The BGS Lexicon of Named Rock Units — Result Details

Dale Head Breccia Member

Computer Code: DHD Preferred Map Code: DHd
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Massive units of heterolithic volcaniclastic breccia and sandstone.
Definition of Lower Boundary: Base of volcaniclastic breccia and sandstone. Overlies unnamed basaltic andesite lava and locally a thin (3m) tuff. Probably unconformable.
Definition of Upper Boundary: Succeeded by overlying parts of the Birker Fell Andesite Formation, including the Cockley Beck Tuff (garnetiferous, dacitic lapilli tuff) and a variety of basaltic andesite and andesite lava.
Thickness: 0 - 220m
Geographical Limits: Dale Head - Cockley Beck area in the Duddon Valley, Cumbria.
Parent Unit: Birker Fell Andesite Formation (BFA)
Previous Name(s): Dale Head Member (-2751)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Dale Head to Rowantree How. 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E038