i-2 s 



Victorian Main Divide, while its eastern and western scarps 

 and warps parallel the associated coasts. Inland it appears 

 also to have collapsed in terraces and senkungsfelder so as 

 to form both the "Midland Valley" and the Lake Region 

 of the Island. 



The great uplift which closed the Tertiary isolated the 

 coast from the interior. A complete modification of faunas 

 and floras resulted both by reason of the isolation and by 

 reason of the climatic changes induced by this topographic 

 revolution. The plateau was breached locally by later 

 Pleistocene erosion along a line of weakness, and a moder- 

 ate intermingling of recently isolated life types resulted. 

 III. General Topography. 



Eastern Australia may be divided into (a) The interior. 

 (b) The Highlands, the faulted and downwarped surfaces 

 and the continental shelf. (See Fig. 1.) These may again 

 he subdivided, and with the exception of the inland area, 

 the various subdivisions of this half of the continent show 

 a decided correspondence with each other. A glance at 

 Figs. 1 and 2, is sufficient to reveal the peculiar relations 

 between the various parts. For example the correspondence 

 between the Great Divide of Victoria, Bass' Strait and the 

 northern Tasmanian mountains is evident, as is also that 

 of the width of the middle Queensland coastal area with 

 the breadth of the associated continental shelf. 1 



(a) The Interior of Eastern Australia.— The eastern 

 margin of the interior corresponds approximately with the 

 trend of the coast line. The interior itself consists partly 

 of plateaus and partly of Black Soil Plains. The greater 

 portion of the plateau here in New South Wales and in the 

 southern portion of Queensland is less than 1,000 feet above 

 sea level, and is dissected by broad, shallow valleys whose 



' This fact concerning the " shelf" has also been mentioned I 



