The BGS Lexicon of Named Rock Units — Result Details

Upper Lodge Volcanic Group

Computer Code: ULV Preferred Map Code: ULG
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Basaltic trachyandesite with rhyolitic tuff.
Definition of Lower Boundary: Lies conformably on sandstones and siltstones, plus tuffs of the Cwm Eigiau Formation.
Definition of Upper Boundary: Overlain by siltstones, sandstones and calcareous mudstones of the Dwyfach Formation.
Thickness: About 500m
Geographical Limits: Pwllheli area, northwest Wales.
Parent Unit: Not Applicable (-)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Exposures near Boduan. 
Reference(s):
Rushton, A W A and Howells, M F. 1998. Stratigraphical framework for the Ordovician of Snowdonia and the Lleyn Peninsula. British Geological Survey Research Report, RR/99/08. 
Matley, C A and Heard, A, 1930. The Geology of the country around Boduan (south-west Carnarvonshire). Quarterly Journal of the Geological Society of London, Vol.86, 130-168. 
Young, T P, Gibbons, W and McCarroll, D. 2002. Geology of the country around Pwllheli. Memoir of the British Geological Survey, Sheet 134 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E134