The BGS Lexicon of Named Rock Units — Result Details
Llanfawr Mudstone Formation
Computer Code: | LRM | Preferred Map Code: | LrM |
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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): | Glyptograptus Teretiusculus Shales [Obsolete Name and Code: Use LRM]
(-376)
Nemagraptus Gracilis Shales [Obsolete Name and Code: Use LRM] (-1047) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Section | Llanfawr Quarries which lie 700 metre north-east of the railway station, Llandrindod Wells. | ||
Reference Section | Unnamed dingle, 1.35 km east-south-east of 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 |