298 THE DESERT SANDSTONE. 



elevation. Leichhardt is said to have found on his descent from 

 a plateau, precipices 800 feet high, but this is now known to be 

 an error in transcribing his notes. 



"The name of Desert Sandstone is unfortunately chosen for these 

 table-hills or flat-topped ridges. Sandstone there is in abundance, 

 besides ferruginous sandstones and sandstone conglomerates, but 

 they are not always in the cliffs, or only form a portion of them. 

 Nearly all the cliffs are capped with compact magnesite or 

 carbonate of magnesia, from 10 to 40 feet in thickness, sometimes 

 ferruginous, or quite pure and white. The cliffs are made up of 

 various formations, and it is incorrect to call them Desert 

 Sandstone. Here are the proofs : — At Yam Creek, about two 

 miles south from the telegraph station, the line passes through a 

 gorge, bordered on each side by precipitous cliffs, varying in 

 height from 130 to 200 feet. The bottom of the valley is 335 

 feet above the low water level of the sea. At one place w r here I 

 ascended the cliffs they were 130 feet high, of this 90 feet was 

 granite, 10 feet waterworn quartz conglomerate, ferruginous 

 magnesian sandstone 16 feet, pure white magnesite 14 feet. Two 

 miles further the cliffs were 140 feet high; of this 80 feet was 

 granite, and 50 feet a highly ferruginous sandstone horizontally 

 stratified. At the head of the Mary the cliffs were 200 feet high, 

 30 feet of this was a fine-grained white sandstone, formed of 

 wind-blown sand, the grains under the microscope being rounded 

 and abraded like the sands of the Sahara ; above this was 

 170 feet of pure white magnesite. The valley was composed of 

 palaeozoic slates and felsites.* Other instances will be given in 

 the body of this report. 



"At the gorge at Yam Creek the table-land is a mere ridge. 

 At M'Minn's Bluff (270 feet above the plain) it is an outlier, 

 broken up into detached hills ; it is the same at Mount 

 Shoobridge. At the head of the Mary the cliffs are about 200 

 feet high, then there is an inclined plane, rising 100 feet higher 

 in six miles ; then for four or five miles an inclined plane descends 

 for 40 feet a mile, until Kek wick's Springs, on a tributary of the 

 Katherine, is reached. Again, on the heads of the Katherine, a 

 sandstone table-land was ascended to a height of 250 feet, but it 

 was a mere ridge, with a valley 50 feet deep on the east side, 

 with large springs of fresh water, giving rise to a creek. Crossing, 

 this led to an inclined plane of four miles, falling about 25 feet 

 to a mile ; this brought us to a gully, the head of Maude Creek, 

 where we were in about three miles almost on the level of the 

 Katherine, and in auriferous country again. 



* A compact mixture of quirtz and felspar without any traces of 

 crystallization. 



