The BGS Lexicon of Named Rock Units — Result Details

Dog Crag Tuff Member

Computer Code: DCT Preferred Map Code: DCT
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Eutaxitic lapilli-tuff, composition probably dacitic (or andesitic), interpreted as pyroclastic flow deposit.
Definition of Lower Boundary: Base of lapilli-tuff rests on a non-sequence that occurs at the top of the Whinny Bank Formation - an interbedded succession of siltstone and andesitic lapilli-tuff.
Definition of Upper Boundary: Parallel bedded tuff and lapilli-tuff of the Po House Tuff Formation.
Thickness: To 30m
Geographical Limits: Wicham Valley:- between Bankside (SD 158 831) and Lacra Bank (SD 145 815)
Parent Unit: Po House Tuff Formation (PHT)
Previous Name(s): Po House Tuffs (Part) (-857)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Dog Crag, Po House Bank, Whicham Valley, Cumbria. 
Reference(s):
Mathieson, N A, 1986 Geology, structure and geochemistry of the Ordovician volcanic succession in south west Cumbria. Unpublished Ph.D. thesis, University of Sheffield. 
Green, J F N, 1913. The older Palaeozoic succession of the Dudden Estuary. London, 23pp. 
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). 
British Geological Survey 1994a. Silecroft, SD18SW solid and drift 1:10,000 (Keyworth, Nottingham, British Geological Survey). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E048