The BGS Lexicon of Named Rock Units — Result Details

Powley's Hill Tuff Member

Computer Code: PLH Preferred Map Code: PlH
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: A markedly garnetiferous, heretogenous succession of crystal, pumice and lithic-rich massive beds, bedded silicic tuff and lapilli tuffs.
Definition of Lower Boundary: Taken at the abrupt change from andesite or volcaniclastic sandstone of the Birker Fell Andesite Formation to bedded silicic pyroclastic rocks.
Definition of Upper Boundary: Defined by the base of the Pinnacle Howe Member.
Thickness: To 65m
Geographical Limits: Haweswater, eastern Lake District.
Parent Unit: Whelter Knotts Tuff Formation (WLT)
Previous Name(s): Powley's Hill Member (-4260)
Alternative Name(s): none recorded or not applicable
Type Area  The area west of Powley Hill, Naddle Forest, Haweswater, Cumbria. 
Millward, D, 2002. Geology of the area between Haweswater and Shap. British Geological Survey Research Report RR/02/02 
Beddoe-Stephens, B, 2000. The Borrowdale Volcanic Group between Haweswater and eastern Ullswater. British Geological Survey Technical Report WG/00/04. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039