The BGS Lexicon of Named Rock Units — Result Details

Caerbwdy Group

Computer Code: PVC Preferred Map Code: PVC
Status Code: Pending Upgrade
Age range: Ediacaran Period (AD) — Ediacaran Period (AD)
Lithological Description: Fine- to coarse-grained, feldspathic and porcellanitic ("halleflinta") crystal lithic tuffs, with volcaniclastic conglomerates in the lower part.
Definition of Lower Boundary: Unknown; appears to be conformable on Lower Pebidian strata (undivided).
Definition of Upper Boundary: Unknown; appears to be conformably overlain by the Ramsey Sound Group.
Thickness: At least 600m
Geographical Limits: St David's area, Pembrokeshire.
Parent Unit: Pebidian Supergroup (PN)
Previous Name(s): Caerbwdy Series [Obsolete Name and Code: Use PVC] (-3626)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Crags to the east of Treginnis-isaf. Within the lower part of the succession. 
Reference Section  Quarries along the Caerbwdy Valley, south of Trevinert. Green, 1908 
Reference(s):
Bevins, R E amd Horak, J. 2000. St David's Peninsula. 131-136 in Carney, J (Editor), Precambrian Rocks of England and Wales. Geological Conservation Review Series, 20. [Peterborough: Joint Nature Conservation Committee.] 
George, T N. 1970. British Regional Geology, South Wales, Third Edition. British Geological Survey. 
Green, J F N. 1908. The geological structure of the Saint David's area (Pembrokeshire). Quarterly Journal of the Geological Society of London, Vol.64, 363-383. 
Pharaoh T C and Gibbons W. 1994. Precambrian rocks in England and Wales south of the Menai Strait Fault System. 85-97 in Gibbons W and Harris A L (editors), A revised correlation of Precambrian rocks in the British Isles. Geological Society of London Special Report No.22. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E209