Computer Code: |
PEPL |
Preferred Map Code: |
notEntered |
Status Code: |
Pending Upgrade |
Age range: |
Soudleyan Substage (OY)
— Soudleyan Substage (OY) |
Lithological Description: |
Mudstones and interbedded thinly laminated, ripple-marked siltstones and sandstones. |
Definition of Lower Boundary: |
Conformable passage from underlying Cwm Clwyd Tuff Formation, the boundary being taken at the base of the epiclastic sandstones and mudstones that overlie the highest tuff of the latter formation. |
Definition of Upper Boundary: |
Conformable upward passage from mudstones and siltstones into flaggy volcaniclastic sandstones of the Swch Gorge Tuff Formation. |
Thickness: |
150 to 350m |
Geographical Limits: |
none recorded or not applicable
|
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: |
E136
E120
|