| Computer Code: |
PVT |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
| Lithological Description: |
Fragments of vesicular trachyte, augite andesite and quartz rhyolite in red matrix as well as fragments of reddish trachyte in green gritty matrix. |
| Definition of Lower Boundary: |
Drawn at base of green grit with trachyte fragments where it rests conformably on feldspathic grit of the Penrhiw Group. |
| Definition of Upper Boundary: |
Drawn at conformable upward passage from red grit of the Treginnis Group to green grit and clegyr conglomerate of the Caerbwdy Group. |
| Thickness: |
180 - 220m approx. |
| Geographical Limits: |
South-west Wales. |
| Parent Unit: |
Pebidian Supergroup (PN)
|
| Previous Name(s): |
Treginnis Series [Obsolete Name and Code: Use PVT]
(-4278)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Treginnis-Uchaf Farm, St. David's, Dyfed, Wales. |
| Reference(s): |
| Harris, A L and others, 1973. A correlation of the Pre-Cambrian rocks in the British Isles. Geological Society of London Special Report No 6. |
| Pringle, J and George, T N, 1948. South Wales. British Regional Geology. |
| Green, J F N. 1908. The geological structure of the Saint David's area (Pembrokeshire). Quarterly Journal of the Geological Society of London, Vol. 64, 363-383. |
| Cox, A H, Green, J F N, Jones, O T, and Pringle, J. 1930. The Geology of the St David's district, Pembrokeshire. Proceedings of the Geologists' Association, Vol. 41, 241-273. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
