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
Stratotypes:
Type Area  The area west of Powley Hill, Naddle Forest, Haweswater, Cumbria. 
Reference(s):
Beddoe-Stephens, B, 2000. The Borrowdale Volcanic Group between Haweswater and eastern Ullswater. British Geological Survey Technical Report WG/00/04. 
Millward, D, 2002. Geology of the area between Haweswater and Shap. British Geological Survey Research Report RR/02/02 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039