The BGS Lexicon of Named Rock Units — Result Details

Wig Member

Computer Code: WIG Preferred Map Code: Wig
Status Code: Full
Age range: Moridunian Stage (OB) — Moridunian Stage (OB)
Lithological Description: Dark grey silty mudstone containing phosphate nodules.
Definition of Lower Boundary: Conformable on sandstones of the Wig Bach Formation.
Definition of Upper Boundary: Conformable and gradational with dark grey mudstones of the undivided Wig Bach Formation.
Thickness: 30m
Geographical Limits: Not yet recorded.
Parent Unit: Wig Bach Formation (WGB)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Wig, Aberdaron Bay. Rushton, A W A and Howells, M F. 1998. 
Reference(s):
Rushton, A W A and Howells, M F. 1998. Stratigraphical framework for the Ordovician of Snowdonia and the Lleyn Peninsula. British Geological Survey Research Report, RR/99/08. 
Gibbons W and McCarroll D. 1993. Geology of the country around Aberdaron, including Bardsey Island. Memoir of the British Geological Survey, Sheet 133 (England and Wales). (London: H.M.S.O.). 88pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E133