The BGS Lexicon of Named Rock Units — Result Details

Cross Lane Limestones Bed

Computer Code: CSLL Preferred Map Code: CL
Status Code: Full
Age range: Hettangian Age (JH) — Hettangian Age (JH)
Lithological Description: Group of several (seven at type section) thin (typically 0.1m) limestone units separated by mudstone beds. The limestone beds are shelly, pale grey, weathering pale brown, with abundant coarse sand-grade shell debris. Fauna includes forams, serpulids, gastropods, bivalves and echinoderms. The lower part forms a positive feature.
Definition of Lower Boundary: Change up from grey, calcareous mudstone of the undifferentiated Granby Member; at 76.26m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Definition of Upper Boundary: Change up into grey, calcareous mudstone of the undifferentiated Granby Member; at 76.34 m depth in type section Fulbeck Airfield Borehole F/B5 (SK95SW/17).
Thickness: 1.5 to 2m; 1.92m in type section.
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 more argillaceous and less bioclastic Rugby Limestone Member of the Blue Lias Formation (Ambrose, 2001).
Parent Unit: Granby Member (GRBL)
Previous Name(s): Cross Lane Limestone (-824)
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). 
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). 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E127 E142 E126