By H. I. JENSEN, D.SC. 198 



the earliest streams took their courses, and as elevation 

 progressed, they often worked down through the sand- 

 stones into the folded formations, w^here their tendency 

 to follow structural lines would be accelerated. 



Our inland areas not having undergone much vertical 

 movement in the Tertiary, possess very old streams, many 

 of which probably date back to the Eocene. 



The Namoi and its tributaries are very old subsequent 

 streams. The Castlereagh is younger, for its original course 

 was filled up by the volcanic pile of the Warrumbungle 

 Mountains, and the river had to wander round this group 

 in a spiral. 



Present Day Movements. 



Only a few salient points will be mentioned. C. 

 Hedley and T. G. Taylor [37] have demonstrated that 

 the east coast of Australia is in the main subsiding, as shown 

 by the existence of the Barrier Reef and numerous drowned 

 River valleys. David and Halligan [38] have proved a 

 coastal subsidence of over 100 feet in post-Tertiary times 

 for the Port Jackson, Hawkesbury and Hunter River inlets. 

 Andrews [77] has shown that a slight elevatory movement 

 followed in extremely recent times. The writer has proved 

 [13] that the coasts of Moreton Bay are being slowly 

 uplifted, and this holds true for all the coast line, from Point 

 Danger to Great Sandy Island. 



The Victorian coast line is subsiding from Cape Howe 

 to Cape Otway. That of Western Australia is undergoing 

 elevation. 



Faulting is still in progress in the regions round the 

 Gulf of St. Vincent, South Australia, as shown by frequent 

 earthquakes in that region. 



Artesian Water. 



Of all Australian geological questions, none are so 

 interesting and valuable as those connected with the origin 

 and distribution of Artesian Water. In Eastern Australia, 

 Artesian Water is confined to formations later than the 

 Permian. In Western Australia it has been obtained 

 in rocks as old as Cambrian, and large supplies exist in the 

 Carboniferous of the Gascoyne River district. 



The fact is pretty well established that one of the 

 essentials for the existence of Artesian Water is a pervious 



