The BGS Lexicon of Named Rock Units — Result Details

Pandy Tuff Formation

Computer Code: PAT Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Soudleyan Substage (OY) — Longvillian Substage (OL)
Lithological Description: Welded and non-welded felsic ash-flow lapilli crystal tuffs and thin mudstones.
Definition of Lower Boundary: Conformable sharp junction with underlying siltstones and mudstones of the Teirw Siltstone Formation.
Definition of Upper Boundary: Conformable gradational junction with the Bryn Siltstone Formation.
Thickness: To 37m
Geographical Limits: Not defined.
Parent Unit: Not Available (!)
Previous Name(s): Pandy Tuff (-3605)
Pandy Ash (-1113)
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
Reference(s):
Brenchly, P J, 1964. Ordovician ignimbrites in the Berwyn Hills, North Wales. Geological Journal, Vol.4, 43-54 
Brenchley, P J, 1978. The Caradocian rocks of the North and West Berwyn Hills. Geological Journal, Vol.13, 137-164. 
Wedd, C B, Smith, B, King, W B R and Wray, D A. 1929. Geology of the country around Oswestry. Memoir of the Geological Survey of Great Britain, Sheet 137. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E120 E136 E137