The BGS Lexicon of Named Rock Units — Result Details

Throstle Garth Basalt Member

Computer Code: TGH Preferred Map Code: TGh
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Compound lava flows of dark greenish grey aphyric to sparsely olivine-phyric basalt/basaltic andesite and interbedded volcaniclastic rocks.
Definition of Lower Boundary: Rests on andesitic and dacitic rocks of the Birker Fell Andesite Formation (undivided).
Definition of Upper Boundary: Overlain by andesitic and dacitic rocks of the Birker Fell Andesite Formation (undivided) or by the andesitic lapilli-tuff of the Whorneyside Tuff Formation.
Thickness: 0 - 310m
Geographical Limits: Green How, Horn Crag, Lingcove Beck, Hard Knott, (NY 195 068 - 243 050 - 235 015) Upper Eskdale, Cumbria.
Parent Unit: Birker Fell Andesite Formation (BFA)
Previous Name(s): Throstle Garth Member (-3078)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Crags and stream section of Throstle Garth and River Esk. 
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. 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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E038