Cynwyd Forest Quarry
Sometimes referred to in literature as 'Bwlch y Gaseg' and in very close proximity to the area named as such on OS Map (six-inch to the mile) 1888-1913,[1] the Cynwyd Forest Quarry is a Site of Special Scientific Interest (SSSI)[2] located aside a track within the Cynwyd Forest near Corwen , Denbighshire, North Wales. It was described by Rushton et al. (2000)[3] and exposes Late Ordovician micaceous siltstones and mudstones of the Dolhir Formation (Ashgill Series, Rawtheyan Stage) which yields a rich shelly (brachiopod) fauna. Trilobites are represented by several genera although the fauna is dominated by Gravicalymene arcuata Price, 1982.[4] Bivalves, bryozoans and various Echinodermata (Crinoids and Cystoids) are also present. Examples of most of the fossils listed below are illustrated and briefly described (or remarked upon) in "Fossils of the Upper Ordovician" by Harper and Owen (Eds.).[5]
| Site of Special Scientific Interest | |
  Location within Wales | |
| Location | Denbighshire |
|---|---|
| Grid reference | SJ 09135 39969 |
| Coordinates | 52.94938°N 3.3538238°W |
| Interest | Geology/Palaeontology |
| Area | 0.18 ha |
| Notification | 16 May 1983 |
Fossils include
- Pinnatoporella carinata (Etheridge)
- Phylloporina sp.
- Graptodictya sp.
- Leptaena sp.
- Zitteloceras costatum Teichert.
- Gravicalymene arcuata Price
- Illaenus (Parillaenus) davisii (Salter)
- Remopleurides cf. nicholsoni Reed
- Pseudospaerexochus cf. conformis (Angelin)
- Pseudospaerexochus octolobatus (McCoy)
- Calyptaulax sp.
- Tretaspis sp.
- Cupulocorona rugosa Donovan and Paul
- Regulaecystis inconstans Paul
Gallery
Cynwyd Forest Quarry - photo taken July 20, 2021.
Cynwyd Forest Quarry, 20-July-2021.
References
- "Bwlch y Gaseg - Recorded name - Historic Place Names". historicplacenames.rcahmw.gov.uk. Retrieved 24 August 2021.
- "County search of SSSIs". Countryside Council for Wales. Archived from the original on 5 March 2014. Retrieved 24 August 2012.
- RUSHTON, A. W. A., OWEN, A. W., OWENS R. M. and PRIGMORE J. K. 2000. Cambrian to Ordovician stratigraphy. Joint Nature Conservation Council Peterborough, xxi + 435 pp. [dated 1999]
- PRICE, D. 1982. Calymene quadrata King, 1923 and allied species of trilobites from the Ashgill Series of North Wales. Geological Magazine, Volume 119 , Issue 1 , January 1982, pp. 57 - 66. DOI: https://doi.org/10.1017/S0016756800025656
- HARPER, D. A. T. and OWEN, A. W. (Eds.) 1996. Fossils of the Upper Ordovician. Palaeontological Association Field Guide to Fossils Volume: 7, 312 pages, 52 plates with b/w photos; 34 b/w photos and b/w line drawings.