PRESIDENTIAL ADDRESS. 49 



direction of New Guinea, the southern shore line of Aus- 

 tralia undergoing submergence in Victoria, the southern 

 part of South Australia, and the south-western part of New 

 South Wales. This tilting from N. to S. in time started 

 the Darling, the Bogan, and Macquarie rivers etc., now 

 forming what Mr. T. G. Taylor 1 has called ' boathook 

 bends ' with the main stream. 



(3) In reference to the third unit, that of the Oloncurry 

 region ascending to the Barclay Tableland beyond Camoo- 

 weal, information as to its tectonic lines is at present very 

 meagre. As regards recent uplift, as shown by Mr. B. O. 

 Andrews, 2 the Main Divide of Queensland has been warped 

 up synchronously with the Main Divide of New South 

 Wales. Dr. Jack 3 has pointed out in an able lecture, quoted 

 by Mr. Hedley, that the Main Divide of Queensland was 

 formerly close to Brisbane, but now has been pushed west- 

 wards by the rivers draining the eastern, the steeper, slope 

 of the warp, so that it is now, at the latitude of Brisbane, 

 some 50 miles west of its former position, owing to the east- 

 ward flowing rivers having cut back their channels through 

 the hard argillites and granites, just west of Brisbane, into 

 the soft rocks of the Ipswich Coal-measures. Their progress 

 further west has been checked at Toowoomba by the great 

 sills and flows of basalt extending for some distance N.W. 

 towards the head of the Burnett River. The latter river 

 and the Dawson are fast eating their channels back through 

 the Trias-Jura, and are touching the sediments of the old 

 Cretaceous sea. The Nogoa and Belyando Rivers have 

 broken right across all the old rocks of the plateau of the 

 old Main Divide, so that now around their sources the 

 Main Divide is situated on the Upper Cretaceous, Desert 



1 Commonwealth Bureau of Meteorology, Melbourne. Physiography 

 of the Proposed Federal Capital Site at Yass-Canberra, Bulletin No.6, p. 8. 



2 This Society's Journal, Vol. xliv, pp. 420-480, 



3 Lecture Reported in Brisbane Telegraph, 22/5/94. 



D-May 3,1911. 



