity before rock type can be confidently identified in the
field. Fortunately all significant exposures are easily accessible from the
ridge footpath and these more or less confirm the disposition according to
the 1:25 000 Geological map; Sheet SO49; and Figure 4 (facing page 18) of
the memoir (see however the attachment). As a ‘geological site’ the Hope
Bowdler Hill has the following qualities germane to a designation: (1) as a
geomorphological entity it provides a convincing example of the role of
fault type in the sculpture of a landscape feature; (2) rock exposures are
sufficiently distinctive to allow for field recognition of local faulting;
(3) there is an intriguing contact between the conglomerate and dolerite
intrusion at SO4734 9345; (4) there is a particularly fine section showing
rhyolite xenoliths in a dolerite matrix (SO4740 9345 to SO4344 9350); (5)
rock outcrops along the SE flank raise the question as to how far if at all
they have been affected by the adjacent thrust; (6) actual outcrops of the
conglomerate bed provide evidence to support the interpretation by Pauley
(1991) that this is a representative of the Longmyndian and overlies both
rhyolite and andesites unconformably; (7) it provides exemplary viewpoints
both of the cuesta landscape to the SE and across the Cwms sedimentary
inlier to Caer Caradoc; (8) there is a sequence of exposures along the
ridge from Gaer Stone to Battle Stones well able to support a geological
trail or itinerary with potential to extend NE to Sharpstones and Hillend or
SW to Ragleth Hill. (NOTE: An outline of such an itinerary is attached to
this report as a vehicle for presenting fuller data of this survey) |
A footpath apparently established by common usage runs from Gaer Stone to
Battle Stones. The former can be reached by public footpath from Sandford
Seat (SO468933) 1.5 km from Church Stretton on the Much Wenlock road; the
latter by public footpath from Willstone Upper Farm (SO492953). A public
bridleway from Hope Bowdler village crosses the ridge at a col (SO482942)
400 m WSW of Battle Stones. |
RIGS Yes. Designated a RIGS as a compact and accessible Precambrian volcanic
sequence showing features attributable to faulting intrusion and
unconformity plus xenoliths; also offers comparison with other sequences
such as that of Caer Caradoc. Feature mapping; rock types associated with
Island Arcs and geomorphology. offers scope for discussion of a revised or
new interpretation of the stratigraphy. Exemplary viewpoint pertaining to
local geology. |
Mineralogy/Petrology |
|
1303 |
SO 4418 9238 to SO 4425 9170 (?) |
Rudges - Little Stretton |
Quarry (disused) |
Precambrian: Longmyndian: Stretton Shales. Silurian: Llandovery: basal
Pentamerus Beds |
Top edge of very steep 40 m high bank dropping down to stream |
Interesting exposures in Stretton Shales which reveal the overlying basal
Silurian grits. The several exposures are described here as linked in a
roughly 400 m long section. The section begins at the gate (marked G1 on the
attached map) at SO4418 9238 from where the path runs south along the top
edge of the Ashes Hollow stream bank. In 50 m are exposures of shales
(locality 1) with an anomalous dip to the NE of 65°. At (2) (SO4417 9229) is
a small quarry with a strong joint face trending 220° in Stretton Shales.
The north side shows these shales with low dip curving over to near
vertical; the south side is of dolerite which contacts the shales near the
joint face. Locality 3 is an exposure of shales striking at 220° but
affected by the distortion of kink banding. Locality 4 (SO4417 9211) is a
second quarry 16 m wide and 3 m high in the eastern bank of the path. Here
the shales dip more normally to the west but with very variable dips; 30° to
80°; and very much affected by flexure and incipient kink banding. On the
west side of the path is dolerite exposed as a narrow rib 18 m long opposite
the quarry. Beyond the quarry is a gate which gives access to a sunken lane.
Locality 5 (SO4416 9208) is just beyond this gate and comprises a number of
small exposures of highly brecciated shales which would seem to correspond
to a fault breccia (although no such fault is shown on the BGS 1:25 000
map). From locality 5 rough tracks lead just south of east in 150 m to a
gate G2 on a surfaced farm track; 50 m south along this track locality 6
(SO4425 9197) presents exposures of the Silurian. These are of several
square metres of admixed pebbly conglomerate; purple grits and finer
sandstones on both sides of the track with a dip to the south-east of 25°.
These are clearly banked against underlying; but unexposed; Stretton Shales
forming a beach deposit. No fossil casts were found apart from tenuous
indications of columnals. The exposure ends as the track turns right leading
out to the tarmac road in Little Stretton. |
via path described above |
RIGS Yes. Designated a RIGS as the most northerly example of the basal
Silurian unconformity in conjunction with exposures of underlying shales
showing distortions associated with faulting and dolerite intrusions. The
re-opening in August 2001 of a permissive (?) path between Crossbanks Ludlow
road Church Stretton and Little Stretton (SO445930 to SO441920) has given
access to these exposures which are significant for understanding the
phenomenon of kink banding. |
Structure and Sedimentology/Stratigraphy |
|
1306 |
SO 3102 9816 to SO 3135 9917 |
Stapeley Hill (SE) - Worthen with Shelve |
Quarry (disused) |
Ordovician: Llanvirn Series: Hope Group; Stapeley Volcanic Formation (BGS;
1991); Shelve Formation; Stapeley Volcanic Member (Whittard & Dean 1979) |
Landscape of ridge centred on steeply dipping volcanic rocks and valley
hollowed in softer shales both leading to plateau area of dolerite |
The single unit of three volcanic horizons of Whittard - the Stapeley
Volcanic Member (bounded to the west by shales) the Stapeley Shale Member
and (to the east) the overlying Hope Shales (Whittard & Dean; 1979; p.29) -
was re-mapped by BGS as a complex of volcanic tuffs and lavas - the Stapeley
Volcanic Formation - lying within the Hope Shales. Figure 1 shows the
resultant BGS stratigraphic column and figure 2 (annotated with locality
numbers) shows the area covered by this report. Figure 3 is the OS map of
the topography and outlines the surveyed area proposed as a RIGS. (1) This
disused quarry centred on SO3102 9816 presents a 30 m wide and 6 m high face
of massive bedded tuffs with strong jointing and areas of spherical
weathering. Low down in the centre of the face a fresh cored area shows a
grey coarse lithic tuff; elsewhere are finer tuffs and high up on the left
is a small intrusion of chilled very fine grained dolerite(?). (2) The point
SO3094 9816 marks the SW end of an emergent outcrop of volcanic tuffs which
forms a continuous rib running along the NE strike for 200 m and dipping NW
55° to 65°. This is here considered to be a significant geomorphological
feature since it demonstrates one of the forms which can result from the
erosion of dipping rocks and bears immediate comparison with Hagley Upper
Ridge and Cwm Dingle. (3) A tor-like feature at SO3100 9825 shows what would
appear to be volcanic ‘bombs’ but in fact are larger partially rounded
clasts of rhyolitic(?) rock. (4) The NE end of the continuous rib is at
SO3104 9833 but scattered outcrops continue ahead for some distance. (5) Off
to the left (NW) the ground falls away into a parallel running smooth sided
valley. Across on the opposite side can be seen a shale exposure (see report
for Upper Stapeley Farm (E)) but hidden from view on this nearer side is a
badger set where excavation has yielded abundant dark grey fissile shale
fragments representing interbedding of the Hope Shales. (6) Continuing along
the main ridge the ground becomes flatter and outcrops less frequent. At a
crossbank a cairn can be seen ahead apparently offset from the trend of the
ridge. This cairn at SO3124 9896 marks the near edge of a large area of
dolerite which has totally blanketed the previous landscape of ridge and
hollow forming instead a roughly level plateau. (7) This second cairn at
SO3135 9917 marks the NE limit of this survey. (8) Return to the quarry of
location 1 can be usefully made along the upper parts of the SW slopes where
further outcrops of the Stapeley Volcanics occur. It is evidence of the
stratigraphic complexity that what was considered by Whittard to be a single
unit of three volcanic horizons - the Stapeley Volcanic Member (bounded to
the west by shales - the Stapeley Shale Member) and to the east by the
overlying Hope Shales (Whittard & Dean; 1979; p.29) was re-mapped by BGS as
a complex of volcanic tuffs and lavas - the Stapeley Volcanic Formation -
lying within the Hope Shales. |
The area of Stapeley Hill covered by this report is unenclosed common land
crossed by numerous paths and a bridleway linking it to the Mitchell’s Fold
Stone Circle. Convenient parking places are therefore either the visitor’s
car-park for the Stone Circle or by the chapel at the start of the hamlet of
White Grit on the Priestweston road. From the latter is 400 m by paths which
will lead to the quarry of locality 1. |
RIGS Yes. A very comprehensive introduction to volcanics and intrusives and
the development of landscape features from underlying rocks. Necessarily the
type section for the Stapeley Volcanic Member. A very evident connection
between the geology and ancient peoples selection of sites for stone
monuments. A coherent combination of rock type and landscape. 360 degree
viewpoint embracing Long Mountain; Corndon Hill; Stiperstones and Pontesford
Hill - all geologically based! |
Mineralogy/Petrology |
|
1309 |
SO 446 916 to SO 458 927 |
Ragleth Hill - Church Stretton |
Natural exposure |
Precambrian: Uriconian: Ragleth Tuffs |
Relatively erosion-resistant volcanigenic basement rocks revealed by
faulting. |
If considered as the outcrop area of the Ragleth Tuffs then Ragleth Hill
forms an elongate ridge running SW to NE for some 1.65 km; reaching an
altitude of 398 m AOD (1305 feet). The maximum width of the outcrop of tuffs
is approx. 500 m and covers an area of approx. 0.75 sq. km. Geological
boundaries are the Ordovician Harnage Shales to the SE mapped as faulted by
BGS and the basal Longmyndian Helmeth Grits to the NW mapped as an
unconformity by BGS (Greig et al.; 1968) although considered to be
‘stratigraphically insignificant’ by Cobbold & Whittard (1935) and even
conformable by Pauley (1991). It can be noted that both boundaries follow a
change of slope; for the Ordovician this is a sharp lessening of angle from
hillside to cultivated field but for the Helmeth Grit there is a pronounced
increase in slope angle on entering Ragleth Wood particularly at the
southern end. The hill could be taken as providing the type section for the
Ragleth Tuffs but there is a general sparsity of exposure and better more
definite sections of the tuffs are to be found along the SW ridge of Caer
Caradoc. In fact the major outcrops amount to only four in number with
positions as marked on the attached map and there labeled A to D. (A) On
the northern slopes of the hill this is discontinuous sequence of exposures
all lying along a south trending strike for 120 m from SO4584 9259 to
SO4582 9248. Outcrop is of a roughly bedded tuff similar to that of
3-Fingers Rock on Caradoc. Bedding is particularly obvious at the lattermost
NGR where the outcrop is of a 4 to 5 m high face dipping ESE at 75°.
Polished surface (slabbing) shows a fine pale and dark banding and confirms
that the visible texture is one of true bedding. (B) There is a
complementary outcrop on the southern slopes which forms a prominent
step-like feature clearly visible from the A49. Up to 3 m high this step
extends for 100 m from SO4504 9163 to SO4494 9159 with a discernible N-S
strike cutting across the feature with dips variable either side of the
vertical. There is some evidence that this feature is truncated by faulting
at its NE end. (C) The south west end of the hill offers an area of
scattered outcrops which appear to have been subject to quarrying or
excavation in the distant past. Among these at SO4490 9170 is an in situ
exposure of conspicuous near brick red rhyolitic tuff (?) at the end of a
feature which appears to dip 60° NW. This has significance as it is
conformable with some dips in the Helmeth Grit and with the regional dip of
the Longmyndian. (D) This small crag of coarse massively bedded tuff seems
connected to A with an apparent dip of 80° SE. The rock itself deserves
comment: polished surfaces show a granitic composition with equi-sized
grains of angular pink felspar; angular and rounded grains of transparent
quartz and irregular grains of biotite mica. That it is not a granite is
show by: a) freely fractured surfaces show the quartz as perfectly formed
clear pinacoid crystals; b) there are occasional fragments of alien rock;
typically a purple shale. Thus the rock is to be classed as a
‘crystal-lithic tuff’ which has undergone free growth and/or
recrystallisation of the quartz (silification). (E) Around the summit pole
at SO4509 9176 are several rhyolitic blocks some or all of which are not in
situ. A few metres to the NW a genuine in situ exposure appears to show a
dip to the NW. In spite of sparsity of outcrops; Ragleth Hill offers some
scope for an itinerary; especially if combined with exposures of Helmeth
Grit in Ragleth Wood (q.v.). A possible route is shown on the attached
sketch map and starts from the top of Poplar Drive (off Chelmick Avenue) at
SO4585 9300. It deliberately avoids the barren footpath along the ridge
taking instead a lower path on the SE flank which provides an improved view
both of the change on slope at the Ordovician boundary (not visible from the
ridge path) and the development of scarp features in the succeeding
Ordovician and Silurian sediments. There are a number of further outcrops
around this traverse which supplement those of A; B & C. |
Open access to the whole area via public footpaths |
RIGS Yes. A major locality in determining the exact nature of the
Precambrian transition from a predominantly volcanic to a sedimentary
environment (especially when taken in conjunction with the Helmeth Grit of
Ragleth Wood). Good exercise in recognition of bedding and appreciation of
mapping problems and techniques. Significant in the context of Uriconian to
Longmyndian (volcanic to sedimentary) transitions. Widespread views from
itinerary traverse and even more so from summit footpath. |
Mineralogy/Petrology |
|
1310 |
SO 446 916 to SO 458 927 |
Ragleth Wood - Church Stretton |
Natural exposure |
Precambrian: Longmyndian: Stretton Shale Series: Helmeth Grit Member |
Scree and rock outcrops with at least one small patch of fluvio-glacial
debris |
The linear outcrop of Helmeth Grit lies between the slopes of the NE flank
of Ragleth Hill where it has a length of 1.75 km between SO446916 and
SO458927 and maximum (horizontal) width of 100 metres. Its geological
boundaries are apparently conformable to the overlying Stretton Shales but
debatable to the underlying Uriconian Volcanic Ragleth Tuffs. The outcrop is
wholly covered by woodland - Ragleth Wood - whose edges roughly correspond
to the geological boundaries. However these are more accurately placed by
changes of slope there being a general steepening of gradient in passing
from the Ragleth Tuffs and a lessening in passage to the Stretton Shale
lithology. In the southern part there is extensive scree clearly felt as
lying just beneath the very thin soil surface. Whilst the Helmeth Grit was
recognised as having a distinctive lithology by the Geological Survey (Greig
et al.; 1968) surprisingly no specific description of what this lithology is
was given; the memoir choosing to rely entirely on the descriptions given
earlier by Cobbold & Whittard (1935). From a now obscured section in Hazler
Road; Church Stretton; a natural outcrop in Ragleth Wood and an excavation
in ‘the triangular field abutting against the SW end of Ragleth Wood’ these
authors described the Helmeth Grits as an interbedded sequence of four ‘Grit
bands with somewhat variable shales to a total thickness of 98 feet (30 m).
From petrographic work they concluded that ‘the rocks are .. lithic tuffs
formed .. from already consolidated Uriconian types .. and may be taken to
represent the decadent phases of the vulcanicity of the Uriconian’. The
absence from the memoir (Greig et al.; 1968) and from the paper of Pauley
(1991) of any mention of specific outcrops of the Helmeth Grit suggested
that no worthwhile outcrops remain. Nevertheless; difficult but persistent
exploration of Ragleth Wood has revealed at least four outcrops of a nature
to allow for construction of a large part of the sequence. Rock samples
recovered from these outcrops tend to confirm the findings of Cobbold &
Whittard but show; if anything; an even wider variety of volcanigenic type.
The position of four outcrops are indicated by letters A to D on the
attached map and each is given an identifying name in the follow
descriptions: (A) Original Quarry at SO4494 9224; closest to the overlying
Stretton Shales this shows a massively bedded arkose like sandstone which
has undergone deep weathering of its mafic (?) minerals so that it now
presents a quite porous texture. Unweathered examples of apparently the same
rock type have been recovered from other exposures (including Ragleth Hill
itself) and show an essentially granitic composition of quartz; feldspar and
mafics. Weathered pieces are common throughout the whole outcrop (even on
Helmeth Hill) and show a pale brown/yellow gritty texture that seems to
represent the so-called ‘distinctive lithology’ of Greig et al (1968). Note
that it was this quarry which was the subject of a RIGS designation in 1997.
(B) Charcoal Ridge SO4489 9221; so-named as lying below a charcoal burner's
platform at SO4496 9218 (confirmed by presence of charcoal fragments in the
sub-soil). This is a steep narrow (5 m) outcrop some 25 m long; forming a
ridge of rock which is strongly jointed. There are also further exposures on
the left-hand (NE) flank. Overall the impression is of a lithology similar
to the Original Quarry but sampling (followed by slabbing) shows a wide
range of rock type including lithic tuffs with an arkose matrix; pale grey
brecciated rhyolite; dark gray basalt like (lavas?); dark grey brecciated
shales; mixed crystal (felspar and mafic) and dark grey lithic tuffs etc.
Whilst a sedimentary log would appear feasible it seems likely that the
outcrop is much broken by faulting and hence presents a juxtaposition of
various rock types. (C) Yew Tree Crag SO4489 9206 (top) to SO4486 9206
(base). Whilst the ground hereabouts is cut by deep gullies with seperating
steep ridges this 30 m square outcrop; overshadowed as it is by a large
conspicuous yew tree; is of great importance since it is the only location
where dip direction and magnitude can be unequivocally measured. This is
because the outcrop is of a large bedding plane of ‘grit’ overlain in its
lower part by a thick bed of apparently black ‘shale’. On slabbing the
latter is seen to be finely banded in shades of gray between pale and near
black. There are also interbedded thin 5 mm thick layers of arkose sandstone
which probably represent the ‘sandy shales’ of Cobbold & Whittard (1935).
The latter plus the grit bedding planes confirm a dip to the NW (65° to 310)
conformable with the regional dip of the Longmyndian from Stretton Shales
upward. (D) South-west Gully SO44829184. This is the locality of Cobbold's
excavation in the ‘triangular field’. The gulley marks a SW boundary for the
wood and was the line of the old walker's route up Ragleth Hill starting
from the A49 opposite the lane from Little Stretton. It is steep boulder
filled and awkward. At the top the angle eases and there are outcrops on the
right but a larger main outcrop just in the woodland on the right. There is
no obvious sign of what or where Cobbold's excavation may have been. Both
outcrops provide rock types similar to what has already been mentioned but
without giving clear indications of dip and strike directions. Here would
appear to be the nearest exposures to the underlying Ragleth Tuffs - indeed
Cobbold stated; by a curious piece of circular reasoning; that his
excavation revealed the actual junction. This cannot be claimed now. Between
SW Gulley and Yew Tree Crag the ground is much covered by scree deriving
from a number of small outcrops that have not (yet) been investigated.
Ragleth Wood provides a relevant continuation of an itinerary which begins
by examining Ragleth Hill (q.v.). The route shown on sketch map would
reverse the sequence from SW Gully to the original quarry and then follow a
path around the lower edge of the wood to complete a circuit back to a
starting point in Poplar Drive. This lower path crosses at least one on the
traverse faults which overall affect the outcrop. |
Ragleth Wood seems open both from the slopes of Ragleth Hill particularly by
one or two very visible footpaths or from a path which follows the lowermost
boundary of the wood from vicinity of Snatchfields at least to locality A. |
RIGS Yes. Provides good in situ exposures of the Helmeth Grit which support
claims of vulcanicity continuing (although perhaps waning) into the
Longmyndian sedimentary regime. Good exercise in identification of
volcanigenic rock examples. Critical exposures in any consideration of the
Uriconian to Longmyndian transition. |
Mineralogy/Petrology |
|
1311 |
SO 2950 9785 to SO 2966 9805 |
Cwm Dingle (ridge) - Priestweston |
Natural exposure |
Ordovician: Llanvirn Series: Weston Flags Formation: Upper Sandstone Member.
Upper Grit horizon within Weston Member of Middleton Formation (Whittard &
Dean; 1979) |
Although resembling an escarpment; the high angle of dip (c. 60°) suggests
the notation ‘reversed scarp’ (see attached diagram & note) |
The ridge is the outcrop of the upper ‘Sandstone’ within the Weston Beds and
forms the NW side of the hollow of Cwm Dingle (the lower sandstone; 100 m to
the SE; forms the opposite side). The visible rock outcrop extends for 300 m
forming an ascending ‘edge’ running from SW to NE along the regional strike
direction. Dip is to the NW at about 60°. A path climbs the edge from the SW
and shows strong joint planes; orthogonal to the bedding; overlooking the
dingle to the right forming a pronounced step or ‘scarp’. To the left the
surface is relatively horizontal so that bedding planes are not exposed
except in the numerous small quarried areas which have been worked on this
side. It is this seeming reversal of the role of bedding and joints which
prompts the appellation ‘reversed scarp’ for this topographic feature. BGS
(1991) describes the Weston Flags Formation as bioturbated sandstones and
siltstones. Whittard considers the Weston Member as being ill-sorted shallow
water deposits; possibly estuarine; varying from rough bedded argillaceous
strata to (smoothly bedded) massive units (Whittard & Dean;1979; pp38-39).
Along the ridge where the bedding can be seen it shows an interbedding of
thin rough flags and thicker smoother massive beds. There is an abundance of
talus derived from shallow quarry workings to the left of the edge whereby
both types may be examined. The general grade is coarse siltstone to fine
sandstone. Some beds occur typically as 10 mm thick flags showing fine
laminations and with surfaces much roughened by two agencies. One is the
effect of bioturbation which in some pieces can be seen to have left
vertical burrows filled with light sediment which erupt onto and roughen the
surface and also locally destroy the lamination. Occasional bedding planes
can be found criss-crossed by the casts of ‘worm tubes’; termed fucoid
markings by Whittard. The second effect is that of sole markings which also
seem more organic than physical in origin. The massive beds occur as smooth
surfaced flags typically 30 to 50 mm thick. These can vary from relatively
soft olive and brown siltstone showing planar laminations to hard; near
black and rough fracturing units. Some original calcareous content is
suspected with much decalcification present. A useful adjunct of this site
is that; by choice of access route; it may be better placed in the context
of adjacent sediments of the Weston Formation. Specific localities which can
examined by a recommended route are listed in an attachment. |
A network of footpaths surround Cwm Dingle. Most direct access is by path
heading NE from Priestweston. A more convoluted route starts from a layby at
SO298977 near the summit of the White Grit road. This uses an old road to
Priestweston (now a green lane) and encompasses some half dozen or so
related localities. Details are in the attachment. |
RIGS Yes. A wealth of sedimentary and bioturbation features combined with a
notable topographic feature demonstrably related to the underlying strata.
An excellent location for examination of bioturbation and waning current
sedimentary features combined with an impressive and intriguing
geomorphological feature. Has relevance to the deposition conditions of the
Weston Flags Formation. Some local use of the flags for building stones. |
Sedimentology/Stratigraphy |
|
1313 |
SJ 754 034 |
Grindle Forge - Ryton |
Cliff |
Permo-Triassic: Sherwood Sandstone Formation: Kidderminster Conglomerate and
Bridgnorth Sandstone (Toghill). Sheet 153 has old nomenclature. |
Part of steep escarpment along Wesley Brook. |
An excellent exposure of the transition between Bridgnorth Sandstone and
Kidderminster Conglomerate. 80 m of rock are exposed parallel to the Wesley
Brook reaching a height of 8 m. There seems to be an overall easterly dip
but the whole face shows impressive cross-stratification; both small and
large scale with overlapping units. A recess causes overhang at the base
which on closer inspection coincides with 200 mm of red marl with sandstone
below. Mottling is random but mostly seen half-way up the face. About 8 m
to the east swirling structures can be seen and two thin 30 mm horizons of
finely laminated shaly marl; horizontally bedded some of which is
grey-green. A great deal of small sedimentary detail can be seen including
alternating sandstone/marl layers 2 mm thick. Approx. 30 m from the bridge
another major face shows a small fault which faults out the marl and where
displacement is discernible. Another interesting sedimentary feature is the
slumping of sandstone blocks into the underlying marl resulting in an
irregular sandstone base. It is difficult to identify a boundary between
Bridgnorth Sandstone and the overlying Pebble Beds but scattered small
pebbles make an appearance about two-thirds up the face. |
Open access by the road and beside the brook. |
RIGS Yes. Designation because the sedimentary detail displayed here at the
junction between Bridgnorth Sandstone and Kidderminster Conglomerate offers
much opportunity for interpretation and reconstruction of palaeo-environments
during the Permo-Trias. Also it is an excellent site for groups for
teaching. |
Sedimentology/Stratigraphy |
|
1314 |
SJ 765 015 |
Old Rectory - Beckbury |
Track/roadside |
Triassic: Sherwood Sandstone Formation: Helsby Sandstone (new nomenclature;
Toghill). Old nomenclature on Sheet 153. |
The road cutting is part of the prominent escarpment formed by this rock. |
The exposure on the east side of the road into Beckbury is about 50 m long
and shows up to 3 m of calcareous marl conglomerate with pebbly sandstones
similar to those at Badger Dingle. At the base of the sequence are fairly
massive sandstones with distinct cross-bedding. These are finely laminated
and display multi-directional cross-stratification. Pebbles present in the
sandstone are themselves aligned to the cross-stratification; they are
varied in size averaging 50 mm but the occasional pebble is 100 mm. They
tend to form thin layers and are generally dipping at about 20°. Pebble
density is greater towards the base of the sequence and the shape is mostly
angular although there is some rounding. Thin lenses of red/brown marl are
distributed throughout the rock and generally form cavities. However approx.
400 mm from the base and 10 m from the old rectory gate is a prominent
recess of marl which can be easily examined. The whole exposure is full of
holes where pebbles have been weathered out. High up at the old rectory end
the sandstone appears to show evidence of possible channelling. The rock has
clearly been used for building in the village and the stone walls contain
interesting specimens. A collection of varied loose rocks has been assembled
beside the restored trough outside the village hall and includes fine
examples of Pentamerus Limestone the source of which is a puzzle! |
Conveniently beside a public road. |
RIGS Yes. Designation because it is a very good exposure of Helsby Sandstone
demonstrating a fluvial environment of deposition with varying energy
levels. It is one of few such exposures in the area. |
Sedimentology/Stratigraphy |
|
1315 |
SJ 7515 0575 |
Brimstree Hill - Shifnal |
Cutting (road/railway) |
Permo-Trias: Bridgnorth Sandstone and Kidderminster Conglomerate (Toghill);
from Sheet 153 which uses old nomenclature. |
The rocks here forms a hill. |
At Brimstree Hill weak cross-bedded Bridgnorth Sandstone is capped by much
stronger conglomerate and is exposed effectively at the roadside. Up to 2 m
of large-scale overlapping units are seen wedging out in different
directions. The rock is a uniform red millet seed-type sandstone typical of
wind-blown dune formation found in the Bridgnorth area. The units are finely
laminated and mottled in places. There is a very definite boundary with the
Kidderminster Conglomerate which appears to dip towards the south-west at
about 10°. Pebbles are small aligned in thin layers reflecting the
cross-bedding. Pebble beds reach ground level at the southern end of the
cutting which extends for about 40 m. This cap of conglomerate is very hard
and the pebbles are held in a strong purple/brown sandy matrix. This can be
compared with the outstanding site at the Hermitage in Bridgnorth. |
Open access by the roadside. |
RIGS Yes. Designation because the exposure clearly shows the boundary
between the two contrasting rock formations (Bridgnorth Sandstone and
Kidderminster Conglomerate) which in turn reflect contrasting former
environments of deposition. |
Sedimentology/Stratigraphy |
|
1318 |
SJ 549 268 |
Lee Brockhurst (rock cutting) |
Track/roadside |
Triassic: Sherwood Sandstone Formation: Wildmoor Sandstone (Toghill). Sheet
138 has old nomenclature. |
The f3 Formation; Wildmoor Sandstone; here forms a prominent hill; into the
edge of which an old lane was cut. |
Each side of the path are 4-5 m high vertical exposures of cross-bedded; red
soft sandstone. The exposure continues for at least 100 m and is easy to
examine and in good condition. Beige patches form the mottled effect which
gave this the former name of Upper Mottled Sandstone. The cross
stratification is impressive and multi-directional; with varied angles of
dip. The texture of the orange-red sandstone is fine and well-sorted with no
pebbles. However; there are horizons where the quartz grains are coarser and
apparently of the millet seed type. The exposure shows much vertical
jointing and several faults; there is one excellent example of a fault plane
with a trend of 120° which crosses the lane; able to be linked up as it
continues on the other side. Slickensiding is visible and there is slight
mineralisation. The strata consist of blocks; often having slipped and
giving a chaotic appearance; but there is a tendency for the layers to
become finer towards the top of the exposure. |
Easy access via a public right of way. |
RIGS Yes. Designation along with the sites referred to in RIGS report SJ
547268. Together these sites provide opportunity to examine Triassic
exposures which display a range of textural; and structural features. |
Sedimentology/Stratigraphy |
|
1319 |
SJ 548 267 |
Lee Brockhurst (river bridge) |
Cliff |
Triassic: Sherwood Sandstone Formation: Chester Pebble Beds (Toghill). Sheet
138 with old nomenclature. |
Steep cliff by the R. Roden. |
An exposure; up to 4 m high; extends for 25 m from the bridge. The whole
appearance is one of disturbed bedding produced by shifting currents. The
sandstone is coarser than Wildmoor Sandstone and a browner red in colour.
This is near the top of the Chester Pebble Beds. Pebbles are scattered
throughout the rock; being mainly angular and small (20 mm) but there are
pockets of more densely packed pebbles within the sandstone. The strata are
distinctly cross-bedded; some small scale; others larger and in places very
disturbed. There is much to suggest a relatively high energy environment.
Circular patches of softer sandstone occur with iron compounds forming rims
which stand proud from the softer rock. Elsewhere; swirling structures are
seen in the sandstone. Evidence of small scale faulting occurs and there is
a much more distinctive fault with trend of 200°; displaying slickensided
surfaces and mineralisation. Along the fault plane is a gap of 300 mm
occupied by a fallen block with a second fault a metre or so to the west;
its trend being 160°. This is a very interesting site when seen in the
context of the other sites at Lee Brockhurst. The face at this river cliff
appears to be the actual place where the major east/west fault crosses the
road. |
Via a non-public but well-used path to the river under the road bridge. |
RIGS Yes. Designation because it is an easily accessible large informative
exposure of Upper Chester Pebble Beds which provides evidence for palaeo-environmental
reconstruction situated where a faulted junction of f2 f3 and f6a occur.
The river cliff forms a major E-W fault. |
Sedimentology/Stratigraphy |
|
1321 |
SJ 560 286 |
Wixhill Lane - Weston under Redcastle |
Track/roadside |
Triassic: Sherwood Sandstone Formation: Wildmoor Sandstone (f3). Sheet 138
uses old nomenclature. |
North-west edge of the sandstone hilly area around Weston. |
Exposures here occur along a large part of the lane leading from the A49 to
Wixhill village. Exposures consist of overall near horizontal bright red
sandstone within which is low angle fine cross stratification. The partings
are wavy between the thin; hard beds and there is an appearance of rippling
and a scalloped effect. The height of the exposure is about 3 m. One
horizon; approx. 2 m up; and 30 mm thick; is noticeably recessed. The rock
is heavily jointed; some curved and parallel; especially towards the village
and under a garden wall on the south side; some of these show slight
displacement suggesting they may be small faults. On the south side there is
more massive bedding (up to 1.5 m thick) often with a definite boundary
where the latter are overlain by softer cross-bedded strata. |
Easy roadside access. |
RIGS Yes. Designation suggested because it is an extensive exposure of the
Wildmoor Sandstone with interesting sedimentary and tectonic structures
close to a significant fault zone. |
Structure and Sedimentology/Stratigraphy |
|
1323 |
SJ 594 289 |
Marchamley - Hodnet |
Quarry (disused) |
Triassic: Sherwood Sandstone Formation: Helsby Sandstone; and Mercia
Mudstone Formation: Tarporley Siltstones. Sheet 138. |
Southern edge of sandstone escarpment which borders Hawkstone Park. |
This report covers two adjacent sites. The Quarry: This disused quarry is
easily seen by the roadside and the massive white sandstone is striking. The
rock is soft yet stands up as a near vertical face. There is evidence of
large-scale cross-bedding. The texture is mainly uniform; the clean quartz
grains giving the appearance of beach sand. However; a few quartz pebbles
(20 mm across) were present; as were scattered harder nodules; possibly of
barytes-rich sand. In the westerly corner of the quarry; there is a fault
line and the light colour of the rock changes to red. Another interesting
feature at this end is what appears to be barytes cement which produces a
ridged effect; outlining the cross-beds. There are also diagonal cross
joints at angles of 120° and 060°. At the easterly end; the boundary between
f5 (Helsby Sandstone) and f6 (Tarporley Siltstones) can clearly be seen. The
red and grey coloration contrasts with the white sandstone beneath. The
Tarporley Siltstones are dipping gently NNE and occupy the top 2 m or so.
The lowest 750 mm comprise an esk bed; i.e. grey shaly sand with specks of
manganese dioxide; and this is succeeded by red flaggy sandstones. A
noticeable infilled joint or even a fault; cuts through the strata here;
widening at the bottom. It is filled with light; soft sandstone and is 0.5
m across. At the top of the succession; the grey esk bed thickens and has
collapsed into the joint/fault to fill it. The lane south from Marchamley:
The Tarporley Sandstones and Siltstones continue up the hill and it is
possible to walk up through the sequence which is described in detail by
Pocock in the Wem Memoir. There is a section off the road on the west side
where the strata is weathering purple/brown and is near horizontal. Red and
grey sandy mudstones are very thinly bedded; only millimetres thick and a
distinct micaceous sheen can be seen along the partings. The exposure here
is 3 m high and 15 m long; showing alternation of harder and softer beds and
the resultant differential erosion. The harder beds are more iron-rich.
Fallen blocks give good opportunity to examine fresh rock samples. In some
sandstone horizons pellets of mudstone are present. As one goes up the hill;
thicker sometimes mottled; mudstone layers are seen up to 750 mm thick which
are usually recessed below poriferous sandstone. Indeed the whole of this
road section consists of alternating harder and softer horizons within the
Tarporley Siltstones. There is clearly scope for detailed stratigraphical
study here. |
Both the quarry and roadside exposures are readily accessible. |
RIGS Yes. Designation because the site demonstrates stratigraphical detail
at the boundary between Helsby Sandstone and Tarporley Siltstones and allows
close examination of sedimentary succession; structures and facies change. |
Sedimentology/Stratigraphy |
|
1324 |
SJ 496 242 to SJ 496 247 |
Bilmarsh Lane - Middle and Broughton |
Track/roadside |
Triassic: Mercia Mudstone Formation: Mercia Mudstone (Keuper Marl). Sheet
138. |
Lane cut through Mercia Mudstone on N-facing slope. |
Mercia Mudstone is exposed for about 750 m on both sides of a lane; now a
bridle path. At the southern end; slightly micaceous red mudstone occurs on
each side. The rock is crumbly and there are thin broken layers of harder;
sandier mudsone alternating with more argillaceous material. On the day
visited; water washed over flat 'steps'; harder sandstone bands; in the
path. Very thin soft beds are overlain by a metre of the harder; sandy
mudstones; each bed about 40 mm thick; and dipping at less than 5° NW. The
exposures improve northwards with mudstone broken into small; rectilinear
blocks on an otherwise massive face with more sandstone on top. The mudstone
is partly fissile and the harder bands are said by Pocock to be ‘poriferous’.
Certainly small holes were seen in these horizons as were carbon fragments.
There are many joints and several small faults with minor displacement. At
the northerly end; exposures are higher; being up to 4 m on both sides of
the path; showing at least one good flat joint plane and sandstone layers up
to 100 mm thick. The extent and condition of this exposure is the result of
the presence of the alternating sandier; more resistant horizons. |
Public bridleway from Alderton. |
RIGS Yes. Designation because exposures of Mercia Mudstone are few and this
demonstrates the characteristics of the Formation very well. |
Sedimentology/Stratigraphy |
|
1325 |
SJ 360 139 |
Old Quarries - Loton Park - Alberbury |
Quarry (disused) |
Lower Permian: Alberbury Breccia ( see P. Toghill). Formerly classified as
Upper Carboniferous. |
Because of the relative hardness of this rock the … (entry incomplete) |
At the north end of the quarries there is an impressive face up to 8 m high.
Seen from a distance of 3 m the face looks massive and is vertical; having a
red/brown sandy appearance. On closer examination; there is evidence of thin
bedding and there is an apparent dip of about 15° NE. Large; sub-angular and
sub-rounded fragments; many of them grey in colour occur at particular
horizons. Many of the fragments are limestone and the presence of Lower
Carboniferous fossils; e.g. Lithostrotion corals and crinoids; support the
opinion that the source of these is Llanymynech Hill which lies a short
distance to the west. There are also noticeable fragments of a more
porcellaneous micritic limestone found in the same vicinity. Textures vary a
great deal; some horizons being very fine; others much coarser. There is
also evidence of cross-bedding reflected in the fragment pattern in the
rock. One interesting structural feature is what appears to be a
chimney-like joint tapering towards the bottom; with infilling of unsorted
material; roughly aligned ranging from fine marl to coarser sand and
breccia. Just round the corner in the same quarry is soft; mottled
red/yellow crumbling material which has accumulated around the harder rock
as if it has slipped and filled in available spaces. Some of the strata are
thick and containing large fragments on the base of the beds. Good examples
of grading can be seen. Differential erosion brings out variation in
hardness between the beds. Further to the SW; above and beyond the lake; are
many other exposures. One of these lies below the Deer Park wall and
consists of a 3 m high; rather weathered face extending for about 10 m.
There are very large limestone fragments visible in the breccia; some over
200 mm across; which in places demonstrate some alignment. One sees a jumble
of mixed fragments including sandstone; quartz; marly pellets and crinoidal
limestone. The matrix is calcareous and at times marly; there are also
cavities formed by the dissolving out of the limy matrix. Close by there is
an old limekiln; beautifully made and preserved; consisting of the Alberbury
Breccia. Small stalactites of limy deposits occur on the roof. Throughout
the Park the textures of the breccia are fascinating and would repay serious
study. |
Some of the exposures can be seen from public footpaths but for more
detailed study permission needs to be given by Sir Michael Leighton. |
RIGS Yes. Designation because the Alberbury Breccia is unique and here are
excellent exposures which provide opportunity for textural studies and
palaeo-environmental reconstruction. |
Sedimentology/Stratigraphy |
|
1326 |
SJ 364 132 |
Loton Deer Park - Alberbury |
Cutting (road/railway) |
Lower Permian: Alberbury Breccia (Toghill). No geological map. Formerly
classified as Upper Carboniferous. |
The highest sandstone of the underlying Keele Beds forms a bold escarpment
in the west of the Deer Park and this exposure is cut into the lower beds of
the Alberbury Breccia east of the top of the ridge. |
A good exposure on both sides of the track. The rock is up to 3 m high and
displays regular stratification. These beds are at a lower horizon compared
with those of the old quarries described in RIGS report SJ 360139 and
contain smaller fragments on the whole. The appearance of the beds here is
distinctly flaggy with even partings. Dip seems to be at 18° NE. The strata
are only about 30 mm thick at the top of the exposure but reach 150 mm
nearer the base. The stratification is not consistently regular; there being
irregular blocks; even a rounded one on the north side. The faces which are
broken by jointing; are quite badly weathered in places and textural detail
is less good compared with the faces in the old quarries. At the sides of
the footpath north of this site; Army activity dating from the Second World
War has left many loose blocks of breccia which can be examined and there is
a series of small rectilinear quarries along here which demonstrate a great
variety of textures and are of a convenient size for close up study. Here
the dip is about 10° roughly northerly in direction. Examination of true and
apparent dip can be carried out effectively in these small quarries. |
Easy access from footpaths but permission should first be sought from Sir
Michael Leighton; Loton Park Estate. |
RIGS Yes. Designation because the horizons in the cutting lie beneath the
exposures in the old quarries and the two sites together give a more
complete picture of the Formation as a whole. |
Sedimentology/Stratigraphy |
|
1327 |
SJ 561 287 |
Wixhill Farm - Weston under Redcastle |
Mine/adit |
Triassic: Sherwood Sandstone Formation: Wildmoor Sandstone (f3) (Toghill).
Sheet 138 uses old nomenclature |
Line of fault can be seen in separated exposures standing up abruptly in a
NNE/SSW direction. It forms the edge of the higher sandstone terrain. |
An exposed fault plane along the line of the Brockhurst Fault at Wixhill
where copper ore was worked from 1865-67. No real evidence of the copper ore
was seen but the fault plane shows slickensiding and alteration of the
Wildmoor Sandstone which here is harder and shows no cross-bedding. The
exposure is 2 m high and a black mineral is present on the surface; probably
manganese oxide. A few metres to the NE behind some vegetation; an exposure
across the fault zone is present. On the right; near-horizontal thinly
bedded strata suddenly become a vertical fault zone; broken and curving in
places. Thin parallel veins of barytes; 10-20 mm wide occur within the fault
structure. The altered sandstone is grey/pink/purple in colour and the most
heavily mineralised patch is at the left-hand bottom corner of the exposure.
Through the gate on the public footpath; a small old quarry is seen; its
rock surfaces very badly weathered; but the face is vertical and it is
clearly a continuation of the fault plane. From the lane which leads to the
main road 'The Mount' is visible; marking the position of the fault line;
here the Mercia Mudstones are faulted against the Tarporley Siltstones. |
Very close to a public footpath which goes through a seemingly disused
farmyard. |
RIGS Yes. Designation because this is an excellent exposure of part of the
Brockhurst Fault and associated features along which copper was formerly
mined |
Mineralogy/Petrology |
|
1328 |
SO 4415 9492 to SO 4434 9518 |
The Pike - Cardingmill - Church Stretton |
Bank |
Precambrian: Longmyndian: Stretton Series: Synalds Group |
A fine erosional feature of steeply dipping beds forming a hogs back ridge |
The ridges of ‘The Pike’ rise immediately from the NE side of the valley
road and seem precisely aligned to the local strike of N030E. The longest
extends for 430 m and the altitude of the crest increases from 225 m to 375
m AOD - an average gradient of about 1 in 3 so quite steep. Dip is
consistently to the NW but angle varies between 60° and vertical. The ridges
present an interesting case of development of a hogs back feature when the
dip significantly exceeds 45°. Retaining a hogs back terminology then the
scarp slopes face SE but its slope angle cuts across the bedding and this is
where most of the rock exposures occur. The dip slope faces NW but little
rock is exposed and the general tendency is also for the slope to cut across
the bedding. Above a junction 175 m from the road the stream runs between
the ridges and is so deeply incised in parts as to be an object lesson in
‘gulley erosion’. Above the stream junction it has cut through several
metres of drift into underlying bedrock. The Pike was selected as a GCR
site ‘because it contains one the most informative and well exposed sections
through the Synalds Formation’. Three localities are identified for
description (Wilson 2001) and all are easily accessible via the stream which
delimits the SE boundary of the exposures (see sketch map). This survey
confirms that all the features of this description are present and readily
recognisable. In particular:alternations of sandstone; often coarse; with
siltstone & mudstone; a very conspicuous cleavage is developed in the finer
grained purple silt and mudstones; visible lamination is planar or gently
undulating; occasional thick massive beds of sandstone occur; typically 0.5
metres thick; basal sandstone surfaces can be weakly erosional cutting into
underlying silt or mudstones. Differential erosion as between sand and
mudstone is strongly developed; especially at locality 1 Samples collected
for ‘slabbing’ show that sedimentary textures are perhaps more strongly
developed than the GCR descriptions suggest. Coarse sandstone is only weakly
graded but finer sandstone is notably admixed with layers of purple
siltstone/mudstone in a variety of laminations and banding which can be
markedly undulose; e.g. ripple or ripple drift lamination. Apparently
homogenous purple mudstone can show quite strong convolute lamination. The
alternations of beds is suggestive of turbidites and; for example; bedding
surfaces of the purple mudstones are usually grooved and fluted and
sometimes scalloped; although the latter seems to be an effect of
interaction between minor slippage and bedding. It is on these surfaces that
pit markings are common and examples interpreted as ‘rain-pits’ - although
looking more like ‘drizzle pits’ - are frequently found. Finally the
exposures at localities 1 and 2 (and elsewhere) are crossed by incipient
faults which produce effects demonstrating bedding competence; mudstones
become sharply bent developing an angular fold very similar to kink banding
whilst adjacent sandstones bend into gentle curves. |
Public access as part of Longmynd National Trust |
RIGS Yes. Designated both as an interesting and very explicit
Geomorphological feature as well as providing extensive and detail rich
sedimentary exposures. Really good exposures for sedimentary features plus
cleavage and some minor faulting/folding. |
Structure and Sedimentology/Stratigraphy |
|
1329 |
SJ 699 303 to 697 307 |
Cheswardine Road Bridge (Cheswardine canal cutting) - Sutton upon Tern |
Cutting (road/railway) |
Triassic: Bunter Pebble Beds (Chester Pebble Beds) and Upper Carboniferous:
Keele Beds |
Man-made excavation |
Best exposure of Keele Beds is just SE of the High Bridge where dull
red/purple sandstone layers alternate with soft red marls. There are
apparently (see Whitehead; p.17) five principal sandstone layers in this
section; the thickest bed is up to 3 m. Sandstone layers are variable in
thickness and can be seen wedging out among the marls. Recesses mark the
position of marl horizons below projecting sandstone. Unfortunately the
marls are very overgrown and disintegrate into mud although red and greenish
horizons are apparent. They are noticeably fissile. Fallen blocks of
sandstone and marl are found on the towpath and allow examination of fresh
surfaces so that sedimentary structures e.g. ripple bedding is evident. The
dip is mostly gentle and there seems to be a shallow anticlinal structure
between High Bridge and a fault which brings up the Chester Pebble Beds.
Visibility was poor on the day of the survey as fog shrouded the canal so
the strata on the east side was not easy to see! Between Cheswardine road
bridge and a fault which crosses the canal 100 m to the north; Chester
Pebble Beds are exposed. It is not easy to locate the exact position of the
fault but the approximate junction of Pebble Beds and Keele Formation can be
found. The best exposures of Pebble Beds occur closest to the fault where 5
m high massive sandstone with pockets and layers of mostly quartzite pebbles
can be seen. The brown-red sandstone beds (with large scale cross-bedding)
are up to a metre thick and contain variable densities of pebbles (some
aligned with the cross-beds; others scattered randomly). The pebbles show a
range of sizes from a few millimetres to 150 mm across mostly showing
evidence of rounding. At the southern end the beds are thinner (200-300 mm)
and contain more pebbles. |
By public towpath on the west side of canal. East side not easily reached. |
RIGS Yes. Designation because this is considered the best available site in
the area for the Keele Formation and particularly well demonstrates details
of channel form enabling interpretation of Late Carboniferous and early
Permian geological history. |
Sedimentology/Stratigraphy |
|
1331 |
SJ 689 327 |
Tyrley Locks |
Cutting (road/railway) |
Permo-Trias: Lower Mottled (Bridgnorth) Sandstone and Bunter (Chester)
Pebble Beds. Sheet 139. |
Man-made excavation |
Clear strata can be seen in the canal cutting just north of the Tyrley road
bridge extending for a distance of at least 300 m. At the southern end
where the locks begin a bright red soft sandstone is exposed with no
discernible pebbles but displaying excellent cross-bedding with units
dipping at angles varying from 20° to 30°. There is one particularly good
saucer-shaped dune type unit 9 m across. These beds appear to be wind-blown
deposits consistent with the Permian desert facies of Bridgnorth Sandstone.
In places there is distinct yellowish mottling including a thin 40 mm yellow
horizon. There is a gradual change to Chester Pebble Beds as thin layers of
pebbles begin to appear above the cross-bedded sandstone. Within the more
massive sandstone beds is what could be evidence of channelling suggesting a
change to fluviatile conditions. The pebble layers appear at the top of the
exposure and dip approx. N before reaching ground level. These layers are up
to 250 mm thick with scattered random pebbles of mixed sizes throughout the
sandstone at the northern end of the cutting. Sometimes the pebbles form
densely packed lenses. On the east side of the cutting similar strata are
also displayed but it is interesting to note that 0.5 m thick sandstone
beds; here nearly horizontal; occur opposite cross-bedded pebbly layers and
lenses. Max. height of the exposed strata is 4-5 m. |
Public canal towpath. |
RIGS Yes. Designation because there are extensive easily accessible
exposures of Permo-Triassic strata useful for interpreting variation in
facies and providing a complementary sequence to that at Cheswardine
cutting. |
Sedimentology/Stratigraphy |
|
1332 |
SJ 714 194 |
The Rockhole - Edgmond |
Quarry (disused) |
Permo-Trias: Chester Pebble Beds. Sheet 139. |
Pebble Beds form higher ground in Edgmond (and in the area around). Quarry
is cut into the hill. |
This is a first rate large site which has many interesting features. The
rock is essentially a coarse red sandstone; distinctly bright where the
faces are fresh. Within it are scattered pebbles; mainly vein quartz and
quartzite. At the base of the main north face are thick beds a metre or so
in thickness. Above 2 m there is a marked change to cross-bedded units; very
well displayed. These are mostly low-angle; 10°-15° and multi-directional;
indicating shifting currents. Within the cross beds the sandstone is finely
laminated and contains more pebbles showing some alignment. The boundary at
2 m is very definite. The pebbles are sub-rounded to angular; maximum length
being 70 mm. Because of recesses; it is possible to see the cross-beds in
3-D which is useful for working out palaeo-currents. At a height of about 5
m; at the top of the quarry face; the strata become more thinly bedded with
horizontal partings. Both vertical and oblique joints are evident as are at
least 3 faults with displacement of 40-50 mm. On the south side is an
interesting irregular collapsed fault or joint where cross-beds have steeper
dip. No evidence of mineralisation or slickensided surfaces were found.
Slump structures and graded lamination can be identified in the sandstone.
At the east end of the quarry are two major recesses at two levels. These
appear to correspond with the presence of a dark red/brown fissile; shaly
marl containing mica flakes and finely bedded with horizontal partings. At
the higher horizon; the marl was up to 0.5 m thick. |
A public footpath goes through and access to faces is excellent. |
RIGS Yes. Designation because it is an impressive site in the Chester Pebble
Beds; large accessible and demonstrates a variety of sedimentary structures
besides providing opportunities for interpretation so that palaeo-environments
can be reconstructed. |
Sedimentology/Stratigraphy |
|
1333 |
SO 767 994 |
Badger Dingle - Badger |
Cliff |
Triassic: Sherwood Sandstone: Helsby Sandstone (Toghill) |
Deeply cut dingle in the Worfe valley. The Helsby Sandstone forms a
prominent escarpment in this area. |
There is a 5 m high cliff of coarse red sandstone with pebbles roughly
aligned within the massive horizon and finely bedded cross-stratification at
its base. Under this and recessed is a 300 mm thick bed of red-brown
calcareous marl which displays an arching structure. In places the sand
deposition has caused distortion of the marl and swirls can be seen (see
photo). The pebbles 40 mm max. length are mixed with fragments of marl and
are mostly angular in shape. This is described as calcareous marl
conglomerate. There are also thin laminations of micaceous sandstone within
the thicker beds. A little further along the exposure to the west irregular
pebbly bands alternate with bright red purer weak sandstone with visible
light quartz grains. Several vertical joints (recessed and infilled) divide
up the face and there is possible faulting because the sandstone appears to
have moved and slumping is evident. Rock falls occur and loose blocks can be
examined at the foot of the cliff; these display interesting textures. There
are more exposures and interesting ornamental features e.g. grottoes and
caves in the rest of the dingle. |
Although the dingle is private a public footpath crosses it very close to
the exposure described. |
RIGS Yes. Designation because it is a clear exposure of the calcareous marl
pebbly sandstone and various structural features representative of the
Helsby Sandstone Formation. |
Sedimentology/Stratigraphy |
|
1336 |
SJ 6710 3325 |
Walkmill Nature Reserve |
Cliff |
Permo-Trias: Chester Pebble Beds. |
Part of a river cliff along the Tern. |
There is an exposure of massive cross-bedded sandstone about 4 m high and 80
m long. The cross-bedding consists of large scale units with sporadic
pebbles. The first cliff section reached from the entrance is rather
disappointing because of the deterioration of faces obscured by moss and
vegetation; and detail is hard to see; although a pebbly layer is seen at
the base of the cliff. The section improves further along and the bottom 1.5
m consists of a bed of randomly distributed pebbles recessed below a thick
sandstone unit. Pebbles can be seen along the layers of the cross-beds. The
sandstone is orange/red; showing fine laminations and some graded bedding.
The sedimentary structures are interesting; particularly some 'folds' in the
stratification which may be a form of slump structure. The texture of the
sandstone varies from being coarse to much finer. |
By public footpath in the nature reserve. |
RIGS Yes. Designation because of its potential as an example of Chester
Pebble Beds within a SWT Reserve and is included on the Nature Trail there.
(A badger sett has been excavated in the sandstone) |
Sedimentology/Stratigraphy |
|
1337 |
SJ 472 068 and SJ 473 067 |
Lyth Hill |
Natural exposure |
Precambrian: Longmyndian: Wentnor Group: Bayston-Oakswood Formation. Sheet
152. |
At the top and bottom of the south-facing fault scarp of Lyth Hill. |
The conglomerate is exposed in a band down the hill; the best exposure being
at the top; near to the footpath. This is at SJ472068. Along the footpath;
parallel to the road; coarse conglomerate begins to appear 45 m before the
main exposure. By the stile a large exposure is seen; height 5 m. It has a
smooth surface but is traversed by parallel pebble bands projecting from the
matrix in a N-S direction. These bands are packed with pebbles; size ranging
from a few mm to over 80 mm. Pebbles are sub-rounded to sub angular and are
of mixed composition but mainly of quartzite and vein quartz with a few
igneous ones. A few metres further along; there is a sort of grotto with
excellent conglomerate; the distinct bands are not so obvious here but there
is a possible fault at this site with evidence of disturbance and some
fragmentation of the rock. This is the Stanbatch Conglomerate; displaced
eastward by the Lyth Hill Fault. Below this very good exposure; the
conglomerate can be traced down the hillside and at SJ 473067 another good
but smaller exposure can be examined. Here many rhyolitic pebbles were
identified. |
Along public footpaths. |
RIGS Yes. Designation because this is an excellent; accessible; impressive
example of the Stanbatch Conglomerate within the Wentnor grits and
sandstones. |
Sedimentology/Stratigraphy |
|
1338 |
SJ 315 139 |
Bulthy Car Park - Wollaston |
Natural exposure |
Ordovician: Caradoc Series: Breidden Volcanic Group: Bulthy Formation: Bomb
Rock. |
At the foot of the northern-most end of Bulthy Hill; one of the volcanic
hills of the Breidden group (but in England!). |
Amazing large rounded boulders set in a massive face - one of those 'wow'
sites! The boulders or 'bombs' are between 300 and 600 mm across projecting
from the matrix of tuff. The height of the face is about 3 m and width of
this particular face 7 m or so. At the top the 'bombs' are densely packed
while lower down; they are less so but moulds of the ones that fell out are
a distinct feature of the exposure. The 'bombs' themselves are of andesitic
tuff. To the right of this face there is a fault showing slickensiding;
brecciation and infilling. The matrix rock is a grey; purple and granular;
with small tuffaceous fragments and shows clear stratification especially
where the number of 'bombs' is fewer. Near the west end of the quarry are
major bedding planes up to 5 m high dipping at approx. 60°. Here; the rock
is mainly tuff and there appears to be a N-S trending fault; the plane
dipping inwards at approx. 70°. The whole quarry is worth looking at and has
great potential. |
The lane goes through and the quarry is used for parking. Easy public access
makes the site a very useful one. |
RIGS Yes. Designation because there is nothing like this elsewhere in
Shropshire. The site admirably demonstrates an environment of explosive
vulcanicity and deposition of a water-lain conglomerate in submarine fans.
Can be studied along with the related rocks of the Breiddens over the
border. Fairly recent work on this formation was done in 1986 by Dixon. |
Mineralogy/Petrology |
|
1339 |
SJ 309 133 |
Bulthy Mine - Wollaston |
Mine/adit |
Ordovician: Caradoc Series: Breidden Volcanics: Bulthy Formation. No
geological map; refer to Toghill |
Off the path between Bulthy and Middletown Hills; SE side. |
There are several old mine shafts in the area and this one is clearly along
a fault. It is an excellent example of a fault with associated features.
Firstly; brecciated fragments form an encrusting layer on both sides of the
tunnel entrance; these vary in size from 150 mm across to very small angular
fragments. The rock type is an andesitic tuff. Secondly there are
slickensided surfaces and thirdly; much barytes mineralisation. This forms
an irregular vein 300-550 mm across. Going into the mine entrance the
mineralisation is seen to form the roof in which barytes crystals are
clearly visible. It was then realised that the miners had been extracting
barytes which had formed along the fault as a substantial mineral vein.
There were no signs of other minerals. The tunnel rises at a steep gradient
and can be entered to obtain better views of the barytes crystallisation.
This seems to be a significant fault crossing between Middletown and Bulthy
Hills. Along the footpath are other overgrown tunnels and spoil with loose
pieces of barytes scattered around. |
Public footpath just on the Shropshire/Powys boundary so access is open and
easy. |
RIGS Yes. Designation because this really is a magnificent fault in the
Bulthy Formation with excellent associated features and a good example of
former mining on the border. |
Mineralogy/Petrology |
|
1340 |
SJ 415 055 and SJ 414 052 and SJ 416 054 |
Habberley Brook - Pontesbury |
Stream/brook |
Precambrian: Longmyndian: Wentnor Formation: Bayston and Oakswood Group.
Sheet 152. |
Deeply cut narrow valley on east of Earl's Hill. |
The Lyd Hole is a spectacular site where a series of waterfalls; a chute of
water; and vertical sides of a gorge occur with a varied suite of Uriconian
volcanic rocks and Longmyndian sediments. Parts of the site are too
dangerous to allow close examination by many field workers; indeed it was
the present surveyer's 'assistant' who actually reached the heart of the
site! Even then; the rock surfaces are weathered; obscured by algae and
fresh rock samples not easily found. A pinkish rock; probably rhyolite was
seen and some rotten basalt; but the key boundary remained elusive in view
of the conditions. Above the waterfalls there is; apparently; one of the
few places in the Welsh Borderland where a contact between Western Uriconian
and Longmyndian rocks is exposed. The presence of Uriconian fragments in the
Longmyndian sediments here is strong evidence that the Western Uriconian
rocks pre-date the Longmyndian. The junction is of considerable historical
interest; having been the subject of an intense controversy between a number
of researchers. Near to the Lyd Hole along the Habberley Brook are three
more exposures of interest. At the 'entrance' to the gorge the rock is a
distinct conglomerate; the Radlith Conglomerate; earliest of the three bands
of conglomerate in the Wentnor Series in this area; it dips at about 60°
ESE. Then back along the brook at SJ 416054; a very good exposure of the
Oakswood Conglomerate can be examined on the east bank of the brook. Four
metres are exposed and large; up to 120 mm; densely packed pebbles occur
with very little purple/red matrix. This is the middle band of the three
conglomerates; it dips steeply; again in an approximate easterly direction.
At SJ 414052 steeply dipping pebbly grits (75°) with pebbles up to 10 mm are
exposed along the footpath. This is the fairly typical purple sandstone of
the Longmyndian. Harder bands alternate with softer; crumbling ones within
which are 3 mm layers of grey sediments. Calcite veining is evident in
places. This is a good exposure easily examined. |
The latter couple of sites are readily accessible as they are by the
footpath; but the Lyd Hole is difficult to reach especially when the brook
is high. Not to be recommended except for seriously fit geologists! |
RIGS Yes. Designation because of the SSSI designation and the importance of
the Uriconian/Longmyndian boundary and the use of this for unravelling the
Precambrian sequence. The assessment rating is very high because of this
despite the limitations of the Lyd Hole for general educational use (only
suitable for fit adults). |
Structure and Sedimentology/Stratigraphy |
|
1341 |
SJ 409 048 |
Earls Hill - Pontesbury |
Cliff |
Precambrian: Uriconian Volcanics. Sheet 152. |
Steep-sided hill rising to 320 m. |
The description takes the form of a traverse up and over the hill. At the N
end of Pontesford Hill is a disused quarry; now a scrap yard. It is rather
insalubrious but rhyolite is exposed. This has some potential but at the
moment is of limited value. A better exposure by the footpath near the
car-park shows brecciated rhyolite; with flow banding and spherulitic
structures dipping at about 40°. The best rhyolite is found near the top of
the hill fort where a NW-facing exposure up to 4 m high and 10 m across
displays fine; flinty rhyolite with good examples of spherulites. On the
steep climb through the plantation small exposures of rhyolitic tuff can be
seen but the path soon goes through dolerite/basalt. There is evidence of
vesicles and texture is fine so although dolerite is indicated on the
geological map; the rock mainly resembles basalt. Out in the open; at the
top of Pontesford Hill; are sporadic exposures of dolerite while at the
summit of Earl's Hill there are broken fragments of basalt. From the top;
extensive panoramic views allow excellent geological interpretation of the
landscape. Purple tuffs with suggestion of haematite and showing some
flow-banding; are exposed on the steep descent. Following the footpath NE
along the bottom of the hill a loose block of barytes; 0.5 m across; was
seen as well as vesicular rhyolite; the latter indicating explosive episodes
of vulcanicity. The best site on the hill is the impressive scree slope
where fragments of basalt have reached a state of near equilibrium below the
towering crags (SJ 410048). Blocks of scree material are up to 0.5 m across
and presumably owe their origin to freeze-thaw conditions towards the end of
the last Ice Age. It is interesting to note that above the path the scree
looks relatively fresh and has little vegetation whereas below it has the
appearance of a fossil scree; now colonised by mosses and other ground
cover. |
All the exposures mentioned are on or close to public footpaths and are
readily accessible. |
RIGS Yes. Designation for the whole hill as it is a significant faulted
inlier of Uriconian Volcanics with fair exposures illustrating the variety
of igneous rocks present. The scree slope is surely one of the few such
periglacial features in Shropshire. |
Mineralogy/Petrology |
|
1342 |
SJ 467 066 - extends from SJ 467 066 to 469 066 |
Lyth Hill |
Natural exposure |
Precambrian: Longmyndian: Wentnor Series. |
Exposures on fault scarp of Lyth Hill. |
There are many exposures on Lyth Hill (large and small); this description
only deals with the area between the given grid references. Here the Wentnor
Grit does not seem to be typical and appears to have been affected by the
fault. Because the grits apparently contain grains of various igneous rocks
the colour varies from greenish purple to blackish. Also the fault appears
to have changed the texture to one where the grains appear fused and
resemble an igneous rock. There is a series of good exposures at the foot of
the slope (up to 6 m high) but there are distinct signs of fragmentation
resulting from faulting. Bedding can be discerned and is steeply dipping
towards the east. Patches of purple and pink occur and there are several
quartz veins. The rock is essentially a coarse grit with a few scattered
pebbles. Joints and fractures give a shattered appearance; there being
several small faults. About 30 m from the west end are slickensided surfaces
associated with quartz mineralisation and brecciation; these are oblique to
the main Lyth Hill fault and have a trend of 120°. As the footpath climbs
round the fence at the west end loose fragments of more typical purple grit
occur and behind the fence small exposures of this are found in the trees. A
quartz vein up to 30 mm thick was seen in the purple/pink gritty sandstone
in which were scattered pebbles up to 3 mm in size. |
Public footpaths in the country park. |
RIGS Yes. Designation because this site while not being the clearest and
easiest to use is important for interpretation of the geology of Lyth Hill
and the effect of faulting in this vicinity. It is recommended that the
whole of Lyth Hill should be a RIGS. |
Structure |
|
1345 |
SJ 583 293 |
Hawkstone Obelisk |
Cutting (road/railway) |
Triassic: Mercia Mudstone Formation: Tarporley Siltstones. Sheet 138. New
nomenclature from Toghill. |
South scarp slope of sandstone ridge. |
Here there is a distinct boundary between the massively bedded f4 Helsby
Sandstones found in much of Hawkstone Park and the overlying thinly bedded;
mottled Tarporley Siltstones; formerly Waterstones. The boundary is marked
by a recess. The siltstones dip north-north-west at 7° and a detailed
section through the various horizons can be studied from south to north.
Height of the exposure is about 4 m. Above the Helsby Sandstone is the Esk
Bed; loose sand with barytes crystals; according to Pocock; although the
present surveyor was not able to identify it; mainly through lack of time.
However; flaggy; reddish sandstone; sometimes rubbly and calcareous was
clear to see with red siltstone showing evidence of mica flakes. A hard
sandy horizon about 2 m from the ground was distinctive. Regular parallel
jointing; also parallel to the dip produces a 'bay/promontory' effect here.
Besides the red beds are alternating bands of grey. This description fits
Pocock's 6 ft sandstone layer immediately above the Esk Bed. Given more
time; a more detailed description of the overlying beds could have been
done. |
Follow a path east from the Obelisk for about 300 m. The main part of the
cutting is in Hawkstone Park. Avoid the land beyond the 'private' notice. |
RIGS Yes. Designation because here is a clear; significant boundary between
Helsby Sandstone and Tarporley Siltstones and an excellent section through
the latter. |
Sedimentology/Stratigraphy |
|
1346 |
SJ 575 294 |
Hawkstone Terrace |
Cliff |
Triassic: Sherwood Sandstone Formation: Helsby Sandstone (Grinshill
Sandstone); overlying Wildmoor Sandstone (Upper Mottled Sandstone). Sheet
138 (older nomenclature f4 over f3). |
Cliffs of the scarp slope of Hawkstone escarpment. |
The footpath along the Terrace runs parallel to impressive cliffs of pale
Grinshill Sandstone; the upper part of which shows excellent cross-bedding.
Traces of copper show up green; and near the Swiss Bridge discrepancies in
dip direction and angle indicate a fault which can be seen a little further
on beside the path. Here the sandstone looks rubbly and has weathered to
produce a pseudo-spheroidal effect. At the Retreat; soft barytes-rich pale
sandstone forms the back face of this feature; the sand reminiscent of beach
sand and the barytes nodules making an interesting texture. At this point
along the terrace are impressive parallel fault planes with green and orange
mineralisation; trending NNW/SSE. Slickensiding suggests lateral movement;
possibly right to left. A series of faults can be studied between the
Retreat and Indian Rock. Fox's Nob is a pinnacle of Grinshill Sandstone with
a flat slab at the top; consisting of irregular; massive blocks. Barytes
forms discontinuous layers; 20 mm thick standing proud from the surface.
Beautiful cross-bedding occurs here; the dark minerals (iron oxide?)
emphasising the structure. From this point onwards a red sandstone makes its
appearance beneath the pale rock. There is no clear break between the two
but the red sandstone seems to belong to the underlying Wildmoor Formation;
seen at the base of the Red Castle and outcropping over a larger area in the
east of Hawkstone Park. Along Reynard's Walk 10 m of the latter sandstone is
exposed. High angle; large-scale cross-bedding with barytes following the
partings occurs here. About 1.5 m from the base is a horizontal plane below
which the soft; well-sorted; medium sandstone with no pebbles; is recessed.
There are barytes 'flows' up to a metre long looking like mini frozen
waterfalls. The faces described in this report are but a few and there is
much scope in Hawkstone to make further studies. |
By footpaths within Hawkstone Park (entrance charge applies). |
RIGS Yes. Designation because the sedimentary and tectonic structures are of
excellent quality and the cliff formations are very impressive. Also; the
change from Wildmoor to Grinshill Sandstone can be observed in several
locations. |
Structure and Sedimentology/Stratigraphy |
|
1347 |
SJ 573 298 and SJ 571 295 |
Hawkstone; Grotto Hill and Red Castle |
Cliff |
Triassic: Sherwood Sandstone Formation: Helsby Sandstone (Ryton and
Grinshill Sandstones) overlying Wildmoor Sandstone (Upper Mottled
Sandstone). Sheet 138 (older nomenclature f4 over f3) |
'residual cliffs' at west end of Hawkstone escarpment. |
At the top of Grotto Hill; white/buff sandstone (Grinshill) is exposed as
spectacular cliffs. The top 3-4 m consist of irregular cross-bedded blocks;
the inclination being uni-directional towards the SW. Just below the
cross-stratified blocks is a smoothed; concave; copper-stained surface.
Below the copper staining the sandstone bulges out before over-hanging
softer more crumbly material. Height must be about 50 m with a sheer drop.
Underfoot at the view-point on Grotto Hill; fine 'flowing' laminations in
the sandstone can be seen and there are irregular white crystals of barytes
which also fills small joints. This makes an interesting texture. The beds
underfoot are seen to dip WNW at about 20°. Near the entrance to the Grotto
itself; formerly a series of caves and passages associated with copper
mining; a fault plane is evident and the sandstone; fairly fine-grained
here; has some iron-rich horizons. From the view-point; the Red Castle; a
small outlier can be seen clearly; of particular note is the colour change
in the rock which reflects the red Wildmoor Sandstone at its base passing up
into the light Grinshill Formation. Because the remains of the castle are
unsafe it is not permitted for the public to climb up to it at present.
Inside the grotto; old copper mine tunnels have been made into a 'feature'
and green staining and surface encrustation of copper compounds are still
apparent on walls and ceiling. A torch is recommended! One exit leads down
the cliff via 'the cleft' where more thinly bedded sandstone forms 7 m high
walls either side of a steep; narrow path which follows a fault plane.
Despite moss; some rough stratification is visible; cross-bedding; infilled
diagonal joints and the whole face has a rubbly appearance. |
By public footpaths in Hawkstone Park (entrance charge applies). |
RIGS Yes. Designation because this is a spectacular; accessible site which
demonstrates textural and structural features of Grinshill Sandstone and
provides a good view of the transition to red Wildmoor Sandstone beneath.
Link with copper mining is an added feature of interest. |
Mineralogy/Petrology |
|
1348 |
SJ 2690 2205 and various others mentioned in the text |
Llanymynech and Blodwell Rocks |
Quarry (disused) |
Lower Carboniferous: Carboniferous Limestone: Lower Limestone. Sheet 137. |
South-east flank of Llanymynech Hill and crest of Blodwel Escarpment. |
Although the best exposures in this area are in Powys and so are not
reported on; the sites described here are good and show impressive vertical
faces in the disused quarry within the Nature Reserve at the grid reference
indicated. The quarry face rises to over 30 m and the strata look horizontal
but this is apparent dip; the true dip being mostly NE but varies. At the
base of the cliff; the beds are thick (0.75 m) with clear stratification;
texture is fine and flinty; the rock being dove grey in colour. There are
thin shaly horizons which tend to disintegrate and sometimes harder; more
slaty partings. Near vertical joints divide the beds into blocks. Apparently
there is evidence of dolomitisation along some of the joints. In these lower
beds there is a saucer-shaped structure thinning out at the edges and about
5 m across; whether this is a small synclinal structure or a sedimentary one
was not clear. Above 5-6 m the rock looks pink and the beds are more
variable in thickness; some being flaggy. Coarsely crstalline limestone was
noticed but the height of the cliff did not allow close examination of the
higher beds. It is possible to walk from here into Wales and examine the
better known sites at SJ 265 217. 2. From here walk along the Blodwel
Escarpment. The path takes the crest but various small faults cross the
escarpment and are interesting to examine. At SJ 2655 2270; exposures of
limestone with close parallel dip joints are seen; here the dip is about 40°
ENE but on the other side of the path; it is 10° SE. This seems to be the
result of faulting; evidenced by a cleft a few metres along the path; where
slickensiding and brecciated rock occur. A central wedge appears to have
dropped and movement is greater on the south side. Trend of fault is E-W.
This seems to be related to the copper mining in this area. There are other
faults cutting across the escarpment; notably one at SJ 268 233 where the
fault leads to two adits at different levels. Here are big cliff faces with
dark-weathering; thick (300 mm to over a metre); strongly jointed limestone
beds with clay-shale partings. The dip appears to be south-easterly.Views
here are magnificent towards the Welsh mountains. There is plenty of scope
to explore this area in more detail! 3. Just off the footpath at approx. SJ
274 234 there is an interesting exposure 4-5 m high and extending for 50 m
or so comprising limestone beds of varying thickness (0.10-0.75 m) succeeded
by rubbly limestone which looks like a breccio-conglomerate; roughly
stratified and dipping SE at 10°-20°. It is the latter that is unusual; the
fragments are held in very little chemically precipitated cement and the
rock has a nodular appearance and is poriferous. Large; discoid; colonial;
rugose corals 300 mm across; are found within these beds; although some are
upside down suggesting they have drifted there after death. The fossils have
recrystallised and so much of the detail has been lost but they are mostly
Lonsdaleia floriformis with a few single corals; probably Dibunophyllum. |
All these sites lie on or near to public footpaths so access is open. |
RIGS Yes. Designation for the sites as a whole because they provide a good
range of exposures in the Lower Limestone showing a range of sedimentary and
structural features as well as evidence of the former copper mining history
of the area and are all on the English side of the border. |
Fossils and Sedimentology/Stratigraphy |
|
1350 |
SJ 495 073 and see location map |
Condover Pit; Bomere; Shomere and Betton Pool |
Quarry (disused) |
Quaternary: fluvio-glacial sands and gravels |
Hummocky landscape with depressions and pools. |
The landscape is one of hummocks; depressions (often marshy or water-filled)
and sandy ridges. The sand shows through grass-covered low hills. Bomere
Pool and the others occupy natural depressions in the glacial drift left by
ice-sheets some 15 000 years ago; they are steep sided and can probably be
classed as kettle hole lakes. Groundwater levels indicate that Bomere Pool
and probably the others are perched features and isolated from groundwater
in the underlying sands and gravels. There is a close correlation between
the landscape features and the contour lines of the 1:25 000 OS map. The
Trout Pool (SJ 501 076) seems to be a kettle hole deepened and restored
artificially for fishing and recreation and there is a seepage channel at
its low point flowing SE intermittently. Above this pool is a small damp
depression. At the Condover Sand Pit; Norton Farm; the site is in a
continuous state of change and as such it is not possible to identify a
RIGS. There are many features of geological interest; however; from deep
steep-sided kettle holes; including the place where the Shropshire Mammoth
was discovered; now a clean water lagoon; to unstable banks of pure sand
inter-bedded with gravels. The characteristically hummocky topography is a
reflection of the complex sequence of underlying glacial sands; gravels and
clays which lies below the surface. The thickness of superficial deposits is
dependant upon the surface elevation and variable elevation of the Keele
Beds below the drift and varies from 10 m to over 38.5 m. |
A lane and public footpath crosses the hummocky terrain and goes along the
north side of Bomere Pool and Betton Pool. Bomere Wood and Shomere Pool are
on private land. Access to the sand and gravel workings need prior
permission from Hansons. |
RIGS Yes. Designation because this is a classic landscape of glacial
deposition with kettle hole lakes next to a working quarry where more
detailed sections of sands and gravels can; with permission; be clearly
seen. It is also the place of discovery of the Shropshire Mammoth. |
Geomorphology/Landscape |
|
1356 |
SO 212 784 |
Coed-yr-Hendre |
Quarry (disused) |
Silurian; Dalamanella lunata beds acc. Earp (1940); equivalent to Cefn
Einion Formation of BGS |
|
This roadside quarry presents a joint plane trending north with a uniform
dip of 15° towards 355 (N). The exposure is clearly separated into a lower
and upper part by a disconformity. In the lower part the grey siltstones are
hard and flaggy with much sedimentary detail (e.g. pinch & swell) suggesting
deposition in an energetic environment perhaps even within the wave base.
There are calcareous bands. Most significantly the rock surface carries a
distinctive sheen (or polish) only seen once before by this surveyor (n the
upper Cefn Einion Formation at Bury Ditches immediately below the
Platyschisma Shales). This is consistent with Earp (1940) who maps this
quarry close to the same Platyschisma Helicites beds. Further confirmation
is found in the abundance of fossils (wholly as casts and dominated by
Salopina lunata and pentagonal columnals associated with borings of Salopina
shells). Above the plane of disconformity the rock is quite different;
seemingly a brown (decalcified?) fine sandstone up to 2 m thick and most
remarkably compacted by slumps so that there is development of ‘spherical
jointing’. However surface textures confirm the latter origin is as a
consequence of slumps. |
From Llanfair Waterdine take the road heading NW along the valley of the
River Teme. After 4 km this turns north and the quarry is to be found just
beyond the end of a small plantation on the RHS |
RIGS Yes. RIGS designation proposed since this as a possibly unique and
certainly significant exposure. Good sedimentary structures fossils and
slumping phenomena near or at the Ludlow/Pridoli boundary |
Sedimentology/Stratigraphy |
|
1364 |
SO 233 820 |
Garn Wood |
Quarry (disused) |
Silurian; Cefn Einion Formation |
|
Quarry lies on north side of B-road (B4368) and its floor forms a small
lay-by. Rock is a clearly bedded siltstone/sandstone sequence variously
flaggy and massive. It is slightly calcareous with occasional patches of
brownstone suggesting fossil coquina. Size of the main face is some 12 m
wide and up to 5 m high. However the principal interest is the dip and
evident folding. From right to left there is a steep 45° dip to the right
(west) punctuated by a 3 m wide sigmoidal fold in which dip is locally
vertical. Ref 1 shows a dip arrow at this locality of only 24° to the WNW.
Further (at the extreme left) the dip is seen to ease (becoming only 10° W)
suggesting that the quarry lies on the easterly limb of a syncline. Some 150
m west along the B-road is a small cottage behind which are steep vertical
quarried faces showing a persistent dip 45° west and a distinctly turbiditic
texture. This could imply that between quarry and cottage is a now eroded
anticline. Irrespective of such speculation the quarry and cottage exposures
are considered illustrative of the nature and scale of folding within the
zone of the Clun Forest Disturbance |
Quarry affords a lay-by on the north side of the B4368 going west from the
village of Newcastle and is found in the first large area of trees some 1.6
km (1 mile) west of Newcastle. |
RIGS Yes. RIGS designation for its demonstration of folding and inference of
a syncline/anticline relation. |
Structure and Sedimentology/Stratigraphy |
|
1365 |
SO 235 801 |
Hill House (SSW) |
Quarry (disused) |
Silurian; Cefn Einion Formation |
Locality lies on the SE flank of a N-S ridge called Hurgin on the base map
of Ref 1. A complementary exposure (somewhat higher in the sequence) lies on
the NW flank at SO 233 808 |
Quarry presents faces up to 4 m high in a number of sections totalling some
50 m. Bedding is near horizontal and is variously thin bedded and massive;
siltstones and fine grey sandstones. Some sedimentary detail is evident. The
floor of the quarry undulates but is in the main grass-covered so there is
little talus. Most significant is that this exposure is mapped (Ref 1) as
lying just above the Knucklas Castle Formation which implies some degree of
transitional character. The finding of a cephalopod cast would seem to
confirm lower Cefn Einion Formation. It is also noted that the site with its
tectonically undisturbed bedding lies just to the SE of the Clun Forest
Disturbance zone; nearest exposures of which are at Garn Wood and possibly
on Dowke Hill. |
Nearest sizeable village is Newcastle from where one would take lanes
heading south to Llanfair Waterdine. Hill House is 500 m south of
cross-roads at Stoney Pound; the quarry site is a further 400 m on a bend
trending SW. A short path on the north side of the road at this point leads
immediately to the quarry |
RIGS Yes. RIGS designation for its demonstration of stratigraphy and
tectonic disturbance |
Structure and Sedimentology/Stratigraphy |
|
1366 |
SO 240 778 |
Bwlch to Cwm-cold |
Quarry (disused) |
Silurian; ?Bailey Hill Formation |
|
This locality comprises a 300 m long E-W section in which observations of
dip reveal strong folding into a synclinal and anticlinal form. This
description starts at the most eastern of the cottages at Cwm-cold (SO 243
778) where a quarry is visible to the north beyond some outbuildings.
Apparent dip is some 50° west; real dip is probably to NW at a value
exceeding 50°. Proceeding west along the access lane to these cottages: (a)
after 70 m two exposures on the left (one near the lane the other a higher
quarry) where dip is now 30° but to the east; (b) after a further 40 m a
second quarry shows apparent dip 45 to 55° also to the east; (c) at the top
of the lane (ca. 250 m from the cottages) and behind old buildings on the
right is exposed highly distorted strata associated with a fault; (d) just
beyond is a small knoll showing horizontally bedded rock; (e) finally (at
Bwlch) as the lane begins to descend there is a quarried area on the right
in which general dip is now 10° NW although there are sigmoidal distortions
containing segments of higher dip. Rock here is finely bedded blocky
siltstone with some lamination. Excellent kink bands are developed in these
thinly laminated mudstones. The occurrence here of such folding is
consistent with the main expression of the Clun Forest Disturbance described
by Woodcock (1984) for this local area to the north-west of Knighton. |
Bwlch lies about 1 mile north of Llanfair Waterdine on the road heading
north to Newcastle. The lane to the cottages at Cwm-cold branches off to the
right or can be reached via a footpath through trees on the right hand side |
RIGS Yes. RIGS designation for its demonstration of tectonic disturbance
(syncline/anticline) in relation to the Clun Forest Disturbance |
Structure and Sedimentology/Stratigraphy |
|
1367 |
SO 252 842 |
Rhespass |
Temporary excavation |
Silurian; Bailey Hill Formation (Ref.1) |
A confined valley with stream giving a view NW; very suggestive of a long
approach to a col or pass |
This locality comprises a 300 m long E-W section in which the excavation on
the north side of a bridleway just short of some farm buildings is a
fantastic section through what can only be described as a ‘crumple zone’.
The exposure comprises a single 8 m high face extending without interruption
for 50 m. At the right hand end is a sequence of strong folds (anticline and
syncline) with near vertical limbs and sharp fold hinges on a 3 to 5 m
scale. This pattern of distortion continues all the way to the left with the
central part partly hidden by vegetation. At the extreme left hand end is a
structure strongly suggestive of a thrust where a low angled plane of
disturbance appears to ride over and drag the top of a relatively
undisturbed low buttress. That the excavation presents the response to
extreme compression is the obvious explanation. The locality lies some 1 km
NW of the vertical dips of Graig Hill but nevertheless would seem to lie
within the zone of the Clun Forest Disturbance. |
From Bridge Farm at SO 259 840 an initially straight bridleway leads just
north of west to reach the excavation after 650 m. This bridleway continues
along the valley outlined under Geomorphology |
RIGS Yes. RIGS designation for its demonstration of tectonic disturbance in
relation to the Clun Forest Disturbance |
Structure and Sedimentology/Stratigraphy |
|
1369 |
SO 255 872 |
Churchtown Hill Mainstone |
Quarry (disused) |
Silurian; Bailey Hill Formation |
Steep hillside with outstanding ridge exposing rock and adjacent hollow |
This locality embraces a quarry section and at least 3 large natural
exposures. Of most interest are tectonic features with large dip angles and
strong faulting possibly demonstrating fault drag. A detailed ground survey
was carried out on a second visit - copy attached. This confirmed that
locally there is a consistent dip direction to the SW with value of 45-55°.
Such values are common in nearby exposures (e.g. quarries in Mainstone) and
are assumed to be due to large scale folds within the zone of the Mainstone
fault and/or the Clun Forest Disturbance. The natural exposures and the
quarry show mainly planar laminated dark grey siltstones and fine sandstones
typical of Bailey Hill Formation. Within the quarry the apparent dip in the
east-west aligned face changes swiftly from 45° to 80° near the fault which
is exposed at the western end of the face. There are major bedding
contortions within this fault (see sketch) which are here interpreted as due
to fault drag effects on the assumption that the fault downthrows on its
western side |
From Mainstone take road heading due west. A quarry with lay-by occurs in a
re-entrant after 2 km |
RIGS Yes. RIGS designation for its demonstration of fault drag; but expert
second opinion is sought to compare with other possibly similar exposures in
the vicinty |
Structure and Sedimentology/Stratigraphy |
|
1375 |
SJ 626 167 |
Longswood Farm - Crudgington |
Quarry (disused) |
The Hillock is Triassic; Sherwood Sandstone Group; Kidderminster Formation
(pebble beds); The surrounding ‘plain’ is Permian; Bridgnorth (Lower
Mottled) Sandstone ref. 1 (Solid Edition); This unconformity is regionally
taken as the Permian/Triassic boundary |
The hillock of height 25 m above the surrounding plain would seem to
represent a relic of Kidderminster Formation Pebble Beds overlying an
alluvium covered plain of Bridgnorth Dune Sandstone. |
The quarry face is 80 m long east to west and up to 10 m high. Dip is 7°
west. It looks over a small bend in the course of the River Tern the
opposite bank of which is vegetated. Exposed rock is a ‘big river’
cross-bedded sandstone; only locally pebbly in lower half. There are some
darker siltier lenses and greenish bed parallel streaks (these could be
interfingered aeolian dune sandstone from underlying beds). There is a
splendid set of about 10 swell faulted joints dipping 65° to east giving an
antipathetic joint set (see sketch). |
The site is adjacent to a public footpath which runs between the Weald Moors
on the A442 and Longdon on Tern on the B5063. Both roads run north from
Shawbirch. Note that the site is used for motor-cycle scrambling. |
RIGS Yes. Designation because shows both tectonic & sedimentary features. |
Structure and Sedimentology/Stratigraphy |
|
1377 |
SO 802 951 |
Upper Ludstone |
Cutting (road/railway) |
Triassic; Keuper Series; Lower Keuper sandstone (ref. 1); Sherwood Sandstone |
Road Cut in new by-pass on B4176 road to Dudley ascends a west facing scarp
in which rocks dip moderately (10 degrees) to east. |
On north side of cut exposure is long and clean and access is safe but
somewhat noisy from passing traffic. Because of the easterly dip the strata
forms terraces up the bank and a total thickness of about 25 metres is
exposed. It comprises all grades from siltstone up to pebbly sandstones
(generally strong) of a purple colour and clearly indicative of deposition
in a range of energetic environments. There are small faults lithic
calcareous intraclasts and exotic pebbles with varied diagenetic colours and
cements. |
There is parking in a gateway at the foot of the bank on the north side; it
is only a short distance to a large and prominent road house. |
RIGS Yes. Designation because this is as an exemplary exposure in the
Sherwood Sandstone |
Sedimentology/Stratigraphy |
|
1381 |
SO 234 931 |
West Penyllan |
Quarry (disused) |
Silurian; Wenlock Series; Nantglyn Mudstones Formation; Gyfenni Wood Shales
Member (ref 1) |
Quarry excavated in south facing hillside which is perhaps steepened by a
palaeovalley cut. |
Quarry exposes some 8 metres of thin bedded shaly siltstones with some 100
mm thick shale partings. Dip is 5° SW according to ref 1. There are a few
calcareous septarian nodules. The Gyfenni Wood Shales are described as
hemipelagite (a dark grey silty laminate) (Cave Hains & White in ref. 2 page
87) forming a background deposit during Wenlock and early Ludlow times;
fossils are pelagic notably graptolites & orthocones. Monograptids are
plentiful at this locality. |
Quarry lies on the north side of the A489 Churchstoke to Kerry road some 4
km from Churchstoke. |
RIGS Yes. Designation because this is as a good example of the Gyfenni
member and the only Shropshire locality for this unit |
Sedimentology/Stratigraphy |
|
1382 |
SJ 391 023 |
Lower Vesson |
Track/roadside |
Ordovician; Tremadoc Series; Habberley Shale Formation (refs. 1 & 2); note
that no intrusions are marked on ref. 1 at this locality |
|
Exposures (extending for about 30 m) show steeply cleaved micaceous silty
claystones; a dark diorite showing pyrite is intruded; this weathers to a
brown sandstone like texture. The shale at the contact is altered to a pale
hornfels and is spotted to resemble a pellet grainstone. More hornfels
variety could be revealed by clearing and excavating. A quartz vein is also
present. Overall the outcrop probably extends for about 100 m along the
track which is part of a mountain bike circuit. |
From Snailbeach Mine a road leads east up the valley to Upper Vessons farm &
church from whence good public tracks and Forestry biking trails continue
eastwards to Lower Vessons. The site is approx. 300 m NNW of Lower Vessons. |
RIGS Yes. Designation proposed as a site showing thermal metamorphism of
fine grained sediments |
Mineralogy/Petrology |
|
1383 |
SJ 520 124 |
River Severn (Monkmoor) |
Stream/brook |
Carboniferous; Upper Coal Measures (Westphalian C); Ruabon Marl (ref. 1) |
Natural crags and river bed shoals best seen at low water |
About a 20 m length of section is exposed where the river runs north to
south. This lies on the outside of a river bend and lies mainly in the river
bed extending about one half river width. It is therefore best examined at
times of low water levels. Upstream is a modest dip to the north. At south
end of section are some 7 m of clays; variously purple to blotchy green.
Scarce pieces of conglomerate; intraclasts; calcareous or dolomitic; and
‘stirred’ sandy lenses are occasionally exposed by landslips off the bank.
The middle 10 m show fine sandstones with ripples and erosive bases and
sub-equal redder siltstones. The top 3 m comprise siltstone sandstone and
breccia lenses. There may be sandstones under the bridge piers. |
From the suburb of Monkmoor there are various ways to reach the west bank of
the River Severn and walk downstream along public footpath to the railway
bridge. The river bed rocks are below the Railway Bridge. This locality
should not require any particular permissions to visit. |
RIGS Yes. Designation proposed as a rare example of a locality showing
detailed lithology of the Ruabon Marl |
Sedimentology/Stratigraphy |
|
1384 |
SO 538 734 |
Poughnhill (Tinker’s Hill/Caynham Camp) |
Quarry (disused) |
Silurian; Ludlow Series; Whitcliffe Formation (Ref. 1) |
Pronounced ridge due to faults bringing harder rock to the surface |
Near Bradnor Hill (Kington) the Leinthall Earles Fault branches east from
the Church Stretton Fault System and runs east of north-east to Titterstone
Clee and beyond. Its downthrow to the north-west is consistent with the
throw of the Church Stretton fault but at Overton a second branch is formed
which downthrows to the south-east (BGS 2000). As a result a horst-like
feature is developed in the sense of Park (1997; fig. 2.8). This throws up a
long narrow outcrop of Ludlovian and early Pridoli rocks through the cover
of Raglan Mudstone so forming a 4 km ridge south-west to north-east from
Tinker’s Hill to Caynham Camp. Beyond Caynham the outcrop is abruptly
terminated by a cross fault downthrowing to the north-east. The Ledwyche
Brook cuts through this ridge and appears to be a misfit stream within the
current valley and probably hosted the River Corve prior to capture by the
Teme in the late stages of the Devensian. The quarry at this site (opened on
the western side of the gap) was for building stone. It exploited the
outcrop of Whitcliffe Formation and was of considerable size; the main face
is some 200 m long. All of this is now degraded and vegetated save for one
pillar like section 6 m high and 8 m wide which reveals clean rock. This
section offers an alternating sequence of smooth faced decalcified siltstone
up to 100 mm thick and rough surfaced finer grained siltstones up to 300 mm
thick; there are occasional partings less than 10 mm thick. There is much
sedimentary detail including laminations and minor erosion surfaces. The
sequence resembles the Upper Whitcliffe Beds in the dingle above the
Whitcliffe type section (SO 509 741). Fossils are assessed as being common;
one obvious bedding plane showed Salopina lunata
and Protochonetes ludloviensis
inside the smooth faced facies. The walk (east) up to Caynham Camp is
instructive for the views and appreciation of the context of the Ridge in
relation to the anticline beneath Mortimer Forest. |
Exit Ludlow via the Sheet Road; continue straight over the A49 bypass and
through the village of Sheet. The road next enters a short defile where
parking is most convenient (opposite a waterfall over a weir in the Ledwyche
Brook on the left-hand side). On the opposite side a footpath sign indicates
a direction over the ivy-covered quarry floor towards the quarry section.
The quarried area is crossed by a public footpath which gives adequate
access. The walk (east) up to Caynham Camp is instructive for the views and
appreciation of the context of the Ridge in relation to the anticline
beneath Mortimer Forest. |
RIGS Yes. Designation proposed primarily for its illustration of the
geomorphology of a ridge developed as a consequence of a splay fault (part
of the Church Stretton fault system). The Ledwyche Brook appears to be a
misfit stream within the current valley and probably hosted the River Corve
prior to its capture by the Teme in the late stages of the Devensian. The
similarity of the visible exposure to the Whitcliffe at Ludlow is also of
interest. |
Geomorphology/Landscape |
|
1396 |
SO 468 955 |
Hough's Coppice |
Track/roadside |
Silurian; Wenlock Limestone Formation; Tickwood Beds (as a member) (Ref.
1) |
Hillside below westerly flank of Caer Caradoc and showing slope angle
determined by underlying lithology |
From the A49 lay-by the public footpath ascends an open grassland field
underlain by Wenlock Shales. The map of Ref. 1 is in error here since it
shows Lower Ludlow Shales. Above is a steeper slope carrying a heavy tree
cover and known as Hough’s Coppice. As the footpath enters this woodland a
drainage ditch contains examples of well rounded cobbles of fluvioglacial
material which occurs on the sides of the Church Stretton Valley at this
elevation. The footpath climbs through the coppice at a slant; in a
vertical direction the woodland is 55 m wide but the footpath takes 135 m to
reach the gate at the uppermost edge. From the lower entrance at the change
of slope there is a rock exposure on the right-hand side but it is 40 m to
the first clear exposure. Here a section one m high shows a compact
sequence of poorly bedded grey calcareous shales up to 100 mm thick with
harder irregular flaggy muddy grey limestone bands from 50 to 80 mm thick.
This lithology is characteristic of Tickwood Beds (which occur as a horizon
immediately below the Wenlock Limestone itself). Dip here was measured as
30 degrees to a 120 azimuth (SE). The strike direction cuts across the
flanks of the hillside only a little steeper than the line of the footpath.
As a result only a relatively thin section of beds is thereby exposed. In a
further 20 m a second exposure shows the harder beds much thicker (up to 60
mm) and of a more massive nature. Thin shales are exposed under the roots
of an adjacent tree. It is a further 70 m to the upper gate and the
limestone is now slightly more nodular but very short of the usual nodular
character found in the Wenlock Limestone proper. Beyond the gate are again
open fields with slope angles reverting to those of the lower field but
underlain by Lower Ludlow Shales (Eltonian). A stream defines the left-hand
side of these fields but has provided no useful exposure; it is dominated by
Uriconian rhyolites etc. derived from Caer Caradoc. The BGS sheet (Ref 1)
shows an outcrop width of 200 m and places the upper boundary of the Wenlock
Limestone outcrop well up these fields where it is succeeded again by
Wenlock Shales. There is nothing to suggest the presence of the actual
Wenlock Limestone here. |
2 km north of the traffic lights on the A49 at Church Stretton is a lay-by
on the right-hand (east) side. From here a signed footpath crosses the
field towards woodland with Caer Caradoc clearly visible above. |
RIGS Yes. Designation proposed as the largest and most accessible outcrop of
Wenlock Limestone “shelf” facies in close proximity to and immediately west
of the F1 component of the Church Stretton Fault |
Structure and Sedimentology/Stratigraphy |
|
1397 |
SO 354 952 |
Ridge (SW) |
Quarry (active) |
Precambrian; Wentnor Group; Bayston-Oakswood Formation (Ref. 1) |
Shallow re-entrant on western flank of elevated Precambrian landscape of
Norbury and Linley hills. Overlooks to the NW the deep valley of the
Pontesford-Linley fault separating the Precambrian from the Ordovician
Stiperstones. |
This new quarry in the purple sandstones of the Bayston-Oakswood Formation
would appear to offer the best evidence for strata inversion (see survey
report for Nurton SO 353 936). The quarry section is semicircular in
section with a diameter of some 15 m. It lies on the crest of a low ridge
and the height of the face varies from about 4 m in the centre to zero at
the extremities. Dips are constant and consistent at around 20 degrees to
the west. The quarry presents some 5 to 6 beds of massive flat jointed
purple sandstone up to one metre thick. These are separated by beds of dark
purple friable material which varies from sandstone with same grain size as
the massive beds through finer sandstone to distinct mudstone (at the right
hand end). Such a lithology offers a number of indicators for inversion.
Specifically these include: (1) a detectable grading in the thinner
sandstones but a grading in both senses (up and down); (2) possible
incipient load casts on the upper surface of the massive sandstones but
unconvincing since this may be associated with the jointing - the “casts”
form as shallow convex surfaces on the top surface between the orthogonal
joint planes; (3) pick-up clasts of purple mudstone are seen near the base
of some sandstones but equally such clasts can occur near the top; (4)
cross-bedding would seem likely in these coarse grain sediments but no
evidence was found by the surveyor. |
Easiest approach is from the hamlet of Cold Harbour (signposted from the
B4383 1.5 km south of Bridges). Take the minor road south towards Linley
and the quarry will be seen on the hillside above the first cattle grid
(where parking can be had); distance about 2 km. Alternatively take this
same minor road north from Linley where it is signposted to Cold Harbour.
The cattle grid is the second one, distance about 3 km. |
RIGS Yes. Designation proposed as a somewhat unusual
sandstone/siltstone/mudstone sequence and the best candidate for
demonstrating inversion of the B-O Formation. |
Sedimentology/Stratigraphy |
|
1398 |
SO 331 971 |
Mucklewick Hill Summit |
Natural exposure |
Ordovician; Llandeilo; Hope Shale Formation; Hyssington Volcanic Member
(Ref. 1) |
Highest point among ridges of hard volcanic rocks |
The local rocks are those of the Hyssington Volcanics which are interbedded
within the Hope Shales and have a strong sedimentary character. This can be
seen on the east flank of the hill where a steeply dipping bedding surface
is exposed comprising grey volcaniclastics that also comprise the abundant
talus that surrounds the summit (372 m AOD). However these are better
examined elsewhere and it is the view that is the principal feature and can
be summarized in three parts: (1) The most immediate feature is the ridge
from Grit Hill to the NE some 3 km to the SW. Like other examples within
the Shelve Inlier such hard rock ridges often show the offsets caused by
transverse (SE to NE) normal faults. (2) At the next level is the local
topography which is dominated by the two zones of lower ground of Hope
Shales. To the SE is the axis of the Llan Syncline between here and the tree
covered high ground of Brooks Hill (itself essentially the same Hyssington
Volcanics as Mucklewick). To the west is the complementary Shelve Anticline
with an axis between here and the dominant Corndon Hill. To the right (NW)
can be seen the ridge of Stapeley Hill (itself a second volcanic sequence
with the Hope Shales higher up the sequence than the Hyssington Volcanics
and of a much more basic character). (3) Finally on a wider 360 degree
panorama is the consequence of hard and soft rock sequence within the
regional geology. To the NNE is the high point of Myton Dingle and the
quartzite tors of the Stiperstones ridge extending south to a termination on
Black Rhadley Hill. Again to the south and going behind Corndon Hill are 5
hills in a line shaped in terms of scarp and dip by their underlying
sediments and volcanics. North of Corndon is the Stapeley Ridge continuing
round to high ground occupied by the Silurian of Venus Bank and then finally
the distinct marker of the tree cluster of Bromlow Callow. |
Mucklewick Hill can be approached by numerous walking routes using the
network of local paths. These intersect the road network at places such as:
Shelve; The Bog; Nind; and the Grit mines on the A488. |
RIGS Yes. Designation proposed a splendid panorama of the local geological
structure and stratigraphy |
Structure and Sedimentology/Stratigraphy |
|
1399 |
SO 328 966 |
Mucklewick Hill (SW) |
Quarry (active) |
Ordovician; Llandeilo; Hope Shale Formation; Hyssington Volcanic Member
(Ref. 1) |
Quarry is situated on the SE facing flank of a NE trending ridge of volcanic
rocks |
To quote from the BGS Memoir for the Montgomery Sheet “the Hyssington
Volcanics are made up of principally acid vitroclastic crystal and lithic
tuffs, laminated tuffites and associated volcaniclastic sedimentary rocks
interbedded with the mudstones of the Hope Shales” (Ref. 2 page 19). The
single main face of the quarry is some 40 m long and up to 6 m high and
presents bedding planes which dip 45 degrees to the SE. These planes are
mainly of the Hope Shales of dark grey mudstone variously blocky or
fissile. The shales are interbedded with a variety of volcanics the
extraction of which is the purpose of the quarry. At either end of the main
face are dip sections which show the interbedding in terms of the thickness
of the individual units. There is a marked difference between these two
sections which suggests that the quarry face is not exactly cut along the
strike. The quarry contains abundant talus examination of which quickly
confirms the wide range of rock types represented in the Hyssington
Volcanics. The Hope Shales show some variations. Some examples show a
hardening of the original mudstone giving a more fissile character that
suggests some localized heating. There are also some good examples of the
concentric diffusion patterns (Leisegang rings (?)) implying processes
whereby components of the volcanics have interpenetrated the shales. There
is a host of different volcanic rock types ranging in terms of particle size
from finely laminated to heterogeneous grits with differences of hardness
colour and so on. The dip section at the right hand end of the quarry (NE)
is roughly 8 m wide and shows within that distance at least 8 bands of shale
(none thicker than 200 mm). The interbedded volcanics vary in thickness by
a factor of 100 (from 50 mm to 5 m). Contacts with underlying shales are
sharp with slight load casting and shale distortion evident. This section
provides an excellent opportunity for a very detailed examination;
stratigraphic logging would be appropriate. The section at the left hand
end is in sharp contrast. Some 10 m wide it is of massive grey
crystallinity with some fining upwards but impressing mainly with the
perfectly flat orthogonal joint faces. Its sedimentary nature is deduced
from the base which rests on the bedding plane of underlying shales with an
additional thin (<10 mm) shale horizon some 100 mm above the base. The
crest of the ridge above the quarry shows numerous natural outcrops aligned
in a NE direction but then is abruptly terminated. From the BGS map of Ref.
1 it appears that a transverse fault down-throwing to the north has offset
the outcrop to the left (NW) where it continues as a less conspicuous
feature. A strong ridge now appears to the right (SW) representing a
different “unit” within the Hyssington Volcanics. |
The area of Mucklewick Hill is well endowed with footpaths. By vehicle from
the A488 take the turn east signposted to Nind. After 1 km turn left at the
T-junction signed as a no through road. A lay-by will be encountered on the
right-hand side opposite the second of two sets of farm buildings. Continue
by walking further along the lane and take the first track branching to the
left. This leads directly to the quarry which shortly becomes visible.
Note the numerous examples of volcanics which occur in the track surface.
Alternatives are directly by footpath from the point at SO 324 961 on the
A488 distance 0.5 km or by footpaths from Shelve via Grit Hill and Shelve
Pool; distance about 2 km. |
RIGS Yes. Designation proposed as a splendid demonstration of the Hyssington
Volcanics - acid vitroclastic crystal and lithic tuffs; laminated tuffites
and associated volcaniclastic sedimentary rocks interbedded with the
mudstones of the Hope Shales |
Sedimentology/Stratigraphy |
|
1400 |
SO 449 943 |
Cardingmill Valley (Church Stretton) |
Quarry (disused) |
Precambrian; Longmyndian; Burway Formation |
Situated near exit from Cardingmill Valley; one of a number of steep sided
non-glaciated “batches” which drain the SE flank of the Longmynd |
It was Susan Beale (previously Secretary of the SGS) who first observed a
number of thin orange seams lying along the bedding planes of this quarry.
She considered them to be the result of contemporaneous ash falls but
(whilst they may be of volcanic origin) an ash fall has not been confirmed
by subsequent observations. The quarry on the NE side of the valley was
excavated in the turbidite sequence of the Burway Formation – previously
known as the Burway Flags. It presents a face of about 5 m height aligned
roughly in the dip plane and at right angles to the strike. Younging
direction is from right to left. Some six orange seams are clearly visible
each one lying upon the planar shale component of the turbidite units and
overlain by the similar planar basal fine sandstone or siltstone unit. The
seams were therefore deposited in the intervals between turbidite flows.
The seams are typically of thickness between 10 and 30 mm. Spacing between
the seams is irregular. From right to left in the younging direction:
Thickness/Spacing: 20-30 mm / 1.16 m; 15 mm / 0.28 m; 10 mm / 4.17 m; 10 mm
/ 0.52 m; 2 of ca. 10 mm / 0.61 m; 10 mm / 1.22 m; ca. 10 mm. The discovery
of around 5 similar seams in the Batch Valley at approximately the same
horizon (some 100 m above the base of the Burway Formation turbidites)
prompted a search to establish their lateral extent. Going south they have
been found also in similar numbers: in Cwmdale on Novers Hill; in Townbrook
Hollow as two seams; and in Ashes Hollow as one seam. They have not been
found north or south of these two limits. Separation distances between the
individual bands differ so much at each of the above places as to prevent
any correlation. What all the seams have in common are sedimentological
effects. The seams have a lamination which resembles that in certain
mudstones such as that of the Stretton Shales. A thin section indicates a
clay mineral composition with some amounts of secondary quartz
mineralisation. Bases of the seams can be perfectly flat but more usually
show undulations which vary from fine to unequivocal load casts simply
indicating the degree of diagenetic hardening of the underlying turbidite
shale when the seam was emplaced. Traced upwards the seams show a
gradational texture involving an often present purple band 1 to 2 mm thick
succeeded by fine laminations showing that the full thickness of the seam is
greater than that of the orange colouration In at least two cases it has
been noticed that this full seam can suffer slumping producing short
wavelength folds of up to 10 mm amplitude. |
Cardingmill Valley is signposted from Church Stretton and the quarry is on
the right-hand side 50 m past the first cattle grid |
RIGS Yes. Designation proposed as the type section of ?volcanic seams
deposited in the intervals between turbidite flows |
Sedimentology/Stratigraphy |
|
1401 |
SO 257 888 |
Dolfawr (Lower & Middle) |
Quarry (disused) |
Silurian; Ludlow Series; Bailey Hill Formation (Ref. 1) |
Exposures lie mainly on valley sides of the River Unk immediately downstream
of a river capture which changes its course from SE to NW and from along
strike to across strike. |
The identifying grid reference SOI251887 is placed adjacent to Lower Dolfawr
Farm. Exposures are alongside public footpaths and show some degree of
disturbance as folding and thrusting which are presumed to arise from
compressive forces (stress) associated with the Clun Forest Disturbance –
see Woodcock (1984). It is the view of the surveyor that the exposures
(1401-1407) are illustrative of this effect and all link together as a
single unit – albeit of appreciable scale; the most separated exposures are
1.25 km apart. As such they warrant some particular examination going well
beyond what can be presented in this report; here the concern is only with
the location and outline description of each exposure. SO 257 888 extends
westwards from a gateway down the slope of a track. At the start is a
continuous section 2 m high of undisturbed Bailey Hill Beds showing shallow
dip and the characteristic fine sandstone and siltstone couplets. The
distinguishing graptolite Saetograptus was found here. After 20 m of
exposure these beds suddenly abut against highly disturbed strata of the
same Bailey Hill Formation with near vertical dip at 80 degrees west. The
zone of demarcation appears to be a fault although it has produced very
little in the way of drag effects. The near vertical strata then continue
westwards for 20 m. The main variations are dip angles sometimes down to 60
degrees and some bending of the strata. Observation of grading and slight
load casting of the sandstone units suggests the whole width of this outcrop
youngs to the west. |
Access to Dolfawr is by public footpaths of which there are various
options. The most dramatic is that following the River Unk from the near
the plantation as point 475 near which there is abundant parking. Other
routes are: south from Pantglas (some parking); NW from Edenhope (verge
parking only); and east from Upper Edenhope. |
RIGS Yes. Designation proposed as these are textbook quality exposures of
folding and thrusts belonging to the Clun Forest Disturbance |
Structure and Sedimentology/Stratigraphy |
|
1402 |
SO 247 887 |
Dolfawr (Lower & Middle) |
Quarry (disused) |
Silurian; Ludlow Series; Bailey Hill Formation (Ref. 1) |
Exposures lie mainly on valley sides of the River Unk immediately downstream
of a river capture which changes its course from SE to NW and from along
strike to across strike. |
The identifying grid reference SOI251887 is placed adjacent to Lower Dolfawr
Farm. Exposures are alongside public footpaths and show some degree of
disturbance as folding and thrusting which are presumed to arise from
compressive forces (stress) associated with the Clun Forest Disturbance –
see Woodcock (1984). It is the view of the surveyor that the exposures
(1401-1407) are illustrative of this effect and all link together as a
single unit – albeit of appreciable scale; the most separated exposures are
1.25 km apart. As such they warrant some particular examination going well
beyond what can be presented in this report; here the concern is only with
the location and outline description of each exposure. SO 247 887 shows a
section of length 100 m which extends from a gate south-eastwards down the
track. It is dominated by near vertical strata with some local curvature
suggesting involvement of folding. The section also includes an old quarry
which (like all the trackside exposures) has come about as a result of the
local farmer(s) excavating the side bank for hardcore. |
Access to Dolfawr is by public footpaths of which there are various
options. The most dramatic is that following the River Unk from the near
the plantation as point 475 near which there is abundant parking. Other
routes are: south from Pantglas (some parking); NW from Edenhope (verge
parking only); and east from Upper Edenhope. |
RIGS Yes. Designation proposed as these are textbook quality exposures of
folding and thrusts belonging to the Clun Forest Disturbance |
Structure and Sedimentology/Stratigraphy |
|
1403 |
SO 250 886 |
Dolfawr (Lower & Middle) |
Quarry (disused) |
Silurian; Ludlow Series; Bailey Hill Formation (Ref. 1) |
Exposures lie mainly on valley sides of the River Unk immediately downstream
of a river capture which changes its course from SE to NW and from along
strike to across strike. |
The identifying grid reference SOI251887 is placed adjacent to Lower Dolfawr
Farm. Exposures are alongside public footpaths and show some degree of
disturbance as folding and thrusting which are presumed to arise from
compressive forces (stress) associated with the Clun Forest Disturbance –
see Woodcock (1984). It is the view of the surveyor that the exposures
(1401-1407) are illustrative of this effect and all link together as a
single unit – albeit of appreciable scale; the most separated exposures are
1.25 km apart. As such they warrant some particular examination going well
beyond what can be presented in this report; here the concern is only with
the location and outline description of each exposure. SO 250 886 is another
long exposure which mixes elements of verticality folding and thrusting in
quite a dramatic manner. The strata retain a recognizable Bailey Hill beds
texture of sandstone/siltstone couplets. |
Access to Dolfawr is by public footpaths of which there are various
options. The most dramatic is that following the River Unk from the near
the plantation as point 475 near which there is abundant parking. Other
routes are: south from Pantglas (some parking); NW from Edenhope (verge
parking only); and east from Upper Edenhope. |
RIGS Yes. Designation proposed as these are textbook quality exposures of
folding and thrusts belonging to the Clun Forest Disturbance |
Structure and Sedimentology/Stratigraphy |
|
1404 |
SO 245 885 |
Dolfawr (Lower & Middle) |
Quarry (disused) |
Silurian; Ludlow Series; Bailey Hill Formation (Ref. 1) |
Exposures lie mainly on valley sides of the River Unk immediately downstream
of a river capture which changes its course from SE to NW and from along
strike to across strike. |
The identifying grid reference SOI251887 is placed adjacent to Lower Dolfawr
Farm. Exposures are alongside public footpaths and show some degree of
disturbance as folding and thrusting which are presumed to arise from
compressive forces (stress) associated with the Clun Forest Disturbance –
see Woodcock (1984). It is the view of the surveyor that the exposures
(1401-1407) are illustrative of this effect and all link together as a
single unit – albeit of appreciable scale; the most separated exposures are
1.25 km apart. As such they warrant some particular examination going well
beyond what can be presented in this report; here the concern is only with
the location and outline description of each exposure. SO 245 885 is the
exemplar of the set. It is an unusual excavation of the two outer sides of
a small hillock or ridge giving two outward faces at 90 degrees to each
other and each some 20 to 25 m long and up to 4 m high. The westward face
shows a range of exquisite folds which can be seen to develop from fairly
low dip ground to the left. At the right these folds merge into unequivocal
thrusting and around the corner on the south face are the edges of the
thrusted beds all dipping inward at about 30 degrees. |
Access to Dolfawr is by public footpaths of which there are various
options. The most dramatic is that following the River Unk from the near
the plantation as point 475 near which there is abundant parking. Other
routes are: south from Pantglas (some parking); NW from Edenhope (verge
parking only); and east from Upper Edenhope. |
RIGS Yes. Designation proposed as these are textbook quality exposures of
folding and thrusts belonging to the Clun Forest Disturbance |
Structure and Sedimentology/Stratigraphy |
|
1405 |
SO 243 881 |
Dolfawr (Lower & Middle) |
Quarry (disused) |
Silurian; Ludlow Series; Bailey Hill Formation (Ref. 1) |
Exposures lie mainly on valley sides of the River Unk immediately downstream
of a river capture which changes its course from SE to NW and from along
strike to across strike. |
The identifying grid reference SOI251887 is placed adjacent to Lower Dolfawr
Farm. Exposures are alongside public footpaths and show some degree of
disturbance as folding and thrusting which are presumed to arise from
compressive forces (stress) associated with the Clun Forest Disturbance –
see Woodcock (1984). It is the view of the surveyor that the exposures
(1401-1407) are illustrative of this effect and all link together as a
single unit – albeit of appreciable scale; the most separated exposures are
1.25 km apart. As such they warrant some particular examination going well
beyond what can be presented in this report; here the concern is only with
the location and outline description of each exposure. At SO 243 881 the
river meanders have cut into the steep south bank causing slippage of soil
and revealing bedrock as a slightly curved steeply dipping face with an
indeterminate discontinuity higher up. It is considered here that this
locality lies at the edge of the general disturbance since no other aberrant
exposure have been found upstream of here. |
Access to Dolfawr is by public footpaths of which there are various
options. The most dramatic is that following the River Unk from the near
the plantation as point 475 near which there is abundant parking. Other
routes are: south from Pantglas (some parking); NW from Edenhope (verge
parking only); and east from Upper Edenhope. |
RIGS Yes. Designation proposed as these are textbook quality exposures of
folding and thrusts belonging to the Clun Forest Disturbance |
Structure and Sedimentology/Stratigraphy |
|
1408 |
SJ 489 125 |
The "Bell-stone" in the precincts of the Morris Hall Bellstone Shrewsbury
SY1 1JB |
Erratic |
Quaternary; Devensian |
Glacial erratic of irregular shape 3 feet long and 2 feet wide and about 1
foot thick weighing probably not less than one-third of a ton; has been
moved several times within central Shrewsbury. |
A notable boulder said in Darwin's autobiography to have probably marked a
boundary and known as the "Bell-stone". Darwin tells us that while he was at
Shrewsbury School at the age of 13 or 14 "an old Mr Cotton
[this was the Shropshire naturalist Richard Cotton who
died in 1839] in Shropshire who knew a good deal
about rocks" pointed out to me "...the 'bell-stone'; he told me that there
was no rock of the same kind nearer than Cumberland or Scotland and he
solemnly assured me that the world would come to an end before anyone would
be able to explain how this stone came where it now lay"! Darwin adds "This
produced a deep impression on me and I meditated over this wonderful
stone.". Astonishingly high powered discussion and examination of the
Bell-stone on Darwin's centenary (1909) by Bonney Watts Harker and
Fearnsides in Judd's account of the volume edited by Seward; all six were
FGS and were or became Professors and FRS! Concluded that this was a glacial
erratic (as realised by Darwin in later life); the rock itself is a much
altered andesite and was probably derived from the Arenig district in North
Wales or possibly from a point nearer the Welsh Border by glacial action -
it is NOT a 'granite' as stated by the plaque (2008)! |
Permitted access through courtyard of the Morris Hall. |
RIGS Yes. Historically important site in connection with early influences on
Charles Darwin. |
Mineralogy/Petrology |
|
1409 |
SJ 715 417 |
Dorrington Lane nr Woore |
View |
Quaternary; Devensian |
Hummocky moraine thought to coincide with limit of glacial re-advance in
Late Devensian. |
No permanent exposures of glacial sediments but clear manifestation of
hummocky terrain including superimposed hummocks; detailed web panorama of
temporary exposure at Woore Hall Farm [SJ 721 423] at www.gigapan.org/viewGigapan.php?id=4458.
Pronounced proximal slope terrain to north and east with relief up to 15 m [SJ
715 417]; gentler distal slope terrain to south and west [SJ 723 415]. Part
of the "Wrexham-Ellesmere-Wem-Whitchurch-Woore" moraine of Clark's Glacial
Map of Britain (2004). |
Public bridleway at end of Dorrington Lane. |
RIGS Yes. A prominent and characteristic landscape for the extreme northeast
of Shropshire. |
Geomorphology/Landscape |
|
1410 |
SJ 603 086 |
Rushton |
Track/roadside |
Precambrian: Rushton Schists. Special Sheet 60 - Telford. |
Exposed in track bed at top of rise on to low hill (possibly downstream edge
of glacial roche moutonée)
400 m NW of Rushton village. |
Exposures of the Rushton Schists are rare and this one is revealed by
vehicle erosion across a trackway. Exposed are thinly laminated
fine-grained dark grey foliated schists with visible quartz plagioclase and
mica; possibly garnet too. Distinct lenses of coarsely crystalline pink
quartz feldspar gneissose rock giving a migmatitic expression. Foliation
very steep inclined; striking approx N-S. Thought to have originally been
subducted mudstones subsequently regionally metamorphosed to a medium/high
grade ca. 670Ma. |
Public bridleway between Rushton and Uppington. |
RIGS Yes. Although a 2D exposure (in trackbed) it is one of very few easily
accessible Rushton Schists exposures. The site is easily accessible and
exposes the oldest rocks of Shropshire. |
Mineralogy/Petrology |
