The BGS Lexicon of Named Rock Units — Result Details

Worm Crag Formation [Obsolete Name: Rocks Now Included In WNY And AIB]

Computer Code: WCF Preferred Map Code: WCF
Status Code: Index Level
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Andesitic tuff-breccia and lapilli tuff; locally with a eutaxitic texture markedly heterolithic.
Definition of Lower Boundary: Base taken at change in lithology (from lavas to tuff-breccia).
Definition of Upper Boundary: Overlain by bedded tuffs of the Crosbythwaite Formation or rhyodacitic lapilli tuffs of the Waberthwaite Formation.
Thickness: About 200 metres.
Geographical Limits: Not defined.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Worm Crag Group (-602)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Great Worm Crag, 1:50,000 Sheet 38 (Ambleside), O.S. 1:50,000 Sheet 96 South Lakeland. 
Reference(s):
Millward D. 2004.A stratigraphical framework for the Upper Ordovician and Lower Devonian volcanic and intrusive rocks in the English Lake District and adjacent areas. British Geological Survey, Research Report: RR/01/007. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E038