The BGS Lexicon of Named Rock Units — Result Details

Lingula Flags Formation

Computer Code: LF Preferred Map Code: LF
Status Code: Pending Upgrade
Age range: St David's Series (ED) — Merioneth Series (EM)
Lithological Description: Interbedded pale siliceous and feldspathic siltstones and greenish grey to buff micaceous mudstones, locally with abundant Lingulella davisii.
Definition of Lower Boundary: Conformity and gradationally overlies mudstones of the Menevian Group.
Definition of Upper Boundary: Generally faulted, but evidence locally of angular unconformity with various lithologies of Arenig age.
Thickness: 600m+
Geographical Limits: 1:50,000 Sheet 209 (St. David's) and adjacent Sheet 210, Pembrokeshire, South Wales.
Parent Unit: Not Applicable (-)
Previous Name(s): Lingula Flags [Obsolete Name And Code: Use LF] (LFS)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Nothern end of Whitesands Bay, Pembrokeshire. Cox et al. 1930. 
Reference(s):
Rushton, A W A. 1974. The Cambrian of Wales and England, 43-121 in Holland, C H (editor), The Cambrian of the British Isles, Norden and Spitzbergen (Lower Palaeozoic rocks of the world, 2). [London: John Wiley and Son.] 
Cox, A H, Green, J F N, Jones, O T and Pringle, J. 1930. The Geology of the St David's district, Pembrokeshire. Proceedings of the Geologists' Association, Vol.41, 241-273. 
Cox, A H, Green, J F N, Jones, O T and Pringle, J. 1930. The St David's District: Report of the summer meeting 1930. Proceedings of the Geologists' Association, Vol.41, 412-438. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E210 E209