Computer Code: |
STF |
Preferred Map Code: |
Stf |
Status Code: |
Full |
Age range: |
Caradoc Series (O4)
— Caradoc Series (O4) |
Lithological Description: |
White-weathered, flinty, bedded and cross-bedded rhyodacitic tuff and accretionary lapilli-tuff |
Definition of Lower Boundary: |
Taken at the base of bedded silicic tuff overlying andesitic tuff of the Whorneyside Formation; in places including in the reference section, there is an angular discordance at the base. |
Definition of Upper Boundary: |
Defined by the overlying eutaxitic lapilli-tuff of the main part of the Long Top Tuff Member. |
Thickness: |
Up to 6m |
Geographical Limits: |
Cumbria. Thirlwell to Scafell and Stonesty Pike, central Lake District, occurring at the base of the Long Top Tuff Member except where the Oxendale Tuff is present. |
Parent Unit: |
Long Top Tuff Member (LTT)
|
Previous Name(s): |
Stonesty Tuff Member [Obsolete Name and Code: Use STF]
(-1202)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Reference Section |
Stonesty Pike, 2.5km north of Cockley Beck Bridge, Upper Duddon Valley, Cumbria Branney et al., 1993 |
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, Davis, N C, Kokalaar, B P and McConnell, B J. 1993. The Airy's Bridge Formation in the central Fells. British Geological Survey Technical Report WA/93/41 |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |