The BGS Lexicon of Named Rock Units — Result Details
Lag Bank Tuff Formation
Computer Code: | LBT | Preferred Map Code: | LBT |
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Status Code: | Full | ||
Age range: | Caradoc Series (O4) — Caradoc Series (O4) | ||
Lithological Description: | Dacitic lapilli-tuff, poorly sorted, massive, containing abundant white-weathered plagioclase-phyric dacite lapilli. | ||
Definition of Lower Boundary: | Base of dacitic lapilli tuff. Unconformably overlies Caw Formation (volcaniclastic breccia and sandstone) and Lickle Formation (rhyolitic and dacitic tuff). | ||
Definition of Upper Boundary: | Contact with overlying Seathwaite Fells Formation (volcaniclastic sandstone). | ||
Thickness: | 0 to 600m | ||
Geographical Limits: | Ulpha Basin and Coniston Fells. Postlethwaite Allotment (SD 240 930) to Pikes (SD 237 947) and northeast to Low Water (SD 270 980), Cumbria. | ||
Parent Unit: | Borrowdale Volcanic Group (BVG) | ||
Previous Name(s): | Lag Bank Tuff [Obsolete Name and Code: Use LBT]
(-2892)
Lag Bank Formation [Obsolete Name and Code: Use LBT] (-1640) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Area | In the vicinity of Lag Bank (SD 246 943); Postlethwaite Allotment (SD 24 93) to Pikes (SD 237 947). | ||
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. | |||
Mitchell, G H, 1956. (Undivided Lickle Rhyolites). The Borrowdale Volcanic Series of the Dunnerdale Fells, Lancashire. Liverpool and Manchester Geological Journal, Vol.1, p.428-449. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
E038 |