The BGS Lexicon of Named Rock Units — Result Details

Millom Park Formation [Obsolete Name: Part Of WB]

Computer Code: MPA Preferred Map Code: MPa
Status Code: Index Level
Age range: Abereiddian Stage (O2) — Caradoc Series (O4)
Lithological Description: Dacitic lapilli-tuff and tuff. Mostly massive with some interbeds of parallel bedded tuff. Intruded by basalt, basaltic andesite and andesite and locally contains intercalated andesite lava.
Definition of Lower Boundary: Unconformity. Overlies less widely distributed older Formations (Po House and Whinney Bank) in the Borrowdale Volcanic Group and locally rests directly on the Skiddaw Group.
Definition of Upper Boundary: Parallel bedded tuffs of the Duddon Hall Formation.
Thickness: 1800-2600m
Geographical Limits: Beckfoot (SD 194 899) to Kirksanton (SD 140 807), south-east of Whicham Valley, Cumbria.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Middle Tuffs (-405)
A Variety Of Local Names (-1707)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Millom Park, north of Millom, Cumbria. 
Reference Section  Between Knott Hill and Beckfoot. 
Reference(s):
Johnson, E W, Soper, N J, Burgess, I C, Ball, D F, Beddoe-Stephens, B, Carruthers, R M, Fortey, N J, Hirons, S, Merritt, J W, Millward, D, Roberts, B, Walker, A B and Young, B. 2001. Geology of the country around Ulverston. Memoir of the British Geological Survey, England and Wales, Sheet 48. 
British Geological Survey, 1994(b). Millom Park, SD18SE, Solid and Drift, 1:10,000 (Keyworth, Nottingham, British Geological Survey). 
Mathieson, N A, 1986 Geology, structure and geochemistry of the Ordovician volcanic succession in south west Cumbria. Unpublished Ph.D. thesis, University of Sheffield. 
British Geological Survey, 1994(a). Duddon Bridge and Hallthwaites, SD18NE, Solid and Drift 1:10,000. (Keyworth, Nottingham, British Geological Survey). 
Green, J F N, 1913. The older Palaeozoic succession of the Dudden Estuary. London, 23pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable