The BGS Lexicon of Named Rock Units — Result Details

Blackmires Limestone

Computer Code: BKML Preferred Map Code: Bm
Status Code: Full
Age range: Sinemurian Age (JS) — Sinemurian Age (JS)
Lithological Description: Limestone, bioclastic, shelly, grey, weathering brown, laterally persistent. Fauna includes echinoderms, serpulids, bivalves and corals. In type section Borehole F/B5, a single limestone bed was proved; elsewhere in the vicinity up to three similar, closely-spaced beds were proved, of which the highest is most persistent.
Definition of Lower Boundary: Change up from grey calcareous mudstone of undifferentiated Granby Member; 62.40m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Definition of Upper Boundary: Change up into grey calcareous mudstone of undifferentiated Granby Member; 62.10m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Thickness: 0.3m in type section; up to 2m in Leicestershire
Geographical Limits: East Midlands; north Leicestershire to Lincolnshire. Not recognised in north Lincolnshire, or south Leicestershire, where it may pass south into part of the Rugby Limestone Member of the Blue Lias Formation (Ambrose, 2001).
Parent Unit: Granby Member (GRBL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Fulbeck Airfield Borehole F/B5 (SK95SW/17). 
Reference(s):
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). 
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. 
Ambrose, K, 2001. The lithostratigraphy of the Blue Lias Formation (Late Rhaetian-Early Sinemurian) in the southern part of the English Midlands. Proceedings of the Geologists' Association, Vol.112, 97-110. 
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