PROBLEM OF THE GREAT AUSTRALIAN ARTESIAN BASIN. 163 



potential region near Hughenden is distinctly saline, using 

 that term in a purely relative sense, but its salinity be- 

 comes less further to the west and north-west ; near the 

 opposite side of the basin the proportion of common salt 

 rises again. Data concerning the Flinders Valley are 

 scanty, but at Inverleigh and at Normanton, the waters 

 (in the latter case just above bed-rock) are very high both 

 in chlorine and total solids. 



Analyses are not numerous south of Hughenden, but 

 from Aramac south-eastwards to Roma, the arrangement 

 seems to be that the waters to the north-east or intake 

 side are fresh, and that the salinity rises towards the south- 

 west. Though the supplies at Barcaldine and Blackall 

 contain only traces of chlorides, they are nevertheless high 

 in alkaline carbonates. The water from the deep bore at 

 Warbreccan is high in total solids, while that from Bimerah 

 No. 3 is said to be "highly mineralised." 



Around Chinchilla and Dalby the content both of car- 

 bonate and chloride of sodium is very high, and similar 

 conditions are found away out in the Basin to beyond St. 

 George. Low chlorine values exist about Moree, and the 

 common salt content falls to 5 grains around Ooonamble, 

 the proportion of sodic carbonate ranging from 30 to 45 

 grains. It is close to Ooonamble, and more especially on 

 its south-western side, where the purest waters have been 

 brought to the surface, often with only 2 grains of chlorides 

 and 20 to 30 of alkaline carbonates; yet isolated within 

 this region of " fresh water " is a small tract with about 

 9 and 40 - 45 grains respectively. Furthermore, cut off 

 on the north, east and south by moderately saline water, 

 extends a great tract between Ounnamulla and Thargo- 

 mindah with a chlorine content of under 5 grains per gallon. 



South of the route from Bourke to Milparinka and prob- 

 ably continuous westwards into South Australia, there 



