The BGS Lexicon of Named Rock Units — Result Details

Glebe Farm Bed

Computer Code: GLBF Preferred Map Code: GF
Status Code: Full
Age range: Sinemurian Age (JS) — Sinemurian Age (JS)
Lithological Description: Grey, brown weathering, bioclastic limestone bed up to 0.1m thick, with abundant bivalve fragments and limestone pebbles, overlain by brownish grey, weathering to reddish, ferru-ooidal limestone/calcareous ooidal ironstone bed up to 0.3m thick. Fauna includes gastropods, bivalves, forams, ammonites, belemnites and crinoids.
Definition of Lower Boundary: Sharp change up (probably an erosive non-sequence) from mudstone with argillaceous limestone nodules of undifferentiated Foston Member into limestone with pebbles as above; at 182.60m depth in type section Copper Hill Borehole (SK94SE/56). Base of Glebe Farm Bed marks base of Charmouth Mudstone Formation in this area.
Definition of Upper Boundary: Change up from limestone/ironstone as above into grey mudstone of Charmouth Mudstone Formation; at 182.40m depth in type section Copper Hill Borehole (SK94SE/56).
Thickness: 0.2 to 0.5m; 0.20m in type section.
Geographical Limits: East Midlands: north Leicestershire to Linclonshire. Not recognised in the Charmouth Mudstone Formation of north Lincolnshire, or south Leicestershire, where it passes south into mudstone-dominated Charmouth Mudstone formation.
Parent Unit: Charmouth Mudstone Formation (CHAM)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  BGS Copper Hill Borehole (SK94SE/56). 
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). 
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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E127 E142 E126