The BGS Lexicon of Named Rock Units — Result Details
Llanfawr Mudstone Formation
| Computer Code: | LRM | Preferred Map Code: | LrM |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Abereiddian Stage (O2) — Caradoc Series (O4) | ||
| Lithological Description: | Grey mudstone (few interbedded tuffs). | ||
| Definition of Lower Boundary: | Faulted. | ||
| Definition of Upper Boundary: | Not seen. | ||
| Thickness: | Approximately 1000 metres. | ||
| Geographical Limits: | North limit: near Cellws Farm (SO 0745 6345). West limit: Llanfawr Quarries. South limit: near Llandrindod Hall (SO 0642 6110), and East limit: near New Barn (SO 0958 6213). | ||
| Parent Unit: | Not Applicable (-) | ||
| Previous Name(s): | Nemagraptus Gracilis Shales [Obsolete Name and Code: Use LRM]
(-1047)
Glyptograptus Teretiusculus Shales [Obsolete Name and Code: Use LRM] (-376) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Reference Section | Unnamed dingle, 1.35 km east-south-east of railway station, Llandrindod Wells. | ||
| Type Section | Llanfawr Quarries which lie 700 metre north-east of the railway station, Llandrindod Wells. | ||
| Reference(s): | |||
| Elles, G L. 1939. The stratigraphy and faunal succession in Ordovician rocks of Builth-Llandrindod inlier. Quarterly Journal of the Geological Society, Vol.95, p.383-445. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E179 | |||