204 ALEX. L. DU TOIT. 



in the direction of curtailing boring operations, of controll- 

 ing and restricting the outflow of those in existence, and 

 of preventing the underground leakage by means of water- 

 tight contacts between the casing and the sealing beds. 

 In fact Artesian water ought to be recognised as an asset 

 vested in the State, and to be conserved and used in the 

 most judicious manner. It may even become necessary for 

 the State to carry through a scheme of nationalisation of 

 all the bores in the Great Basin, and to institute a system 

 whereby the amount permitted to flow from each borehead 

 would have to be determined by a Board with State 

 control. 



XII. Conclusion. 



Any working hypothesis must take into account the 

 previous history of the Basin, its development, and the 

 processes by which the reservoir became charged ; in this 

 the generally accepted Meteoric Hypothesis fails entirely. 



The conclusions arrived at by the Author agree with 

 those of Gregory, in so far that the waters are regarded as 

 composite in character, and originating from three distinct 

 sources': — (1) residual (mesozoic), (2) plutonic, and (3) 

 rainfall of an earlier epoch (tertiary). 



Of these, the bulk of the residual water is considered as 

 having to a great extent been replaced subsequently by 

 alkaline waters, fed in at the sub-basaltic outcrops as well 

 as from below, being evolved by, or derived from, the 

 hypabyssal and plutonic masses, from which the younger 

 Tertiary basalts, alkali-trachytes, etc., were derived. Aided 

 by an escape on the west, they permeated the Jurassic 

 beds, and the reservoir became charged with waters of 

 fairly uniform composition, in which carbonate of sodium 

 predominated over chloride. On the east, the stripping off 

 of the basalt, etc., from the intake beds, accompanied by 

 the pluvial conditions in the Early Pleistocene, led to the 



