The BGS Lexicon of Named Rock Units — Result Details

Cwm-Amliw Tuff Formation

Computer Code: CMA Preferred Map Code: notEntered
Status Code: Index Level
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: none recorded or not applicable
Definition of Lower Boundary: none recorded or not applicable
Definition of Upper Boundary: none recorded or not applicable
Thickness: c.35m
Geographical Limits: Cwm-Amliw, near Builth Wells, Powys.
Parent Unit: Builth Volcanic Group (BUVO)
Previous Name(s): Cwm-Amliw Group (-139)
Cwm-Amliw Series (-2101)
Alternative Name(s): none recorded or not applicable
Type Area  The area around Cwm-Amliw, near Builth Wells, Powys. 
Jones, O T and Pugh, W J. 1941. The Ordovician rocks of the Builth District. A preliminary account. Geological Magazine, Vol.78, p.190. 
Schofield, D I, Davies, J R, Waters, R A, Williams, M and Wilson, D. 2004. The Builth Wells District - a brief explanation of the geology. Sheet explanation of the British Geological Survey 1:50 000 Sheet 196 Builth Wells (England and Wales). (Keyworth, Nottingham: British Geological Survey). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E196 E179