146 



?«toues (white, and wliite witli red streaks), clays, and gypsum 

 beds, wliile the flint rock is always found on the summits. 

 This rock is not to be found on the principal mountain ranges 

 extending from Adelaide to Mount Babbage, on the Denison 

 Eange near the Peake, nor the Termination Hill Eange south 

 of Lake Eyre. 



The broken face of the escarpment of the table hills, over- 

 looking a salt lake 25 miles north-west of Lake Kilapaninna, 

 dis^^lays marly clays mixed with gypsum and fossil bones. The 

 fossils, which have been determined by Professor Tate, consist 

 of fish vertebra), teeth and the bony scales of crocodiles, and 

 phalanges of a gigantic marsupial of the family of the kangaroo, 

 from which it may safely be concluded that the marly clays, 

 sandstone, and gypsiferous beds of the table land country are 

 of lacustrine origin. 



The sandhill country skirts the Lake, extending from the 

 shores from ten to fifty miles, the ridges having a uniform 

 direction nearly north and south. The eastern side of the 

 ridges are more abrupt than the western side, and the flats 

 between are fi^nerally firm and clayey. The flats rise and dip 

 alternately every few miles, forming small lakes or lagoons, 

 which are filled after heavy rains, but soon dry from evaporation, 

 very little sinking into the soil, which is of a very impervious 

 nature. 



I noticed on the Kallacoopah Creek, which runs into the 

 Macumba Eiver, north-west of the lower part of the "Warburton 

 Piver, and near its junction with Lake Eyre, a table land, the 

 west side of which merged into the sand ridges, whilst the other 

 portion was cut up by numerous channels running parallel like 

 sandridges towards the creek ; the ridges between these channels, 

 which were about one hundred feet across at the top, were 

 wearing away, and the sides were covered with loose sand, and 

 had every appearance of sandhills forming. I have noticed 

 similar phenomena in other places, and cannot help attributing 

 the formation of the sandridges to the combined influences of 

 wdnd and water, and not wholly to the effects of the wind. 



During about twenty years' experience in the jSTorth I have 

 found the prevailing winds to blow from the north, north-west, 

 and south-west. 



Besides Lake Eyre there are numerous smaller lakes of very 

 similar aspect. These appear to have been formed by the col- 

 lection of water from the neighbouring country, holding salt in 

 solution. 



I have found in several instances by digging in these lakes or 

 salt plains that after passing through a layer of salt from one 

 to two inches thick a layer of mud or clay is found, next a layer 

 of salt, and again a layer of mud. 



