Chwarel Singret
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Geology & landscape
Mining / Industrial: Quarry · Geological Period: Quaternary
Landscape processes: Fluvial, Glacial
Description
Description Chwarel Singret is of special interest for an exposure through a sequence of deposits that has a major bearing on interpretations of the Quaternary history of north-east Wales. The site is located in a disused quarry, 1 km west of Gresford, in the Wrexham area. The Chwarel Singret exposure shows a thick sequence of gravel, sand, silt and till deposits. Similar deposits, but predominantly sand and gravel, cover a significant part of the Wrexham area and make up a large body of sediment that has become known as the ‘Wrexham Delta Terrace’. As the name implies, some previous workers have interpreted these sediments as deltaic in origin. Others, however, have interpreted the sediments as part of a proglacial ‘sandur’ deposited by subaerial meltwater streams in front of a retreating ice margin. The most recent interpretations suggest that the deposits at Chwarel Singret were deposited at an oscillating, Late Devensian ice margin with alluvial fans being deposited by streams emanating from the ice front. Some of these fans may have been deposited as deltas in short-lived lake basins, some may have been deposited subaerially. Intermittent tills attest to periodic re-advances of the ice front, and indicate an Irish Sea origin for the ice sheet. Variability of sediment type, both laterally and vertically in the old quarry face, indicate a period of rapidly changing environmental conditions towards the end of the last glacial stage.