The BGS Lexicon of Named Rock Units — Result Details

Doup Crag Tuff Member

Computer Code: DPT Preferred Map Code: DpT
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Andesitic lapilli-tuff, interbedded with some units of pyroclastic breccia and sparse beds of tuff; bedded and cross-bedded. Interpreted as a mixture of pyroclastic surge and fallout deposits
Definition of Lower Boundary: Taken at the abrupt change from massive tuff/lapilli-tuff of the main part of the Woundale Tuff Formation, to bedded and cross-bedded tuff or pyroclastic breccia; the boundary is an erosion surface
Definition of Upper Boundary: An erosion surface that is either overlapped by fluviolacustrine sedimentary rocks of the Seathwaite Fell Sandstone Formation or overlain by dacite tuff and lapilli-tuff of the Glaramara Tuff
Thickness: Up to 200m
Geographical Limits: Cumbria, on the west side of Woundale (NY405 056), via Doup Crag (NY419 092) and Park Head Fell (NY428 097] at the head of the Troutbeck valley to Threshtwaite Mouth [NY428 102]
Parent Unit: Woundale Tuff Formation (WOU)
Previous Name(s): "Bedded Tuff" (-2764)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Doup Crag to Hart Crag on the west side of the Troutbeck valley, Windermere, Cumbria 
Reference(s):
Mitchell, G H, 1929. The succession and structure of the Borrowdale Volcanic Series in Troutbeck, Kentmere and the western part of Long Sleddale (Westmorland). Quarterly Journal of the Geological Society of London, Vol. 85, 9-44. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E039