| Computer Code: |
PY |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Neoproterozoic Era (AZ)
— Neoproterozoic Era (AZ) |
| Lithological Description: |
Highly feldspathic tuffs varying in texture from conglomeratic to fine-grained, and in colour from pink and green to maroon and purple. |
| Definition of Lower Boundary: |
Drawn at the base of the coarse purple and green Feldspathic Tuff Formation where underlying rocks are not seen. |
| Definition of Upper Boundary: |
Drawn at the conformable upward passage from the Rhyolitic Tuffs Formation of the Pont-Yr-Hafed Group to the rhyolitic and keratophyric tuffs and lavas of the Rhindaston and Gignog Group. |
| Thickness: |
Not known. |
| Geographical Limits: |
South west Wales between Haycastle and Tre-Rhos, Dyfed. |
| Parent Unit: |
Pebidian Supergroup (PN)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Between Haycastle and Tre-Rhos. |
| Reference(s): |
| Thomas, H H and Jones, O T, 1912. On the Pre-Cambrian and Cambrian rocks of Brawdy, Haycastle and Brimaston, (Pembrokeshire). Quarterly Journal of the Geological Society of London, Vol.68, 374-401. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
