The BGS Lexicon of Named Rock Units — Result Details

Trelowgoed Volcanic Formation

Computer Code: TRV Preferred Map Code: TrV
Status Code: Pending Upgrade
Age range: Llanvirn Series (OE) — Caradoc Series (O4)
Lithological Description: Volcanic breccia and tuff.
Definition of Lower Boundary: Not seen.
Definition of Upper Boundary: Sharp - unconformably overlain by late Llandovery mudstones.
Thickness: c.100m
Geographical Limits: From approximately 200m west of Upper Trelowgoed Farm (SO 0845 6312) to 200m south east of Alpine Bridge (SO 0905 6313), and northwest to north of New Barn Farm (SO 0958 6213).
Parent Unit: Not Applicable (-)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Exposures alongside the River Ithon, at, and up to 100m south of, Alpine Bridge, which is 3.75 km northeast of the railway station, Llandrindod Wells. 
Davies, J R, Fletcher, C J N, Waters, R A, Wilson, D, Woodhall, D G and Zalasiewicz, J A, 1997. Geology of the country around Llanilar and Rhayader. Memoir for 1:50 000 Geological Sheets 178 and 179. 
Institute of Geological Sciences. 1977. Llandrindod Wells Ordovician Inlier. Geological Special Sheet, England and Wales. Solid Geology. 1:25 000 Series. [London: Institute of Geological Sciences.] 
1:50K maps on which the lithostratigraphical unit is found, and map code used: