The BGS Lexicon of Named Rock Units — Result Details

Buttermere Formation

Computer Code: BUF Preferred Map Code: BUF
Status Code: Full
Age range: Tremadoc Series (O1) — Arenig Series (OR)
Lithological Description: An olistrostrome deposit comprising disrupted, sheared and folded mudstone, siltstone and sandstone turbidite olistoliths. There are two members near the middle of the Formation, the Goats Gill Member, a sedimentary breccia and the sandstone-dominated Robinson Member.
Definition of Lower Boundary: Not exposed.
Definition of Upper Boundary: The upper boundary is tectonic and overthrust by rocks of the Crummock Water Aureole.
Thickness: 1500m+
Geographical Limits: It is bounded to the north and northwest by the Causey Pike Fault. To the south and southeast the formation extends to the overlying Borrowdale Volcanic Group unconformity. To the west the extent of the formation is unclear, exposures in the River Calder may be Buttermere Formation or a lower part of the succession.
Parent Unit: Skiddaw Group (SKG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Around High Snockrigg and Robinson. Cooper et al, 1995. 
Type Area  East of Buttermere village around Sail Beck. Water-polished slabs in Sail Beck. Cooper et al, 1995. 
Reference(s):
Webb, B C. 1990. The Buttermere Formation (Skiddaw Group) in the Robinson area. 74-82 in Moseley, F (Ed.), The Geology of the Lake District. [The Geologists' Association.] 
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. 
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. 
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. 
Jackson, D E. 1961. Stratigraphy of the Skiddaw Group in Cumberland, England. Geological Magazine, Vol.98, 515-528. 
Eastwood, T. 1933. In Summ. Prog. Geological Survey of Great Britain for 1932. Pt 1, p.59. 
Ward, J C. 1876. The geology of the northern part of the English Lake District. Memoir of the Geological Survery of Great Britain. 132. 
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 
Dixon, E E L. 1925. In Summ. Prog. Geological Survey of Great Britain for 1924, 70-71. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E029 E028