102 GEOLOGY OF LOWER MESOZOIC ROCKS OF QUEENSLAND, 



marked break, and there is also generally a lithological distinc- 

 tion. The Cretaceous sea represents a transgression from the 

 north, and covered the greater portion of the Jurassic strata 

 over what is now the Great Artesian Basin, and, as shown in 

 Text-fig. 6, this transgression probably divided the Australian 

 continent in two. The present Main Divide in Queensland was 

 probably elevated, and became a land-area practically throughout 

 its whole length in Cretaceous time, and has remained essentially 

 so to the present day. On the west, the Cretaceous sea covered 

 the area of the Artesian Basin as already mentioned, while, on 

 the east, there are Cretaceous marine deposits between Mary- 

 borough and Bundaberg reaching a thickness of 1,000 feet. It 

 is impossible to determine the exact extent of these to the east. 

 The marine Cretaceous, both in western Queensland and in the 

 Maryborough district, are followed by Cretaceous freshwater 

 deposits known as the Winton Series and Burrum Series, 

 respectively. 



Lower Mesozoic Pal^eogeography of the Australasian 



Region. 



Published maps indicating the geography of the Australasian 

 region durins; Mesozoic times are fevv in number. 



Perhaps the oldest is that of Neumayr, which has been con- 

 tinually quoted and figured by later writers, including Jensen"^ 

 and Hedley.f The latter "| also prepared a map to show the 

 Queensland coast at the close of the Mesozoic era. Jensen^ has 

 published a series of maps showing the distribution of land and 

 sea in the Australian region at various periods, including one in 

 Triassic time. Recently, Schuchert|| has published a series of 

 palseogeographic maps of Oceania, including one in Triassic time, 

 and one in Cretaceous. 



The important general feature of these maps is that they show 



" Proc. Linn. Soc. N. S. Wales, 1908, xxxiii., p.507. 



t Report Aust. Assoc. Adv. Science, xii., 1909, p. 332. 



t Op. ciL, p. 333. 



§ Proc. Roy. Soc. Queensland, xxiii., Pt.2, 1912. 



II Amer. Journ. Science, xlii., 1916, p. 99. 



