| 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 [Obsolete Name and Code: Use WAL]
(-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
|
