| Computer Code: |
TSI |
Preferred Map Code: |
TSI |
| Status Code: |
Pending Upgrade |
| Age range: |
Soudleyan Substage (OY)
— Soudleyan Substage (OY) |
| Lithological Description: |
Grey, thinly laminated to pervasively bioturbated siltstones and interbedded mudstones, with local massive, lenticular sandstones and channelised intraformational mudstone conglomerates and a localised tuff member, the Pen Bwlch Tuff. |
| Definition of Lower Boundary: |
Conformably overlies rocks of the Swch Gorge Tuff Formation (qv). |
| Definition of Upper Boundary: |
Conformably overlain by rocks of the Pandy Tuff Formation (qv). |
| Thickness: |
210 to 250m |
| Geographical Limits: |
Not defined. |
| Parent Unit: |
Not Available (!)
|
| Previous Name(s): |
Teirw Beds [Obsolete Name And Code: Use TSI]
(TWB)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| none recorded or not applicable |
| Reference(s): |
| Brenchley, P J. 1978. The Caradocian rocks of the North and West Berwyn Hills. Geological Journal, Vol. 13, 137-164. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E120
E137
|
