The BGS Lexicon of Named Rock Units — Result Details

Greenscoe Tuff Formation

Computer Code: GCOE Preferred Map Code: GSC
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Interbedded sucession of silty mudstone, andesitic lapilli-tuff and tuff-breccia with andesite intrusions. The volcanic component increases up the succession.
Definition of Lower Boundary: Unconformity. Erosion surface cut in Skiddaw Group.
Definition of Upper Boundary: Unconformity. Overlain by clastic/carbonate succession of the Dent Group.
Thickness: none recorded or not applicable
Geographical Limits: East side of Duddon Estuary (Furness Inlier) between Green Haume (SD 221 751) and Soutergate (SD 227 813), Askam in Furness, Cumbria.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Mottled Shale (-4670)
Mottled Tuff (-276)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Greenscoe Quarry and Greenscoe Cragg south east of Askam in Furness, Cumbria. 
Reference(s):
Rose, W C C. 1977. Geology and Hematite deposits of South Cumbria. Economic Memoir for 1:50,000 Sheet 58 and southern part of Sheet 48. Memoir of the geological Survey of Great Britain. 
Green, J F N, 1913. The older Palaeozoic succession of the Dudden Estuary. London, 23pp. 
Johnson, E W, Soper, N J, Burgess, I C, Ball, D F, Beddoe-Stephens, B, Carruthers, R M, Fortey, N J, Hirons, S, Merritt, J W, Millward, D, Roberts, B, Walker, A B and Young, B. 2001. Geology of the country around Ulverston. Memoir of the British Geological Survey, England and Wales, Sheet 48. 
British Geological Survey, 1994. Askam SD27NW solid and drift 1:10,000 (Keyworth, Nottingham, British Geological Survey). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E048