The BGS Lexicon of Named Rock Units — Result Details
Pen y gadair Volcanic Formation
| Computer Code: | PGA | Preferred Map Code: | PgV |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Caradoc Series (O4) — Caradoc Series (O4) | ||
| Lithological Description: | Massive, pillowed and autobrecciated basalt lavas with intercalated crystal tuffs and subordinate felsic ash-flow tuffs, locally interbedded with mudstones. | ||
| Definition of Lower Boundary: | Conformably overlies and interdigitates laterally with the Ty'r Gawen Mudstone Formation to the southwest, and with the Benglog Formation to the northeast. | ||
| Definition of Upper Boundary: | Conformably overlain by mudstones of the Ty'r Gawen Formation. | ||
| Thickness: | To 240m | ||
| Geographical Limits: | Cadair Idris and Dolgelly areas, North Wales. | ||
| Parent Unit: | Aran Volcanic Group (AVG) | ||
| Previous Name(s): | Upper Basic (Volcanic) Group [Obsolete Name and Code: Use PGA]
(-2976)
Pen-Y-Gader Volcanic Group [Obsolete Name and Code: Use PGA] (-4255) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | Crags, on and to west of Penygadair, Cadair Idris area, North Wales. Pratt, W T, Woodhall, D G and Howells, M F. 1995. | ||
| Reference(s): | |||
| 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 | |||
| Cox, A H, and Wells, A K. 1927. The geology of the Dolgelley district, Merionethshire. Proceedings of the Geologists' Association, Vol.38, 265-318. | |||
| Cox, A H. 1925. The geology of the Cadair Idris Range, (Merioneth). Quarterly Journal of the Geological Society of London, Vol.81, p.539-592. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E149 | |||