The BGS Lexicon of Named Rock Units — Result Details
Birker Fell Andesite Formation
| Computer Code: | BFA | Preferred Map Code: | BFA |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Caradoc Series (O4) — Caradoc Series (O4) | ||
| Lithological Description: | Predominantly a tabular sheeted succession of feldspar-phyric andesite lava flows, usually with blocky autobreccia at the top and base, and subordinate sills; includes some basalts, dacites and subordinate volcaniclastic deposits. Distinctive units are given Member status. | ||
| Definition of Lower Boundary: | Taken at base of andesite succession unconformably overlying Skiddaw Group over most of the outcrop, except where andesites overlie bedded sandstones of the Letterbarrow Sandstone Formation in the west of the outcrop. | ||
| Definition of Upper Boundary: | Overlain by Whorneyside Formation; change to andesitic lapilli tuff. | ||
| Thickness: | To c. 2.7km. | ||
| Geographical Limits: | Stoneside Hill, west of Black Combe; Wasdale, Eskdale, Hard Knott, Harter Fell, and Devoke Water; Eskdale area, Borrowdale, Thirlmere, Matterdale Common, Gawbarrow, southeast of Ullswater, Haweswater and Swindale, Cumbria. | ||
| Parent Unit: | Borrowdale Volcanic Group (BVG) | ||
| Previous Name(s): | Lower Andesite [Obsolete Name and Code: Use BFA]
(-1977)
Stoneside Hill Formation [Obsolete Name: Part Of BFA] (STHI) Birker Fell Andesite Group [Obsolete Name and Code: Use BFA] (-3207) Ullswater Group [Obsolete Name and Code: Use BFA] (-3843) Fell Green Formation [Obsolete Name: Part Of BFA] (FGR) Mosedale Andesite Formation [Obsolete Name: Part Of BFA] (MOA) Andesite and Dacite Groups [Obsolete Name and Code: Use BFA] (-1344) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Reference Section | Haycock to Red Pike, Upper Wasdale, Cumbria. | ||
| Reference Section | High Rigg, Cumbria. | ||
| Reference Section | Hallin Fell, Cumbria. | ||
| Type Area | Devoke Water to Yoadcastle and Stainton Pike, Eskdale, Cumbria. | ||
| Reference Section | Cockley Beck to Grey Friar. | ||
| 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. | |||
| Millward, D. 2004. A stratigraphical framework for the Upper Ordovician and Lower Devonian volcanic and intrusive rocks in the English Lake District and adjacent areas. British Geological Survey, Research Report: RR/01/007. | |||
| Beddoe-Stephens, B. 2000. The Borrowdale Volcanic Group between Haweswater and eastern Ullswater. British Geological Survey Technical Report WG/00/04. | |||
| Millward, D. 2002. Geology of the area between Haweswater and Shap. British Geological Survey Research Report RR/02/02. | |||
| Woodhall, D G. 2000. The geology of the Haweswater and Martindale areas of the north-eastern Lake District. British Geological Survey Technical Report WA/00/55. | |||
| Firman, R G J, 1957. The Borrowdale Volcanic Series between Wastwater and Duddon Valley, Cumberland. Proceedings of the Yorkshire Geological Society, Vol.31, p.39-64. | |||
| Clark, L, 1964. The Borrowdale Volcanic Series between Buttermere and Cumberland. Proceedings of the Yorkshire Geological Society, Vol.34, p.343-356. | |||
| Oliver, R L, 1961. The Borrowdale Volcanic and associated rocks of the Scafell area, English Lake District. Quarterly Journal of the Geological Society of London, Vol 117, p. 377-417 | |||
| Petterson, M G, Beddoe-Stephens, B, Millward, D and Johnson, E W, 1992. A pre-caldera plateau-andesite field in the Borrowdale Volcanic Group of the English Lake District. Journal of the Geological Society, London, Vol. 149, 889-906. | |||
| Moseley, F, 1960. The succession and structure of the Borrodale Volcanic rocks south-east of Ullswater. Quarterly Journal of the Geological Society of London, Vol.116, 55-84. | |||
| Moseley, F, 1964. The succession and structure of the Borrowdale Volcanic rocks northwest of Ullswater. Geological Journal, Vol.4, 127-142. | |||
| Campbell, S D G, 1995. The Borrowdale Volcanic Group, immediately subjacent rocks, and related structure on 1:10000 sheets NY32SW and SE. British Geological Survey Technical Report WA/95/02. | |||
| Loughlin, S C, 2000. The Borrowdale Volcanic Group and related rocks on 1:10000 sheets NY31NE and NY41NW. British Geological Survey Internal Report IR/02/175. | |||
| Waters, C N, Gillespie, M R, Smith, K, Auton, C A, Floyd, J D, Leslie, A G, Millward, D, Mitchell, W I, McMillan, A A, Stone, P, Barron, A J M, Dean, M T, Hopson, P M, Krabbendam, M, Browne, M A E, Stephenson, D, Akhurst, M C, and Barnes, R P. 2007. Stratigraphical Chart of the United Kingdom: Northern Britain. (British Geological Survey.) | |||
| Beddoe-Stephens, B. 2000. The Borrowdale Volcanic Group of the Gowbarrow area, north of Ullswater, English Lake District (Sheet NY 42 SW). British Geological Survey Technical Report WG/00/05. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E038 E037 E029 E028 E048 E030 | |||