The BGS Lexicon of Named Rock Units — Result Details

Barnstone Member

Computer Code: BNT Preferred Map Code: Bst
Status Code: Full
Age range: Rhaetian Age (TR) — Hettangian Age (JH)
Lithological Description: Alternating grey mudstones and limestones; limestones generally 0.1 metres to 0.3 metres thick, argillaceous calcilutites forming c.30% of sequence; shell debris in limestones in basal 2 - 3 metres.
Definition of Lower Boundary: Base of Lias Group: basal mudstone with sharp contact on Cotham Member of Penarth Group.
Definition of Upper Boundary: At top of highest limestone bed in Member.
Thickness: 8.1m to 8.7m in stratotypes, 9.6m at Barnstone; ranging from c.5m - 10m over area of occurence.
Geographical Limits: East Midlands Shelf area: between Market Weighton area to north, and north flank of London Platform to south.
Parent Unit: Scunthorpe Mudstone Formation (SMD)
Previous Name(s): Limestone Series (-3233)
Hydraulic Limestone Series (-712)
Strensham Series (-713)
Hydraulic Limestones [Obsolete Name And Code: See SMD, BNT, ELL] (HYDL)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Fulbeck Airfield Borehole F/B1 (SK85SE/25), depths from 92.8m to 100.9m. 
Type Section  Fulbeck Airfield Borehole F/B5 (SK95SW/17), depths 109.40m to 117.65m. 
Partial Type Section  Large flooded quarry 0.75 km south-west of Barnstone. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E127 E142 E141