The BGS Lexicon of Named Rock Units — Result Details

Garburn Dacite Formation

Computer Code: GAD Preferred Map Code: GaD
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: A flow-foliated and brecciated plagioclase-phyric dacite, interpreted as lava.
Definition of Lower Boundary: Taken as the base of the dacite overlying volcaniclastic sandstone of the Esk Pike Formation. The two are mostly separated by later syn-BVG andesite intrusions.
Definition of Upper Boundary: Defined by overlying sedimentary rocks of the Windermere Supergroup.
Thickness: To 100m
Geographical Limits: On the north side of Garburn Pass, from near Limefitt Park [NY 420 033] via Garburn, Buck Crag [NY 440 048] and Piked Howes [NY 446 050] to Goat House Crag, Kentmere [NY 451 046], east of Kentmere from Stile End [NY 469 049] to South of Wray Crag [NY 476 052].
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Garburn Formation [Part] (-272)
Garburn Formation (-4664)
Upper Rhyolites (-2811)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Garburn, between Troutbeck and Kentmere, 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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039