The BGS Lexicon of Named Rock Units — Result Details

Skerries Formation

Computer Code: NK Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Ediacaran Period (AD) — Ediacaran Period (AD)
Lithological Description: Massive greenish-grey schistose greywackes, coarse and often pebbly, followed by unstratified dull greenish-grey pyroclastic rocks of intermediate composition.
Definition of Lower Boundary: Drawn at the base of the Skerries Formation where it rests conformably upon pelites and semipelites with pillow lavas of the New Harbour Group.
Definition of Upper Boundary: Drawn at the conformable upward passage from the top of the Church Bay Tuff Formation to the limestone, graphitic pelite and other quartzite;- triple formation of the Gwna Group.
Thickness: 500 metres approx.
Geographical Limits: Anglesey, north Wales.
Parent Unit: New Harbour Group (NNH)
Previous Name(s): Skerries Conglomerates (NKSC)
Skerries Grits (NKSG)
Skerries Group (-421)
Alternative Name(s): none recorded or not applicable
Type Area  The Skerries, near Carmel Head, Anglesey. 
Greenly, E. 1919. The geology of Anglesey, Vol 1. Memoir of the Geological Survey of Great Britain (England and Wales). (London: H.M.S.O.). 
Harris, A L and others, 1973. A correlation of the Pre-Cambrian rocks in the British Isles. Geological Society of London Special Report No 6. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable