Much of the coast of SW Australia is lined with a beautiful white beach composed of both quartz and carbonate sand grains. This beach environment provides a steady source for sediment to be blown further inland by the prevailing westerly winds. However a much larger source of sediment was, until recently, available to feed the growth of the dunes - the Australian continental shelf that was exposed during the Pleistocene glaciation.
During the Pleistocene (and up to less than 8000 years ago) continental ice sheets covered much of the high latitude land surface of the Earth. The water to form these continental glaciers came from the ocean and calculations show that at glacial maximum, the sea level was depressed by up to 150 meters. This would have exposed most of the continental shelves of the world. The exposed shelf off the coast of Western Australia would have been a fertile source for broken up carbonate shell material as well as quartz sand.