The BGS Lexicon of Named Rock Units — Result Details
Skomer Volcanic Group
| Computer Code: | SVG | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Aeronian Age (SA) — Aeronian Age (SA) | ||
| Lithological Description: | Subaerial lava flows with breccias, conglomerates, quartzites and red clayrocks. Mafic to felsic, including felsite, albite-trachyte, keratophyre, skomerite, marloesite, mugearite and olivine basalt. | ||
| Definition of Lower Boundary: | Drawn at the base of the Skomer Volcanic Group (which is never seen) where it unconformably overlies Ordovician rocks. | ||
| Definition of Upper Boundary: | Drawn at the conformable upward passage of the Skomer Volcanic Group where it is unconformably overlain by upper Llandovery shales and sandstone. | ||
| Thickness: | 1000 metres approx. | ||
| Geographical Limits: | Skomer Island off the Pembrokeshire coast. | ||
| Parent Unit: | Not Applicable (-) | ||
| Previous Name(s): | Conglomerate "Series" [Obsolete Name And Code: Use SVG]
(CGT)
Skomer Volcanic Series [Obsolete Name and Code: Use SVG] (-3703) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | Skomer Island | ||
| Reference(s): | |||
| Cantrill, T C and others, 1916. South Wales Coalfield, part XII, Milford. Memoir of the Geological Survey of Great Britain. | |||
| Thomas, H H. 1911. The Skomer Volcanic Series, Pembrokeshire. Quarterly Journal of the Geological Society of London, Vol.67, p.211. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| none recorded or not applicable | |||