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 (-3225)
Alternative Name(s): none recorded or not applicable
Stratotypes:
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 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(s):
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. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable