The BGS Lexicon of Named Rock Units — Result Details

Bailey's Beds

Computer Code: BLEY Preferred Map Code: notEntered
Status Code: Index Level
Age range: Asbian Substage (CR) — Brigantian Substage (CX)
Lithological Description: Dark grey to black, faintly laminated, siliceous shaly mudstones, with interbedded pale grey weathering limestone and mudstones towards the top.
Definition of Lower Boundary: The lower boundary is taken at the incoming of dark grey to black siliceous mudstones above blocky chert with few limestones of the Kersdown Chert Member.
Definition of Upper Boundary: The upper boundary is taken at the top of the uppermost limestone bed within the Baileys Member, overlain sharply by relatively soft, black shaly mudstone of the Dowhills Formation.
Thickness: About 30 m
Geographical Limits: Between Upcott, near Brushford (SS 90 25) and Hockford Waters (ST 01 21), Somerset
Parent Unit: Bampton Limestone Formation (BPLM)
Previous Name(s): Upper Bampton Limestones [Obsolete Name and Code: Use BLEY, BPLM] (-3225)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Kiln Cottage quarry, Bampton, Somerset. The upper c. 23 m thickness of the member is seen, along with the lower boundary of the overlying Dowhills Formation. Described by Whiteley (2004). 
Reference Section  Kersdown quarry, Bampton, Somerset. The lower c. 15 m thickness of the member is seen in the core of an anticline, along with the lower boundary of the underlying Kersdown Chert Member. Described by Whiteley (2004). 
Reference(s):
Whiteley, M J. 2004. Culm Trough. 477-504 in British Lower Carboniferous Stratigraphy. Cossey, P J, Adams,A E, Purnell, M A, Whiteley, M J, Whyte, M A and Wright, V P (editors). Geological Conservation Review Series, No 29. (Peterborough: Joint Nature Conservation Committee). 
Thomas, J M. 1962. The Culm Measures in north-east Devon. Proceedings of the Ussher Society, Vol. 1, 29-30. 
Webby, B D. and Thomas, J M. 1965. Whitsun field meeting: Devonian of west Somerset and the Carboniferous of north-east Devon. Proceedings of the Geologists Association, Vol. 76, 179-194. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable