The BGS Lexicon of Named Rock Units — Result Details

Wallowbarrow Tuff Formation

Computer Code: WAL Preferred Map Code: Wal
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Massive, andesitic lapilli-tuff and pyroclastic breccia.
Definition of Lower Boundary: Base of andesitic lapilli-tuff and pyroclastic breccia, unconformably overlying Duddon Hall Tuff Formation (bedded air-fall tuff), Ulpha Andesite Formation (andesitic lava) Holehouse Gill Mudstone Formation (mudstone and sandstone).
Definition of Upper Boundary: Defined by bases of overlying formations; usually the Dunnerdale Sandstone Formation (volcaniclastic sandstone) but locally the Lickle Tuff Formation (rhyolitic and dacitic tuff).
Thickness: 0 - 70m
Geographical Limits: Grassguards Fault (SD 220 970) to Hutton (SD 204 902) and Holehouse Gill (SD 183 930) in the Duddon Valley, Cumbria.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Wallowbarrow Formation (-1263)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  In the vicinity of the Wallowbarrow Crag. 
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. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E038 E048