The BGS Lexicon of Named Rock Units — Result Details

Carneddol Rhyolitic Tuff Formation

Computer Code: CRTU Preferred Map Code: CRT
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Rhyolitic ash-flow tuffs.
Definition of Lower Boundary: Overlies Foel Ddu Rhyodacite.
Definition of Upper Boundary: Underlies and is partly interleaved with the Yoke House Formation and (locally) Nod Glas Formation.
Thickness: 370-590m
Geographical Limits: Pwllheli area, northwest Wales.
Parent Unit: Llanbedrog Volcanic Group (LIG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Upper part of Formation, Bodgadle Member. Southwest of Mochras Uchaf. 
Partial Type Section  Lower part of formation, Nant y Gledryd. 
Reference(s):
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