The BGS Lexicon of Named Rock Units — Result Details

Pebidian Supergroup [Obsolete Code: Use PN]

Computer Code: PVL Preferred Map Code: PV
Status Code: Index Level
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Trachytic and andesitic tuffs and tuffaceous sediments, locally conglomeratic. NOTE: The definition follows the usage on British Geological 1:25 000 Special Sheet SM72 (St Davids), 1973, which in turn derives from GREEN, JFN, 1908.The computer code PV already exists for 'Pebidian Volcanic Series (undifferentiated)'
Definition of Lower Boundary: Not seen.
Definition of Upper Boundary: Base of Caerbwdy Group of Pebidian Volcanic Complex.
Thickness: 500m +
Geographical Limits: St Davids Sheet 209.
Parent Unit: none recorded or not applicable
Previous Name(s): Lower Pebidian [Undifferentiated] (-1779)
Pebidian Volcanic Complex (-2978)
Alternative Name(s): none recorded or not applicable
Stratotypes:
none recorded or not applicable
Reference(s):
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