The BGS Lexicon of Named Rock Units — Result Details

Cwm Clwyd Tuff Formation [Obsolete Name And Code: Use CGTU]

Computer Code: CCT Preferred Map Code: CCT
Status Code: Index Level
Age range: Soudleyan Substage (OY) — Soudleyan Substage (OY)
Lithological Description: Details as for Cefn Gwyn Tuff Member.
Definition of Lower Boundary: Not defined.
Definition of Upper Boundary: Not defined.
Thickness: Not defined.
Geographical Limits: Term still in use in the Bala and Oswestry areas.
Parent Unit: Not Entered (?)
Previous Name(s): Cwm Clwyd Ash [Obsolete Name And Code: See CCT] (KZ)
Cwm Clwyd Tuff (-3910)
Alternative Name(s): Cefn Gwyn Tuff Member
Stratotypes:
none recorded or not applicable
Reference(s):
Brenchley, P J, 1978. The Caradocian rocks of the North and West Berwyn Hills. Geological Journal, Vol.13, 137-164. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E120 E136 E137