The BGS Lexicon of Named Rock Units — Result Details

Kirk Stile Formation

Computer Code: KST Preferred Map Code: KSt
Status Code: Full
Age range: Arenig Series (OR) — Llanvirn Series (OE)
Lithological Description: Thinly laminated to very thinly bedded dark grey siltstones and mudstones, local lenticular units of ithic wacke; underlain by greywackes of the Loweswater Fromation; overlain by the volcaniclastic Eycott Volcanic Group.
Definition of Lower Boundary: Taken above the uppermost thin sandstone of the underlying Loweswater Formation on Whiteside End.
Definition of Upper Boundary: Taken as the youngest beds beneath volcaniclastic rocks of the Eycott Volcanic Group.
Thickness: 1500 to 2500m
Geographical Limits: The Kirk Stile Formation crops out north of the Causey Pike Fault within the Skiddaw inlier. The fault forms the southern boundary of the Formation. Elsewhere it is unconformably overlain by rocks of the Eycott Volcanic Group or Carboniferous limestones.
Parent Unit: Skiddaw Group (SKG)
Previous Name(s): Kirk Stile Slates (-1633)
Blakefell "Mudstone" (-4138)
Mosser Slates (-352)
Mosser-Kirkstile Slates (-353)
Sunderland Slates (-1007)
Kirkstile Slates (-3504)
Black Slates Of Skiddaw (-4740)
Mosser Striped Slates (-4741)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Whinlatter Pass through Sleet How to Outerside. Cooper et al, 1995. 
Reference(s):
Rushton A W A. 1988. Tremadoc trilobites from the Skiddaw Group in the English Lake District. Palaeontology, Vol.31(3), 677-698. 
Cooper, D C, Lee, M K, Forty, N J, Cooper, A H, Rundle, C C, Webb, B C and Allen, P M. 1988. The Crummock Water Aureole: a zone of metasomatism and source of ore metals in the English Lake District. Journal of the Geological Society, Vol.145(4), 523-540. 
Jackson, D E. 1978. The Skiddaw Group. 79-98 in Moseley, F (Ed.), The Geology of the Lake District. Yorkshire Geological Society, Occasional Publication, No.3. 
Jackson, D E. 1961. Stratigraphy of the Skiddaw Group in Cumberland, England. Geological Magazine, Vol.98, 515-528. 
Simpson, A. 1967. The stratigraphy and tectonics of the Skiddaw Slates and the relationship of the overlying Borrowdale Volcanic Series in part of the Lake District, Geological Journal, Vol.5, 391-418. 
Rose, W C C. 1955. The sequence and structure of the Skiddaw Slates of the Lake District in the Keswick-Buttermere area. Proceedings of the Geological Association, Vol.65, 403-406 
Eastwood, T. 1933. In Summ. Prog. Geological Survey of Great Britain for 1932. Pt 1, p.59. 
Dixon, E E L. 1925. In Summ. Prog. Geological Survey of Great Britain for 1924, 70-71. 
Ward, J C. 1876. The geology of the northern part of the English Lake District. Memoir of the Geological Survery of Great Britain. 132. 
Cooper, A H, Rushton, A W A, Molyneux, S G, Hughes, R A, Moore, R M and Webb, B C. 1995. The stratigraphy,correlation, provenance and palaeogeography of the Skiddaw Group (Ordovician) in the English Lake District. Geological Magazine, Vol.132(2), 185-211. 
Webb, B C and Cooper, A H. 1988. Slump folds and gravity slide structures in a Lower Palaeozoic marginal basin sequence (the Skiddaw Group), NW England. Journal of Structural Geology, Vol.10(5), 463-472. 
Fortey, N J, 1989. Low grade metamorphism in the Lower Ordovician Skiddaw Group of the Lake District, England. Proceedings of the Yorkshire Geological Society, Vol.47(4), 325-337. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E029 E023 E028