The Skomer Volcanic Group is a Silurian lithostratigraphic group (a sequence of rock strata) in Pembrokeshire, Wales. The name is derived from the island of Skomer off the west coast of Pembrokeshire. It was traditionally known as the Skomer Volcanic Series. The rocks are exposed across the island of Skomer and along the northern half of the nearby Marloes peninsula as far east as St Ishmaels.[1][2]

Group
Stratigraphic range: Silurian
TypeGroup
Underliesupper Llandovery shales and sandstone
OverliesOrdovician rocks
Thicknessabout 1000m
Lithology
Primarylava flows
Otherbreccias, conglomerates, quartzitess, clay rocks
Location
RegionWest Wales
CountryWales
ExtentSkomer and adjacent parts of mainland Wales
Type section
Named forSkomer island

Lithology and stratigraphy

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The Group comprises around 1000m thickness of lava flows and associated strata including felsite, albite-trachyte, keratophyre etc laid down during the Silurian Period.[3]

References

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  1. ^ British Geological Survey 1:50,000 scale geological map (England & Wales) sheet 226/227 Milford
  2. ^ Ziegler, A. M.; McKerrow, W. S.; Burne, R. V.; Baker, P. E. (1969-01-01). "Correlation and environmental setting of the Skomer Volcanic Group, Pembrokeshire". Proceedings of the Geologists' Association. 80 (4): 409–439. doi:10.1016/S0016-7878(69)80031-3. ISSN 0016-7878.
  3. ^ https://webapps.bgs.ac.uk/Lexicon/lexicon.cfm?pub=SVG (BGS on-line lexicon of rock units)