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BUXTON QUARRY
FILE REFERENCE: SO459955.
Grid
reference: SO459955.
LOCALITY: Buxton Quarry, All
Stretton.
PARISH: All Stretton.
STATUS: RIGS entered 21/09/98.
Surveyor: Martin Allbutt. Date of survey: 18/03/1998.
Previous
reports:
FEATURE: Quarry (disused).
STRATIGRAPHY: Pre-Cambrian; Stretton Series; Stretton Shale Group; Buxton Rock. Burway Group. TYPE LOCALITY:
Buxton Rock.
GEOMORPHOLOGY:
DESCRIPTION: 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
appearence, has been used to define the base of a more arenaceous and flaggy
Burway Group over lower and generally incompetent Stretton Shales. This
Buxton Quarry provides the type section. The RHS is dominated by a
vertical bedding plane is Stretton Shales, a rock of weakly bedded
and monontonous grey mudstone/fine siltstone. Occassisonal paler bands up to 1 cm. thick
may mark the presence of volcanic ash
fall-outs. The main outcrop of Buxton rock is in the centre when 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 tosplit by shaly horizons into seperate units of variable thickness
and at least 8 such beds between 20 and
50 cms 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
5 to 15 cms 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 metres across long base, 20 metres across short
and up to 25 metres 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.
ACCESS: In All Stretton take
lane sign posted to 'Village Hall'; Quarry is on right after 200metres. Ample
parking and shop/pub/hotel in All Stretton.
DESIGNATION:
Assessment:
Education: 0
Scientific: 0
Historic: 0
Aesthetic: 0
RIGS: Buxton Quarry should be designated a RIGS as the type section for the Buxton Rock, which is a marker horizon for the boundary between lithologically changing rocks of the Stretton Shale Group and the Burway Group within the Pre-Cambrian.
LIGS:
CONSERVATION: May be within Longmynd SSSI. Exposure clear.
Priority:
OWNER/OCCUPIER: National Trust.
References: 1)Regional Handbook for Welsh Borderland (1971) p.22 .
2)Geology Ch. Stretton Area; Memoir
to sheet 166; (1968) p.78 .
3)A-level Field Guide; John
Moseley; Geol. To-day; March 1992.
4) E.S.Cobbold; in 'Church
Stretton'; (1900).
Cross-reference(s): Quarries at Cardingmill Valley SO449943 and Ashes Hollow Valley plane and similar
outcrops are found in a lane just to the west SO441920.
Addenda: POTENTIAL USE: Itinerary, demonstration of vertical strata and younging direction, subtle changes in a bedded sequence, a mappable horizon.