Builth–Llandrindod Inlier

The inlier of Ordovician rocks between Builth Wells and Llandrindod Wells in mid Wales (Figure 8.25) represents an uplifted local basin of Llanvirn to early Caradoc rocks some 10 km to the south-east of the axis of the Tywi Lineament. It lies about mid-way between the Llanvirn outcrops of the Llandeilo area (see Fairfach Railway Cutting site report) and the Shelve area, described in Chapter 7, and differs from each of those areas — from Llandeilo in showing finer clastics deposited in a deeper, more dysaerobic environment, and from Shelve in that the chief volcanic eruptions occurred in late rather than early Abereiddian times. From the time of Murchison (1839) the area has attracted researchers, for both the spectacular volcanic rocks and the well-preserved and prolific fossil faunas.

Howey Brook

Newmead

Bach-y-graig

Llanfawr Quarry

Gwern yfed fâch, Builth Road

References