The BGS Lexicon of Named Rock Units — Result Details
Cymerig Limestone Member
| Computer Code: | CY | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Woolstonian Substage (OS) — Woolstonian Substage (OS) | ||
| Lithological Description: | Massive or concretionary, dark blue-grey, coarsely crystalline limestone with interbedded calcareous, locally tuffaceous, mudstones. | ||
| Definition of Lower Boundary: | Conformable boundary with the calcareous tuffaceous mudstones of the Gelli-grin Calcareous Ash Formation. | ||
| Definition of Upper Boundary: | Gradational, passing conformably upwards into the calcareous tuffaceous mudstones of the Gelli-grin Calcareous Ash Formation. | ||
| Thickness: | 0-4m | ||
| Geographical Limits: | Bala and Corwen districts, North Wales. | ||
| Parent Unit: | Gelli-Grin Calcareous Ash Formation (GEL) | ||
| Previous Name(s): | Bala Limestone
(-833)
Cymerig Limestone (-834) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Quarry, 350m westsouthwest of Gelli-grin Farm. Bassett, D A, Whittington, H B and Williams, A. 1966. | ||
| Reference(s): | |||
| Bancroft, B B. 1928. On the unconformity at the base of Ashgillian in the Bala district. Geological Magazine. Vol. 65, 484-493. | |||
| Elles, G L. 1922. The Bala country: its structure and rock succession. Quarterly Journal of the Geological Society of London, Vol.78, 132-175. | |||
| Sedgwick, A. 1845. On the older Palaeozoic (Protozoic) rocks of North Wales. Quarterly Journal of the Geological Society of London. Vol.1. 5-22. | |||
| Rushton, A W A and Howells, M F. 1998. Stratigraphical framework for the Ordovician of Snowdonia and the Lleyn Peninsula. British Geological Survey Research Report, RR/99/08. | |||
| Bassett, D A, Whittington, H B, and Williams, A. 1966. The stratigraphy of the Bala district, Merionethshire. Quarterly Journal of the Geological Society of London, Vol. 122, 219-271. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E136 | |||