THE BUILDING OF EASTERN AUSTRALIA. 



By H. I. JENSEN, D.Sc. (Sydney). 



Readbefore the Royal Society of Queensland, July 29th, 1911. 



I. INTRODUCTION. 

 Scope of Paper. 



The object of this paper is not to offer the reader 

 any really new material, but rather to present the know- 

 ledge we already possess in a concise form, and to point 

 out which of the very many more or less conflicting 

 theories of earth mechanics are most capable of explain- 

 ing the facts observed in Australia. 



The books and papers referred to in the compilation 

 of these notes are so numerous that they are separately 

 entered up in Appendix I. The maps illustrating the 

 growth of Eastern Australia in geological time are based 

 on those issued by Professor David to his tectonic 

 geology class. 



It shall be my endeavour first of all to show how 

 the geography of Australia has changed during geo- 

 logical time. After these changes have been described 

 we will try to enquire what meaning can be assigned 

 to them, and what kind of earth movements produced 

 them. We will then further discuss the structural 

 unity of Eastern Australia. The Petrological Unity 

 of Eastern Australia Avill then be discussed and at the 

 same time some remarks will be made on the origin of 

 some leading Australian ore deposits. 



We shall then pass on to the treatment of faulting 

 and folding, the causes of these movements and their 

 effects on topography. The origin of some -of our most 

 important land forms and scenery will then be briefly 

 dealt with. 



