BY H. I. JENSEN. 591 



also our basic rocks and the alkaline rocks; analcite and nepheline 

 basalts are by no means rare, and they are in our region generally 

 rich in titanium (e.g., the analcite basalts of the Sydney Basin). 

 An analcite dolerite, very closely related to the Prospect rock, 

 has been recently collected by me near Mumbilla, Q., where it 

 occurs over a considerable area. Further, graphic and micro- 

 graphic porphyries (diorite-monzonite-porphyries) of late Mesozoic, 

 probably Cretaceous age — in hand-specimen easily taken for 

 granite — occur abundantly in South-east Queensland, and extend, 

 according to Mr. Andrews, into New England. They are com- 

 monly called granite. 



Another feature which might well be considered petrologically 

 is that sands rich in titanium, zircons, monazite, tin, with various 

 proportions of precious metals, occur all along our coasts, and 

 can be mined with profit. The tin-bearing granites and eurites 

 from Mt. Bischoff in Tasmania right up to Herberton, North 

 Queensland, also are wonderfully alike. 



These points will serve to show that the eastern coast of Aus- 

 tralia has a totally different origin and geological history from 

 the rest of the Continent, and that it has again and again been 

 affected in its entirety by great processes. 



The alkaline rocks are those which are of immediate importance 

 to this paper. Accordingly the following remarks apply specially 

 to them. 



A. Distribution of Alkaline Rocks in Eastern Australia. 



The localities where these rocks occur and their mode of 

 occurrence has already been described. A summary of localities 

 may be here given with advantage. The more isolated masses of 

 alkaline basalt are omitted. 



1. In Tasmania : Regatta Point. 



2. In Victoria : Mount Macedon. 



2. In New South Wales : The Kiama-Jamberoo area — The 

 Canoblas — The Dubbo group — The Warrumbungles — The Nande- 

 wars — And certain alkaline trachyte dykes in the Richmond- 

 Tweed district, referred to by Mr. Carne — Also the Barrigan 



