The BGS Lexicon of Named Rock Units — Result Details
Llanrian Volcanic Formation
| Computer Code: | LVG | Preferred Map Code: | LV |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Abereiddian Stage (O2) — Abereiddian Stage (O2) | ||
| Lithological Description: | Rhyolitic tuffs with interbedded mudstone. | ||
| Definition of Lower Boundary: | Drawn at the base of the Llanrian Volcanic Group where it rests conformably upon the Tetragraptus Shales. | ||
| Definition of Upper Boundary: | Drawn at the conformable upward passage of the Llanrian Volcanic Group where it cross-cuts the Didymograptus Bifidus Beds. | ||
| Thickness: | 250m. | ||
| Geographical Limits: | 1:50 000 Sheet 209 (St Davids). Llanrian, Pembrokeshire, south-west Wales. | ||
| Parent Unit: | Fishguard Volcanic Group (FIV) | ||
| Previous Name(s): | Llanrian Volcanic Group [Obsolete Name and Code: Use LVG]
(-382)
Llanrian Volcanic Series [Obsolete Name and Code: Use LVG] (-4775) |
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| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Area | The Llanrian Syncline, Llanrian, between St David's Head and Strumble Head. | ||
| Reference(s): | |||
| Cox, A H, and Jones, O T. 1913. The geology of the district between Abereiddy and Pencaer, Pembrokeshire. British Academy for the Advancement of Science Report, Birmingham 484. | |||
| Williams, A and others, 1972. A correlation of Ordivician rocks in the British Isles. Geological Society of London Special Report No.3. | |||
| Cox, A H. 1915. The geology of the district between Abereiddy and Abercastle (Pembrokeshire). Quarterly Journal of the Geological Society, Vol.71, p.273-342. | |||
| Elsden, J V. 1905. On the igneous rocks occcurring between St David's Head and Strumble Head. (Pembrokeshire). Quarterly Journal of the Geological Society. Vol 91, p.580. | |||
| Hughes C P, and others. 1982. Abereiddi Bay and the adjacent coast. "In" Bassett, M G. (Editor). Geological excursions in Dyfed, south-west Wales. p.51-63. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E209 | |||