The BGS Lexicon of Named Rock Units — Result Details

Brock Crags Andesite Formation

Computer Code: BKCG Preferred Map Code: BkCg
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Locally brecciated andesite lavas, with thin intercalations of lapilli-tuff and volcaniclastic sandstone.
Definition of Lower Boundary: Taken at the base of the autobrecciated andesite overlying a few metres of sandstone of the Esk Pike Sandstone Formation. In some poorly exposed areas it may overlie silicic lapilli-tuff of the Lincomb Tarns Tuff Formation.
Definition of Upper Boundary: Not seen.
Thickness: To at least 290m
Geographical Limits: Brock Crags to Angle Tarn, south of Ullswater, Cumbria.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Brock Crags, about 1 km northeast of Hartsop, Ullswater, Cumbria. 
Woodhall, D G. 2000. The geology of the Haweswater and Martindale areas of the north-eastern Lake District. British Geological Survey Technical Report WA/00/55. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039