| 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): |
| 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 |
