| Computer Code: |
NYGL |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Asbian Substage (CR)
— Asbian Substage (CR) |
| Lithological Description: |
Massive, bryozoan-rich reef limestone (bafflestone/framestone). Early Asbian buildup of trepostome bryozoan rich limestones at the margin of the North Wales Dinantian carbonate platform. |
| Definition of Lower Boundary: |
Not seen, but presumed to be a contact between massive, bryozoan-rich, reef limestones and underlying well-bedded, extensively dolomitised liestones (peloidal and skeletal grainstones) of the Llanarmon Limestone Formation |
| Definition of Upper Boundary: |
Contact between "massive reef" limestones and well bedded, extensively dolomitised limestones (peloidal and skeletal grainstones) of the Llanarmon Limestone Formation. |
| Thickness: |
At least 35m |
| Geographical Limits: |
Nant-y-Gamar, Llandudno (SH 8081) |
| Parent Unit: |
Llanarmon Limestone Formation (LNML)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Quarry at Nant-y-Gamar, Llandudno, which provides a section through the upper 35m of bryozoan-rich limestones of the Member. Bancroft et al., 1988. |
| Reference(s): |
| Nichols, R A H. 1965. Petrology of a Lower Carboniferous bryozoan limestone and adjacent limestones in North Wales, Great Britain. Journal of Sedimentary Petrology, Vol.35, 887-899 |
| Bancroft, A J, Somerville, I D, and Strank, A R E. 1988. A bryozoan buildup from the Lower Carboniferous of North Wales. Lethia, Vol. 21, 51-65. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
