PROBLEM OF THE GREAT AUSTRALIAN ARTESIAN BASIN. 141 



those in the south at Eulo, Hungerford, near Angledool^ 

 between Walgett and Oollarendabri (in which the bottom 

 sinks to as much as 2,500 feet not far away) and to the 

 north of Warren, yet the bore records indicate that this 

 topographic irregularity is probably not general, but confined 

 to certain belts representing buried chains of hills 1 (See I, 

 §1809). 



The most important feature, and one to which attention 

 had been drawn at an early date, is the broad bulge in the 

 floor (with its surface rising almost to sea-level) athwart 

 the narrowest part of the basin between Oloncurry and 

 Saxby Downs. The view too, that the artesian water 

 would have to well up from the deeper region to the south- 

 east in order to travel across this buried "spill-way" into 

 the section A, is obviously in part correct; the supplies are 

 all shallow hereabouts, while the floor drops to the north- 

 west, and is cut in the Normanton bore at a little over 

 2,000 feet below sea-level. Opinion supports Jack's view 

 of a considerable submarine leakage of artesian water in* 

 this quarter into the Gulf of Carpentaria. 



The next is the buried low ridge extending south-west- 

 wards from Oharleville by way of Ounnamulla to Hunger- 

 ford, and thence directed south-eastwards to Bourke and 

 Brewarrina ; at over half a dozen localities, indeed, does 

 granite appear at the surface (See II, pi. 29). This ridge 

 cuts the basin into two unequal parts, the lesser of which, 

 O, sinks to below 3,000 feet beneath sea-level on the New 

 South Wales-Queensland border, while primary rocks were 

 reported at 2,600 feet below sea-level on its southern 

 margin at Muckadilla ; the depth of its base on the east 

 below the Darling Downs is indeterminate, however, and 



1 Several typical sections are included in the Queensland Hydraulic 

 Engineer's Reports for 1892 and 1895, also by David, in the Federal 

 Handbook, B.A.A.S., 1914; and by Pittman in the Mineral Resources of. 

 N. S. Wales, 1901. 



