| Computer Code: |
TYS |
Preferred Map Code: |
TyS |
| Status Code: |
Full |
| Age range: |
Llandovery Epoch (SL)
— Llandovery Epoch (SL) |
| Lithological Description: |
Homogeneous pale green slates. |
| Definition of Lower Boundary: |
Interbedded with underlying grey slates of the Fron-frys Formation. |
| Definition of Upper Boundary: |
Overlain by dark grey slates of the "Denbighshire Series" (Wenlock) (Variously termed Denbigh Grits Group, Pen-y-glog Group etc). |
| Thickness: |
40 - 370m |
| Geographical Limits: |
Llangollen - Corwen area of east Wales. |
| Parent Unit: |
Not Available (!)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Ty-draw, Glyn Ceiriog. Sections on northern side of Mynydd Fron-frys. |
| Reference(s): |
| Groom, T, and Lake, P. 1908. The Bala and Llandovery rocks of Glyn Ceiriog (North Wales). Quarterly Journal of the Geological Society, Vol. 64/4, 546-595. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E121
E137
|
