| Computer Code: |
CAA |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| 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 |
East bank of the River Rhymney. |
| Type Section |
Rumney Borehole. |
| 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. |
| 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. |
| 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). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E263
|
