5. North Western Dunefields and Plains (DP)
5.1 Calcareous dunefields
This unit consists of small areas to the south of Walpeup and between Underbool and Cowangie. The erosion hazard is high on the dunes and on the sandy upper western slopes of the north east - south west ridges. North east - south west ridges about 2 – 10 km long, 1 km across and less than 5 m high have received scant attention being confused with strandline ridges. They occur in parts of the Raak, Tyrell and Noora depressions at variable density. They are prominent near some groundwater depressions in the Raak and Tyrrell basins. Soil profiles have been seen only in a few road and rail cuttings. The core of the ridges observed was a mottled red-grey clay, suggesting early Pleistocene weathering. These clays are overlain by calcareous loamy sandy layers of the Woorinen Formation and are frequently fashioned into east - west dunes |