| Computer Code: |
BDP |
Preferred Map Code: |
Bdp |
| Status Code: |
Full |
| Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
| Lithological Description: |
White to pink weathered rhyolitic, high-grade lava-like tuff; garnetiferous. |
| Definition of Lower Boundary: |
Base of rhyolitic, lava-like tuff. Unconformable on various units within the underlying Long Top Tuffs of Airy's Bridge Tuff Formation. |
| Definition of Upper Boundary: |
By overlying Crinkle Member of Airy's Bridge Tuff Formation. |
| Thickness: |
40 - 400m |
| Geographical Limits: |
Borrowdale, Eskdale to Langdale. Hard Knott (NY 233 025) to White Gill Crag (NY 298 070), Cumbria. |
| Parent Unit: |
Crinkle Tuff Member (CRK)
|
| Previous Name(s): |
Bad Step Tuff Member [Obsolete Name and Code: Use BDP]
(-3831)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Bad Step near the summit of Crinkle Crags. |
| Reference(s): |
| Millward, D, Johnson, E W, Beddoe-Stephens, B, Young, B, Kneller, B C, Lee, M K, Fortey, N J, Allen, P M, Branney, M J, Cooper, D C, Hirons, S, Kokelaar, B P, Marks, R J, McConnell, B J, Merritt, J W, Molyneux, S G, Petterson, M G, Roberts, B, Rundle, C C, Rushton, A W A, Scott, R W, Soper, N J, and Stone, P. 2000. Geology of the Ambleside district. Memoir of the British Geological Survey, England and Wales, Sheet 38. |
| Branney, M J, Kokelaar, B P, and McConnell, B J. 1992. The Bad Step Tuff: a lava-like rheomorphic ignimbrite in a calc-alkaline piecemeal caldera, English Lake District. Bulletin Volcanology, Vol. 54, 187-199. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E038
E029
|
