| Computer Code: |
GDV |
Preferred Map Code: |
GdV |
| Status Code: |
Full |
| Age range: |
Abereiddian Stage (O2)
— Abereiddian Stage (O2) |
| Lithological Description: |
Rhyolite lavas and rhyolitic tuffs. |
| Definition of Lower Boundary: |
Drawn at base of rhyolitic lavas and tuffs of the Goodwick Volcanic Formation where it rests conformably on pillow lavas of the Strumble Head Volcanic Formation. |
| Definition of Upper Boundary: |
Drawn at conformable upward passage from rhyolitic lavas and tuffs of the Goodwick Volcanic Formation to calcareous flags. |
| Thickness: |
Up to 160 metres. |
| Geographical Limits: |
1:50,000 Sheet 209 (St.David's) and adjacent Sheet 210. |
| Parent Unit: |
Fishguard Volcanic Group (FIV)
|
| Previous Name(s): |
Upper Rhyolite Division [Obsolete Name and Code: Use GDV]
(-2201)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
North of Goodwick, near Fishguard, Dyfed, Wales. |
| Reference(s): |
| Thomas, G E and Thomas, T M. 1956. The volcanic rocks of the area between Fishguard and Strumble Head, Pembrokeshire. Quarterly Journal of the Geological Society, Vol.112, 291-314. |
| Bevins, R E, and Roach, R A. 1980. Early Ordovician Volcanism in Dyfed, south-west Wales. 603-609 in The Caledonides of the British Isles Reviewed. Harris, A L, Holland, C H, and Leake, B E (editors). Geological Society Special Publication, No. 8. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E209
|
