86 



to the north-east. The southern escarpment is less frequently 

 concealed than the northern one. Though no actual contacts 

 were observed, yet it is highly probable that Palfeozoic rocks 

 underlie this Cretaceous bjisin. 



After leaving Mount Squires, a series of quartzite hills was 

 passed, being the continuation of the Townsend Ridges, which 

 could be dimly seen towards west. They have steep, almost per- 

 pendicular slopes, and approximate mostly in shape to the Mar- 

 quee Hills. This formation is distinctly difi'erent to the one to 

 be mentioned later, which also consists of quartzites and sand- 

 stones, but the form of these ridges and ranges is more of the 

 Table Hill shape. 



After crossing the Townsend Ridge, the country shows for the 

 next 36 miles nothing but irregular sand-hills, alternating with 

 widespread outcroppings of travertine and chalcedony rock. 



The height of this stretch is between 1,000 and 1,200 feet 

 above sea-level. A clay-pan (Camp 38) signifies, probably, the 

 outer edge of the recent formation overlying the Devonian of the 

 Tent Hill formation of the Townsend Ridges, and also the begin- 

 ning of the Mesozoic basin, because for the next 150 rniles the 

 country, though different in its surface appearance on account of 

 the more or less abundant cover of drift-sand or gravel plains, 

 shows the same character, viz., quartzite terraces gradually 

 descending towards south. 



Between Camps 47 and 48, being about 150 miles from Camp 

 38, Tertiary formation was again met, consisting of nodular 

 limestone with carbonaceous limestone-enclosures, also chal- 

 cedony, and a deposit of calcareous clay, apparently the result of 

 mound-springs. 



On proceeding fvirthcr, another sandstone terrace was de- 

 scended, and we entered wide plains with stunted growth on 

 hard sandy soil or nodular limestone, but no outcrops of bed-rock 

 were met with tmtil between camps 53 and 54, a large dry salt 

 creek was passed, on the south shore of which Palseozoio out- 

 crops rise in clilfs of moderate height. (See fig. 8, pi. 4). 



As this was in lat. 29°, and the formation distinctly trending 

 towards B.S.E., it might be looked upon as portion of the Ooldea 

 Range. Assuming this to be so, it would be a third parallel 

 wave to the former mentioned Central Australian Archtean up- 

 heavals, extending as far as long. 124°, and rising out of the 

 secondary rocks of this region. 



Prom Camp 54 to Camp 60 (Queen Victoria Spring), for a dis- 

 tance of about 120 miles, the most wretched sand-hill country was 

 traversed. There was no outcrop of anything like a bed-rock 

 found, but only small travertine deposits. 



