The BGS Lexicon of Named Rock Units — Result Details
Bodwrog Member
Computer Code: | BWG | Preferred Map Code: | Bwg |
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Status Code: | Full | ||
Age range: | Longvillian Substage (OL) — Longvillian Substage (OL) | ||
Lithological Description: | Medium- to coarse-grained sandstones and subordinate mudstones. | ||
Definition of Lower Boundary: | Overlies, probably unconformably, the Allt Fawr Rhyolitic Tuff Formation, the base not being seen due to faulting. | ||
Definition of Upper Boundary: | Gradational, conformable transition into calcareous mudstones and subordinate sandstones of the Plastirion Member, (the latter is perhaps better considered as the undivided part of the Dwyfach Formation). | ||
Thickness: | 30m | ||
Geographical Limits: | Pwllheli and Nefyn districts, North Wales. | ||
Parent Unit: | Dwyfach Formation (DWF) | ||
Previous Name(s): | Penarwel Drive Beds
(-99)
Llanbedrog Grits (-738) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Partial Type Section | Lower part of member exposed in quarry on hillside below Bodwrog Farm. Young et al., 2002. | ||
Partial Type Section | (Upper part) exposed in a small stream. | ||
Reference(s): | |||
Fitch, F J, 1967. Ignimbrite volcanism in North Wales. Bulletin Volcanologique, 30, 199-219 | |||
Young, T P, Gibbons, W and McCarroll, D. 2002. Geology of the country around Pwllheli. Memoir of the British Geological Survey, Sheet 134 (England and Wales). | |||
Matley, C A, 1938. The geology of the country around Pwllheli, Llanbedrog and Madryn, southwest Carnarvonshire. Quarterly Journal of the Geological Society of London, Vol.94, 555-606. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
none recorded or not applicable |