The BGS Lexicon of Named Rock Units — Result Details

Fenton Limestone Bed

Computer Code: FNTL Preferred Map Code: Fn
Status Code: Full
Age range: Sinemurian Age (JS) — Sinemurian Age (JS)
Lithological Description: Hard, olive grey, brown weathering, finely sandy (especially in the north), silty, bioclastic, fine-grained limestone, in one or locally two beds, with small ammonites and pectiniids. Fauna also includes forams, serpulids, brachiopods, other bivalves, ostracods and echinoderms. Forms a weak feature.
Definition of Lower Boundary: Change up from grey mudstone of undifferentiated Foston Member; at 27.10m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Definition of Upper Boundary: Change up into grey mudstone of undifferentiated Foston Member; at 26.76m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Thickness: 0.3 to 1.0m; 0.34m in type section
Geographical Limits: East Midlands; north Leicestershire to Lincolnshire. Not recognised in the Scunthorpe Mudstone Formation of north Lincolnshire, or south Leicestershire, where it passes south into either part of the more argillaceous Rugby Limestone Member of the Blue Lias Formation or part of the mudstone dominated Charmouth Mudstone Formation.
Parent Unit: Foston Member (FSTL)
Previous Name(s): Fenton Limestone (-1544)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Fulbeck Airfield Borehole F/B5 (SK95SW/17). 
Reference(s):
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. 
Carney, J N, Ambrose. K and Brandon A, 2002. Geology of the Melton Mowbray district - a brief explanation of the geological map. British Geological Survey Sheet Explanation, Sheet 142 (England and Wales). 
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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E127 E142 E126