The BGS Lexicon of Named Rock Units — Result Details

Coldbeck Limestone Formation

Computer Code: CLK Preferred Map Code: CLK
Status Code: Pending Upgrade
Age range: Chadian Substage (CI) — Chadian Substage (CI)
Lithological Description: Dark grey, fine-grained limestones with interbedded mudstones and flaggy dolomites characterised by abundance of algal macrostructures including stromatolites and oncolites. Overlying Park Hill Limestone is more bioclastic, contains productoid brachiopods, is more dolomitic and lacks abundance of algal macrostructures. The upper part of underlying Stone Gill Limestone has thick-bedded porcellanous limestones and thin-bedded dolomites with 'Camarotoechia proava'.
Definition of Lower Boundary: At base of 'Spongiostroma Band' of Turner, 1950. (Stone Gill, Ravenstonedale).
Definition of Upper Boundary: At top of Algal Nodular Beds under Coldbeck Bridge. (Stone Gill, Ravenstonedale).
Thickness: 52 metres strata visible in continuous section in Stone Gill but Turner (1950,p.30) estimated that a further 31 metres are cut out by faulting. Maintains a thickness of about 50 metres across NY60NE and NY60NW as far as Gaisgill, then thins westward to 20 metres at west edge of NY60NW.
Geographical Limits: Not defined.
Parent Unit: Great Scar Limestone Group (GSCL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Base at Stone Gill, Ravenstonedale, Cumbria, Sheet 40. 
Reference(s):
none recorded or not applicable
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E040