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, p.546-595. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E121
E137
|