Computer Code: |
CKT |
Preferred Map Code: |
CkT |
Status Code: |
Full |
Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
Lithological Description: |
Garnetiferous eutaxitic dacitic lapilli-tuff with thin interbedded laminated garnetiferous tuff locally. |
Definition of Lower Boundary: |
Base of garnetiferous, dacitic lapilli-tuff. Unconformable, in type area overlies volcaniclastic breccia and sandstone (Dale Head Member); elsewhere overlies a variety of basaltic, andesitic and dacitic lava. |
Definition of Upper Boundary: |
Overlain by a variety of lavas that range in composition from basaltic andesite to dacite, and locally overlain by valcaniclastic sandstone. |
Thickness: |
0 to 60m |
Geographical Limits: |
Duddon Valley - Eskdale; Cockley Beck to Dale Head and Foxbield Moss, Cumbria. |
Parent Unit: |
Birker Fell Andesite Formation (BFA)
|
Previous Name(s): |
none recorded or not applicable
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Area |
Between Cockley Beck and Dale Head Chase |
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. |
Petterson, M G, Beddoe-Stephens, B, Millward, D and Johnson, E W, 1992. The Ordovician Lower Borrowdale Volcanic Group in the English Lake District. The construction of a pre-caldera volcanic field. Journal of the Geological Society of London, Vol.149, p.889-906. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E038
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