South Wales

Abstract

The geology of South Wales represents a broad range of time and associated strata. There are Ordovician rocks of between 495 and 443 million years of age along the northern edge of the main peninsula in the vicinity of Cardigan to New Quay and then stretching across into Wales in a south west, north east swathe towards Llandrindod Wells. Silurian rocks of between 443 and 417 million years of age are present in the north west of South Wales, reaching up in a broad swathe to North Wales. Large parts of the south east where South Wales touches England feature Devonian rocks of between 417 and 354 million years of age, which are also present on the western tip of the peninsula around Pembroke. Further east along the coast towards Llanelli and Swansea and reaching up from the Bristol Channel towards the Brecon Beacons National Park are younger Carboniferous rocks of around 354–290 million years of age and there is a small arc of Triassic strata of around 248–205 million years of age reaching across from Pyle towards Cardiff. On the coastline itself, from around Porthcawl to Penarth there is evidence of Jurassic rock formations of around 205–142 million years of age. Thus, a history of over 350 million years is reflected in the geology of this interesting south western corner of Britain.