| Computer Code: |
PRL |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Asbian Substage (CR)
— Asbian Substage (CR) |
| Lithological Description: |
Thin bedded limestone turbidites (packstones and wackestones), occurring as fining-upwards graded beds, with mudstone interbeds; local thick-bedded units of resedimented fine-grained limestone (grainstones) and isolated rolled blocks of knoll reef limestone; scattered chert nodules.The formation formed as an apron of late Asbian limestone turbidites, resedimented carbonate detritus and fallen blocks of "reef" limestone derived from the adjacent North Wales Clwyd Limestone Group platform. |
| Definition of Lower Boundary: |
Not exposed, but presumed to be a conformable contact between thicker bedded limestones (packstones and grainstones) of the underlying Llanarmon Limestone Formation and thinner bedded Prestatyn Limestone facies. |
| Definition of Upper Boundary: |
Conformable contact with interbedded mudstones and dark argillaceous limestones of the Teilia Formation. |
| Thickness: |
Over 120m |
| Geographical Limits: |
Prestatyn area of North Wales (SJ 07 81). |
| Parent Unit: |
Craven Group (CRAV)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Series of adjoining disused quarries, Prestatyn, which expose c.120m of the formation, but with the base faulted. Warren et al., 1984 |
| Reference(s): |
| Warren, P T, Price, D, Nutt, M J C and Smith, E G. 1984. Geology of the country around Rhyl and Denbigh. Memoir for 1:50 000 geological sheets 95 and 107 and parts of sheets 94 and 106. |
| Davies, J R, Wilson, D and Williamson, I T. 2004. Geology of the country around Flint. Memoir for 1:50 000 Geological Sheet 108. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
