Late-Glacial history of the Brecon Beacons, South Wales

Abstract

In the uplands of the Brecon Beacons, Black Mountains, Fforest Fawr area of South Wales, small arcuate moraines and/or protalus ramparts are found below steep escarpments and in glacial cirques1–3. The freshness and distinctive morphology of many of these features have led to the suggestion that they are not a product of the late Devensian ice sheet, but may have been formed during the Loch Lomond Stadial of the Late-Glacial period (Fig. 1), the last occasion when glaciers existed in the British Isles. I present here pollen-stratigraphic evidence and radiocarbon dates which form the basis for the first Late-Glacial chronology for this area of South Wales, and which prove that the features described above developed during the Loch Lomond Stadial (approximately equivalent with the Younger Dryas of Scandinavia4–6).