Origin of yellow sand from Tamala Limestone on the Swan Coastal Plain, Western Australia

There has been considerable debate concerning the origin of the Spearwood Dunes on the Swan Coastal Plain in Western Australia. In general, it is believed that the Spearwood Dunes are a complex of calcareous coastal dunes deposited during the Quaternary and now consist of an aeolianite core (the Tamala Limestone) plus tracts of surficial residual sand from dissolution thereof. However, in the mid-seventies a counter view was presented suggesting that the sand was not residual but was transported by aeolian processes from inland sources. At 11 sites on the Swan Coastal Plain a combination of grainsize analysis and heavy-mineral analysis was used to demonstrate that the sand of the Spearwood Dunes has evolved as a result of in situ weathering of the underlying Tamala Limestone. This supports previous work on the Swan Coastal Plain and other sandplains in Western Australia, suggesting that there has been very little long-range aeolian transport of sands during the Late Pleistocene.