The BGS Lexicon of Named Rock Units — Result Details

Low Furness Basal Formation

Computer Code: LFSB Preferred Map Code: BB
Status Code: Full
Age range: Courceyan Substage (CF) — Chadian Substage (CI)
Lithological Description: Conglomerate, sandstones, siltstones and mudstones with subordinate evaporites, presumed of terrigenous origin in lower part (Duddon Conglomerates). Upper part of limestones and siltstones, mostly red with interbedded conglomerates; all presumed of marine origin.
Definition of Lower Boundary: Basal unconformity on pre-Carboniferous strata.
Definition of Upper Boundary: Base of overlying Martin Limestone.
Thickness: 0 to more than 200m
Geographical Limits: South Cumbria, Ulverston (48) and Barrow (58), 1:50k sheets.
Parent Unit: Not Applicable (-)
Previous Name(s): Basement Beds (-3812)
Alternative Name(s): none recorded or not applicable
Reference Section  Bore SD27NW/323, between rockhead at 46.56m and a presumed unconformable base upon LPZ strata at 255.50m. [The NGR in BGS records (below) falls on a wave-cut platform of Martin Limestone, whereas the hole records 46.56m of superficial deposits.] 
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. 
Dunham, K C and Rose, W C C. 1941. Geology of the iron-ore field of south Cumberland and Furness. Geological Survey of Great Britain, Wartime Pamphlet, No.16. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: