More sand ripple patterns photographed as I walked across the wide expanse of sand at Broughton Bay when the tide was far out in November 2016. One of the interesting things about the sand in this location and on other beaches around the Gower Peninsula is that it hasn’t come from a gradual grinding down of the local rocks. Apparently most of it was brought down from central Wales within the ice at the base of glaciers. The ice sheets were estimated to be between 200 and 300 metres thick, and the effect of that great weight of ice sliding inexorably downhill towards the coast, crushed the underlying rocks which then became incorporated in the ice. Broken rocks were transported along with the much finer particles now seen as sand and sediments in the Loughor estuary adjacent to Broughton Bay and further out into Carmarthen Bay and the Bristol Channel. The debris was deposited when the ice began to melt and the ice sheet retreated.
This whole scenario means that the sand is not a renewable resource but a finite quantity, and it is amazing that dredgers are allowed to exploit the resource. Local people fear that the dredging activities could destroy the beaches around Gower. It is true that some beaches have seen remarkable depletion of sand after extreme weather events in recent years. So far the sand seems to have eventually returned. Studies of sediment movement in the area have shown that there are naturally occurring large scale underwater and terrestrial movements of material – this can been observed on land in the erosion of dune systems in some places together with the extensive revelation of old peat beds and drowned stumps of ancient trees hitherto hidden beneath the sand, while in others the sand accumulates and forms ever-extending intertidal sand banks.