Computer Code: |
THW |
Preferred Map Code: |
THw |
Status Code: |
Full |
Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
Lithological Description: |
Andesitic coarse tuffs and lapilli-tuffs; massive to weakly stratified, with a very rough weathered surface exhibiting conspicuous surface holes. |
Definition of Lower Boundary: |
Change from dacitic to acid andesitic tuffs; overlies Lincomb Tarns Tuff Formation. |
Definition of Upper Boundary: |
Not seen; unconformably overlain by lowest formation of Windermere Supergroup. |
Thickness: |
0 - 420m |
Geographical Limits: |
Area between the Coniston Fault (Tarn Hows) and Lake Windermere. |
Parent Unit: |
Borrowdale Volcanic Group (BVG)
|
Previous Name(s): |
Tarn Hows Formation [Obsolete Name and Code: Use THW]
(-2485)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Area |
Tarn Hows - Iron Keld Plantation area. |
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. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E038
|