The BGS Lexicon of Named Rock Units — Result Details

Seascale Glacigenic Formation

Computer Code: SEAG Preferred Map Code: SEA
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Interbedded sand, gravel, silt, clay, pebbly clay diamicton and gravelly sandy clay diamicton, typically reddish brown, containing clasts mostly derived from the northwestern valleys of the Lake District (granophyre, red sandstone, greywacke, welded tuff), the West Cumbrian Coalfield (yellow and white sandstone, coal), but with some from Scotland (greywacke, granodiorite).
Definition of Lower Boundary: Generally a sharp, irregular, unconformable contact with bedrock, or locally a sharp, undulating, unconformable contact with stony clay diamicton of the Holmrook Till Member of the Blengdale Glacigenic Formation.
Definition of Upper Boundary: Variable, but commonly the ground surface or a sharp, planar, unconformable contact with reddish brown pebbly sandy clay diamicton units of the Gosforth Glacigenic Formation.
Thickness: To 20m
Geographical Limits: West Cumbrian coast to the west of the Lake District and west of the limit of the 'Gosforth Oscillation' between Cleator and Ravenglass.
Parent Unit: Irish Sea Coast Glacigenic Subgroup (ISCG)
Previous Name(s): Middle Sands and Gravels [Obsolete Name and Code: Use GFSA, SEAG, CGWD, LOGG, PLSG, PFS, EVSI, THBG, EVSG] (-122)
Lower Boulder Clay [Obsolete Name and Code: Use CHAK, STIL, SEAG, RVTI, LWTI, STPTG] (-2079)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Sea cliff section 500m south of Ravenglass, Cumbria (exposing Ravenglass Till Member only) Nirex, 1997. 
Partial Type Section  Sea cliffs at St Bees, Cumbria (exposing Lowca Till, St Bees Silt, St Bees Sand and Gravel members only). Nirex, 1997. 
Reference(s):
Merritt, J W and Auton, C A. 1997. Quaternary lithostratigraphy of the Sellafield district. Nirex Science Report SA/97/045 (Issue 2.0). [Report prepared for UK Nirex Ltd. 69pp, 5 tables, 20 figures, 14 enclosures and one appendix.] 
Akhurst, M C, Chadwick, R A, Holliday, D W, McCormac, M, McMillan, A A, Millward, D, Young, B, Ambrose, K, Auton, C A, Barclay, W J, Barnes, R P, Beddoe-Stephens, B, James, J C W, Johnson, H, Jones, N S, Glover, B W, Hawkins, M P, Kimbell, G S, MacPherson, K A T, Merritt, J W, Milodowski, A E, Riley, N J, Robins, N S, Stone, P, and Wingfield, R T R. 1997. The geology of the west Cumbria district. Memoir of the British Geological Survey, Sheets 28, 37 and 47 (England and Wales). 138pp. 
Trotter, F M, Hollingworth, S E, Eastwood T and Rose, W C C. 1937. Gosforth District. Geological Survey Memoir, England and Wales, Sheet 37. 
Huddart, D. 1991. The glacial history and glacial deposits of the north and west Cumbrian lowlands, 151-167 in Ehlers, J, Gibbard, P L and Rose, J (editors), Glacial deposits in Great Britain and Ireland. [London: Balkema.] 
Eastwood T, and others. 1968. Geology of the country around Whitehaven. Memoir of the Geological Survey of Great Britain, Sheet 28 (England and Wales). 
Merrit, J W and Auton, C A. 2000. An outline of the lithostratigraphy and depositional history of Quaternary deposits in the Sellafield district, west Cumbria. Proceedings of the Yorkshire Geological Society, Vol.53, 129-154 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable