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 | |
| Type | Group |
| Underlies | upper Llandovery shales and sandstone |
| Overlies | Ordovician rocks |
| Thickness | about 1000m |
| Lithology | |
| Primary | lava flows |
| Other | breccias, conglomerates, quartzitess, clay rocks |
| Location | |
| Region | West Wales |
| Country | Wales |
| Extent | Skomer and adjacent parts of mainland Wales |
| Type section | |
| Named for | Skomer island |
Lithology and stratigraphy
editThe 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
edit- ^ British Geological Survey 1:50,000 scale geological map (England & Wales) sheet 226/227 Milford
- ^ 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.
- ^ https://webapps.bgs.ac.uk/Lexicon/lexicon.cfm?pub=SVG (BGS on-line lexicon of rock units)