The BGS Lexicon of Named Rock Units — Result Details

Keisley Limestone Formation

Computer Code: KYL Preferred Map Code: KyL
Status Code: Full
Age range: Ashgill Series (OA) — Ashgill Series (OA)
Lithological Description: Dark grey nodular limestone with siltstone partings overlain by grey massive beds of bioclastic limestone that are locally dolomitised; probably lowest part seen comprises dark grey siltstone with thin impure limestone beds. Thin unit of synsedimentary breccia and siltstone at top of Formation. Limestone is locally richly fossiliferous.
Definition of Lower Boundary: Formation seen only in core of anticline, base not reached.
Definition of Upper Boundary: Taken at the base of black mudstones of overlying Silurian strata.
Thickness: More than 50m
Geographical Limits: Only seen in the Keisley area, Cross Fell Inlier, Cumbria.
Parent Unit: Dent Group (DNT)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Keisley Quarry, about 300m east of Keisley, Cumbria Owen and Rushton, 1999 
Reference(s):
Owen, A W and Rushton, A W A, 1999. Arenig to Ashgill of northern England. pp 259-292 in Rushton, A W A, Owen, A W, Owens, R M, and Prigmore, J K. British Cambrian to Ordovician stratigraphy. Geological Conservation Review, Vol. 18. Joint Nature Conservation Committee. Peterborough. 
Burgess, I C and Holliday, D W. 1979. Geology of the country around Brough-under-Stainmore. Memoir for 1:50 000 geological sheet 31 and parts of sheets 25 and 30. Geological Survey of Great Britain (England and Wales). [London: HMSO.] 131pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E031