Physiography of Werribee Area. 20^ 



arriveclj at from a study of the physiography of this particular 

 district. 



In this area the uplifted and dissected peneplain comj^rises 

 blocks A. and C (see Fig. 2), the Blackwood and Lerderderg- 

 ranges (A), and the Brisbane ranges (C). In the other blocks it has 

 been much more dissected or obscured by lava flows. From the- 

 summits of Mount Blackwood or of VVuid Kruirk (Blue Mountain) 

 one may get an excellent view of the typical dissected peneplain. 

 Equally as striking views may be obtained in eastern Victoria, 

 but perhaps none so diagrammatically perfect. 



The same peneplain uplifted and dissected has been recognised 

 all over this State, in the highland area. New South Wales- 

 physiographers refer to three distinct peneplains in their high- 

 lands, but it is in the nature of things that ofie — the last — must ba- 

 the dominant one at present, since in its formation all, or nearly 

 all. pre-existing topograpliic features would naturally be destroyed. 

 E. C. Andrews (ref. 3, p. 118) emphasises this fact in his paper 

 on " Erosion and its Significance," viz., that the formation of one 

 peneplain must mean the complete dismantlement of any older one, 

 assuming the work to be done in areas of practically homogeneous- 

 rocks. W. B. Scott (Introduction to Geology), also says : "In the 

 production of new topographic forms, old forms are more or less 

 completely destroyed." Since, therefore, the last peneplain is the 

 important one, and since there is no recorded proof in Victoria of 

 traces of other peneplains, it is reasonable for us to consider our 

 one peneplain alone. 



(ii.) The penejil^in as an Australian feature. — We may now push 

 our investigations outward to cover a wider tract of country, and 

 the following extracts from various writers are very suggestive of 

 the possibility, long since recognised by E. C. Andrews (ref. 1), that 

 an uplifted and dissected peneplain, perhaps the same peneplain, 

 is the basis of the upland pliysiography of every State in the 

 Commonwealth . 



Victoria. — Every local writer on physiographic and allied 

 matters recognises the existence of the dissected peneplain in this 

 State. Individual opinions from various papers will be quoted 

 fater. 



Neir South Wales. — E. C. Andrews, in connuon with all his 

 fellow woi-kers in that State, accepts the peneplain as the outstand- 

 ing fact of our physiography In refei'ence 1, p. 421, he says: 

 " Eastern Australia was a peneplain raised but little above sea 



