The BGS Lexicon of Named Rock Units — Result Details
Fishguard Volcanic Group
Computer Code: | FIV | Preferred Map Code: | notEntered |
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Status Code: | Full, pending ratification | ||
Age range: | Abereiddian Stage (O2) — Abereiddian Stage (O2) | ||
Lithological Description: | Rhyolitic and dacitic lavas, basaltic pillow lavas. Spilitic breccias, acid tuffs and intercalated volcaniclastic sediments. (Correlative of Fishguard Volcanic Group-Llanrian Volcanic Group. | ||
Definition of Lower Boundary: | Drawn at base of rhyolitic and dacitic lavas of the Porth Maen Melyn Volcanic Formation where it rests conformably on dark mudstones of the Aber Mawr Shale Formation. | ||
Definition of Upper Boundary: | Drawn at conformable upward passage from rhyolitic lavas of the Goodwick Volcanic Formation to dark grey mudstones of the Caerhys Shale. | ||
Thickness: | Approx. 1800 metres. | ||
Geographical Limits: | South-west Wales. | ||
Parent Unit: | Not Applicable (-) | ||
Previous Name(s): | Fishguard Volcanic Complex [Obsolete Name and Code: Use FIV]
(-252)
Fishguard Volcanic Series (-910) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Area | Fishguard area, Dyfed, Wales. | ||
Reference(s): | |||
Bevins, R E. 1982. Petrology and geochemistry of the Fishguard Volcanic Complex, Wales. Geological Journal, Vol.17 (1), 1-21. | |||
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. | |||
Evans, W D, 1945. The geology of the Preselly Hills, north Pembrokeshire. Quarterly Journal of the Geological Society, Vol.101, p.95. | |||
Bevins, R E, and others. 1989. Ordovician intrusions of the Strumble Head-Mynydd Preseli region, Wales: lateral extensions of the Fishguard Volcanic Complex. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
E210 |