The BGS Lexicon of Named Rock Units — Result Details

Fishguard Volcanic Group

Computer Code: FIV Preferred Map Code: notEntered
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 (-252)
Fishguard Volcanic Series (-910)
Alternative Name(s): none recorded or not applicable
Type Area  Fishguard area, Dyfed, Wales. 
Bevins, R E and others, 1989. Ordovician intrusions of the Strumble Head-Mynydd Preseli region, Wales: lateral extensions of the Fishguard Volcanic Complex. 
Bevins, R E, 1982. Petrology and geochemistry of the Fishguard Volcanic Complex, Wales. Geological Journal, Vol.17 (1), p.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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: