The BGS Lexicon of Named Rock Units — Result Details

Holehouse Gill Mudstone Formation

Computer Code: HLH Preferred Map Code: Hlh
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Mudstone, dark grey, with interbeds of sandstone and conglomerate.
Definition of Lower Boundary: Base of mudstones, unconformably overlying bedded tuffs of the Duddon Hall Formation.
Definition of Upper Boundary: Overlain by various formations, including Ulpha Formation (andesite), Wallowbarrow Formation (andesitic lapilli-tuff) and Dunnerdale Formation (volcaniclastic sandstone).
Thickness: 0 to 450m.
Geographical Limits: Northwest side of Dudden Valley from Bigert Mire (SD 179 927) to The Crook (SD 207 949), Cumbria.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Holehouse Gill Formation (-2851)
Alternative Name(s): none recorded or not applicable
Type Section  Stream section in Holehouse Gill from Bobbin Mill Bridge (SD 190 926) to Holehouse Bridge. 
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: