The BGS Lexicon of Named Rock Units — Result Details

Ty-Draw Slates Formation

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
Type Area  Ty-draw, Glyn Ceiriog. Sections on northern side of Mynydd Fron-frys. 
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