The BGS Lexicon of Named Rock Units — Result Details

Cardiff Group

Computer Code: CAA Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Gorstian Age (SG) — Ludfordian Age (SD)
Lithological Description: Interbedded mudstones and thin siltstones with subordinate thin sandstones and bioclastic limestones.
Definition of Lower Boundary: Drawn at the base of the Hills Gardens Formation where beds of interbedded siltstones and sandstone conformably rest upon sandstone and siltstone of the Caecastell Formation.
Definition of Upper Boundary: Drawn at the conformable upward passage of limestone of the Llanderyn Formation with mudstone, calcrete and sandstone of the Raglan Mudstone Formation.
Thickness: 155 m approx.
Geographical Limits: The immediate area around Cardiff, South Wales.
Parent Unit: Not Applicable (-)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Rumney Borehole. 
Type Section  East bank of the River Rhymney. 
Reference(s):
Holland, C H, and Richardson, J B. 1977. The British Isles. "In" Martisson, A. (Ed). The Silurian-Devonian Boundary. International Union of Geological Sciences, Series A, (Stuttgart) No.5, p.35-44. 
Waters, R A and Lawrence, D J D. 1987. Geology of the South Wales Coalfield - Part III: the country around Cardiff. Memoir of the British Geological Survey, Sheet 263. (England and Wales). 
Bassett, M G. 1974. Review of the stratigraphy of the Wenlock Series of the Welsh Borderlands and South Wales. Palaeontology, 17, 745-777. 
Holland, C H, Lawson, J D, Walmsley, V G and White, D E. 1980. Ludlow stages. Silurian Series and stages decisions concerning chronostratigraphy. Lethaia, Vol.13, p.238, 268. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E263