The BGS Lexicon of Named Rock Units — Result Details

St Non's Sandstone Formation

Computer Code: SNSS Preferred Map Code: SNn
Status Code: Pending Upgrade
Age range: Comley Series (EC) — Comley Series (EC)
Lithological Description: Dark green, buff weathering planar and cross-laminated micaceous sandstones with up to 50m of basal conglomerate.
Definition of Lower Boundary: Unconformable on Neoproterozoic volcanic and intrusive rocks.
Definition of Upper Boundary: Conformable and transitional with the overlying mudstones of the Caerfai Bay Shale Formation.
Thickness: Up to 190m (including up to 50m of basal conglomerate).
Geographical Limits: Pembrokeshire, St David's Peninsula.
Parent Unit: Caerfai Group (CIS)
Previous Name(s): St Non's Sandstone (-1191)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Wave-cut platform and cliffs at the western end of St Non's Bay. Full thickness exposed.. 
Reference(s):
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. 
Cowie, J W, Rushton, A W A and Stubblefield, C J, 1972. A correlation of Cambrian rocks in the British Isles. Special Report of the Geological Society of London, No.2, p.26. 
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. 
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.] 
Thomas, H H and Jones, O T, 1912. On the Pre-Cambrian and Cambrian rocks of Brawdy, Haycastle and Brimaston, (Pembrokeshire). Quarterly Journal of the Geological Society of London, Vol.68, 374-401. 
Williams, T G. 1934. The Precambrian and Lower Palaeozoic rocks of the eastern end of St David's Precambrian area Pembrokeshire. Quarterly Journal of the Geological Society, London, Vol.90, 32-75. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E209