The BGS Lexicon of Named Rock Units — Result Details
Pen Bwlch Tuff Member
| Computer Code: | PBT | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Pending Upgrade | ||
| Age range: | Soudleyan Substage (OY) — Soudleyan Substage (OY) | ||
| Lithological Description: | Two thin units of lapilli tuff separated locally by 5m of mudstone and siltstone. | ||
| Definition of Lower Boundary: | Conformable Member of the Teirw Siltstone Formation. | ||
| Definition of Upper Boundary: | Conformably overlain by mudstones and siltstones of the Teirw Siltstone Formation. | ||
| Thickness: | To 11m | ||
| Geographical Limits: | none recorded or not applicable | ||
| Parent Unit: | Teirw Siltstone Formation (TSI) | ||
| Previous Name(s): | Pen Bwlch Tuff Formation [Obsolete Name and Code: Use PBT]
(-2358)
Pen Bwlch Tuff [Obsolete Name and Code: Use PBT] (-1754) |
||
| 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 | |||