The BGS Lexicon of Named Rock Units — Result Details

Lodge Farm Limestones Bed

Computer Code: LGFL Preferred Map Code: LFL
Status Code: Full
Age range: Sinemurian Age (JS) — Sinemurian Age (JS)
Lithological Description: Group of several thin (six of 0.04 to 0.14m thick in type section) probably impersistent limestone beds separated by mudstone beds (up to 0.3m thick). Limestones are hard, grey, brown-weathering, silty, bioclastic, fine- to medium-grained, with numerous bored Gryphaea and Pseudopecten. auna also includes gastropods, other bivalves, ostracods and echinoderms. Forms a weak feature.
Definition of Lower Boundary: Change up from grey mudstone with phosphatic nodules of the undifferentiated Foston Member; at 30.90m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Definition of Upper Boundary: Change up from grey mudstone of the undifferentiated Foston Member; at 29.51m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Thickness: 1.0 to 3.5m; 1.39m in type section.
Geographical Limits: East Midlands: north Leicestershire to Lincolnshire. Not recognized in the Scunthorpe Mudstone Formation of north Lincolnshire, or south Leicestershire, where it passes south either into part of the more argillaceous Rugby Limestone Member of the Blue Lias Formation or into part of the mudstone-dominated Charmouth Mudstone Formation.
Parent Unit: Foston Member (FSTL)
Previous Name(s): Plungar Ironstone (-361)
Lodge Farm Limestone (-4160)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Fulbeck Airfield Borehole F/B5 (SK95SW/17). 
Reference(s):
Berridge, N G, Pattison, J, Samuel, M D A, Brandon, A, Howard, A S, Pharaoh, T C and Riley, N J. 1999. Geology of the Grantham district. Memoir of the British Geological Survey, sheet 127 (England and Wales). 
Sylvester-Bradley, P C and Ford, T D (editors), 1968. The Geology of the East Midlands. (Leicester: Leicester University Press.) 
Brandon, A, Sumbler, M G and Ivimey-Cook, H C, 1990. A revised lithostratigraphy for the Lower and Middle Lias (Lower Jurassic) east of Nottingham, England. Proceedings of the Yorkshire Geological Society, Vol.48, 121-141. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E126 E127 E142