496 



ISLAND LIFE 



PART II 



Stanford's Compendium of Geography and Travel, volume 

 Aibstralasia), we shall see good reason to conclude that 

 the eastern and the western divisions of the country first 

 existed as separate islands, and only became united at a 

 comparatively recent epoch. This is indicated by an 

 enormous stretch of Cretaceous and Tertiary formations 

 extending from the Gulf of Carpentaria completely across 

 the continent to the mouth of the Murray River. During 

 the Cretaceous period, therefore, and probably throughout 

 a considerable portion of the Tertiary epoch,^ there must 

 have been a wide arm of the sea occupying this area, 

 dividing the great mass of land on the west — the true seat 

 and origin of the typical Australian flora — from a long but 

 narrow belt of land on the east, indicated by the continuous 

 mass of Secondary and Palseozoic formations already 

 referred to which extend uninterruptedly from Tasmania 

 to Cape York. Whether this formed one continuous land, 

 or was broken up into islands, cannot be positively 

 determined; but the fact that no marine Tertiary beds 

 occur in the whole of this area, renders it probable that it 

 was almost, if not quite, continuous, and that it not 

 improbably extended across to what is now New Guinea. 

 At this epoch, then (as shown in the accompanying map), 

 Australia may, not improbably, have consisted of a very 

 large and fertile western island, almost or quite extra- 

 tropical, and extending from the Silurian rocks of the Flin- 

 ders range in South Australia, to about 150 miles west of the 

 present west coast, and southward to about 350 miles south 

 of the Great Australian Bight. To the east of this, at a 

 distance of from 250 to 400 miles, extended in a north and 

 south direction a long but comparatively narrow island, 

 stretching from far south of Tasmania to New Guinea ; 

 while the crystalline and Secondary formations of central 

 North Australia probably indicate the existence of one or 

 more large islands in that direction. 



1 From an examination of the fossil corals of the South-west of Victoria, 

 Professor P. M. Duncan concludes — "that, at the time of the formation of 

 these deposits the central area of Australia was occupied by sea, having 

 open water to the north, with reefs in the neighbourhood of Java." The 

 age of these fossils is not known, but as almost all are extinct species, and 

 some are almost identical with European Pliocene and Miocene species, 

 they are supposed to belong to a corresponding period. {Journal of Geol. 

 Soc, 1870.) 



