The BGS Lexicon of Named Rock Units — Result Details

Granby Member

Computer Code: GRBL Preferred Map Code: Gby
Status Code: Full
Age range: Hettangian Age (JH) — Sinemurian Age (JS)
Lithological Description: Grey calcareous mudstones with numerous thin, laterally persistent, shelly, bioclastic limestones occurring in groups and comprising more than 10% of the sequence.
Definition of Lower Boundary: Base of lowest limestone in unit; at 87.35m in type section, borehole F/B5 (SK95SW/17); at top of Barnby Member.
Definition of Upper Boundary: Top of highest limestone in unit; at 56.75m in type section borehole F/B5 (SK95SW/17), at base of Beckingham Member.
Thickness: 30.60m in borehole F/B5.
Geographical Limits: East Midlands Shelf (south Yorkshire to London Platform area).
Parent Unit: Scunthorpe Mudstone Formation (SMD)
Previous Name(s): Granby Limestones (-3440)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Fulbeck Airfield Borehole F/B1 (SK85SE/25), depths 40.5 to 70.9m 
Type Section  Fulbeck Airfield Borehole F/B5 (SK95SW/17), depths 56.75 to 87.35m 
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. 
Sumbler, M G, 1987. Geological Notes and Local Details for 1:10,000 Sheet SK85SE (Beckingham). British Geological Survey Technical Report. 
Sumbler, M G, 1987. Geological Notes and Local Details for 1:10,000 Sheet SK95SW (Brant Broughton). British Geological Survey Technical Report. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E127 E142