The BGS Lexicon of Named Rock Units — Result Details

Penrhos Member

Computer Code: PNR Preferred Map Code: Pr
Status Code: Pending Upgrade
Age range: St David's Series (ED) — Merioneth Series (EM)
Lithological Description: Locally recognisable member of the Maentwrog Formation (Pratt, Woodhall and Howells, 1995).
Definition of Lower Boundary: none recorded or not applicable
Definition of Upper Boundary: none recorded or not applicable
Thickness: none recorded or not applicable
Geographical Limits: none recorded or not applicable
Parent Unit: Maentwrog Formation (MW)
Previous Name(s): Penrhos Slates [Obsolete Name And Code: See PNR] (PESL)
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
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. 
Pratt, W T, Woodhall, D G and Howells, M F. 1995. Geology of the country around Cadair Idris. Memoir of the British Geological Survey, Sheet 149. (England and Wales). (London: HMSO), 111pp 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E149