BY A. B. WALKOM. 103 



a coast-line not a great distance east of the present position of 

 the eastern coast of Australia. This coast-line is the western 

 shore of a long gulf running from the south in a general meri- 

 dional direction between Australia and New Zealand. Neumayr 

 called this the Gulf of Queensland. Schuchert's map shows the 

 extension of this gulf further north to about the latitude of New 

 Caledonia, when it turns to the east and again joins the ocean. 



Evidence as to the existence, or otherwise, of this gulf is scanty. 

 Hedley* says, "According to Neumayr, a meridional crease in 

 the earth's crust produced, in Jurassic times, a gulf, which he 

 called the Gulf of Queensland, whose western shore transgressed 

 the present east Australian coast." The most important piece 

 of evidence indicating the existence of this gulf is the presence 

 of an impoverished fauna of Foraminifera and Ostracoda in the 

 upper beds of the Wianamatta Stage in New South Wales {supra, 

 p. 38). This is positive evidence of marine or estuarine condi- 

 tions in the Wianamatta Basin (probably during late Triassic 

 time). There is no evidence at all to show that this gulf trans- 

 gressed the present east coast of Australia during Jurassic time; 

 it is certain that there are no evidences of Jurassic marine 

 deposits in Eastern Australia. 



The gulf was probably more or less coincident with the present 

 position of the Thomson Trough; but whether the Thomson 

 Trough is as old as Lower Mesozoic, is difficult to determine. 



The palseogeography of the Australasian region involves a 

 consideration of the structure of the south-western Pacific resrion. 

 structural studies of this region have been made by a number of 

 geologists, including Dana, Suess, Gregory, Marshall, and 

 Schuchert. 



Marshall has pointed out that some of the earlier studies were 

 based mainly on the geographic distribution of the island-chains, 

 without much knowledge of structure. He has very rightly con- 

 tended that conclusions drawn from such distribution mav be 

 quite erroneous. 



Marshall has argued that " the real boundary of the south- 

 west Pacific passes through New Zealand, Kermadec, Tonga, 

 * Report Aust. Assoc. Adv. Science, xii., p. 331. 



