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
Type Area  Great Worm Crag, 1:50,000 Sheet 38 (Ambleside), O.S. 1:50,000 Sheet 96 South Lakeland. 
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: