The BGS Lexicon of Named Rock Units — Result Details

Goat Scar Dacite Member

Computer Code: GSD Preferred Map Code: GSD
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Dacite, interpreted to be a lava dome with associated coulee-type flow, partly intrusive and partly extrusive, interbedded with lapilli-tuff.
Definition of Lower Boundary: Irregular contact with lower ignimbrite sheet of the Lincomb Tarns Tuff Formation, which discordant relationship suggests that the lower parts of the dacite are intrusive. Elsewhere the dacite overlies the ignimbrite, but is obscured in places by later syn-BVG andesite intrusions.
Definition of Upper Boundary: Overlain by upper ignimbrite sheet of the Lincomb Tarns Tuff Formation, but separated from it by later syn-BVG andesite intrusions.
Thickness: To 600m
Geographical Limits: From Hallow Bank Quarter, Kentmere [NY 463 060], via Goat Scar to the south of Buckbarrow Crag on the east side of Longsleddale [NY 484 072], Cumbria.
Parent Unit: Lincomb Tarns Tuff Formation (LTA)
Previous Name(s): Kentmere Pike Rhyolites (-943)
Kentmere Formation (-2218)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Goat Scar on the west side of Longsleddale, Cumbria. Johnson, E W. (In prep.) 
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. 
Soper, N J and Numan, N M S, 1974. Structure and stratigraphy of the Borrowdale Volcanic Rocks of the Kentmere area, English Lake District. Geological Journal, Vol. 9, 147-166. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039