Physiography of Werrihee Area. 213 



In his interesting Physiography of Western Australia (ref. 35), 

 Jutson describes the great Darling fault scarp, extending for 200 

 miles, as well as others of lesser importance. In South Australia 

 we have the accepted rift valley of Lake Torrens, and the definite 

 block-faulting of the Mt. Lofty ranges; while between Victoria and 

 Tasmania is the great and generally accepted sunkland of Bass 

 Strait. 



In Victoria, also, T. S. Hart, commencing with the diagrammatic 

 example of block faulting in the Grampians of the west, has proved 

 the same features to continue eastward along the Divide as far as 

 Ballarat (refs. 22, 23). It is unfortunate that the Grampians them- 

 selves have not been more closely and critically studied from the 

 physiographic viewpoint. 



Jutson (ref. 33), on carefully collected physiographic evidence, 

 has demonstrated certain faults in, the middle Yarra area, and has 

 suggested the presence of others. Morris (ref. 38), in his paper 

 on the Geology of the Lilydale area, expresses his belief that the 

 geological evidence there points to the existence of important 

 faults. 



The mining fields of the State — Ballarat, Bendigo, Steiglitz, 

 Blackwood, and Wonthaggi, etc. — show abundant faulting in their 

 detailed mine plans and sections, while to miners in our fields 

 strike faults (''Slides," etc.), and dip faults ("Cross courses'') 

 are very well known features. 



The relief of the Werribee River area has been almost wholly 

 decided by differentially uplifted blocks of country (as already men- 

 tioned), separated by well-defined scarps. Of these the two most 

 important may be called : — (a) the Rowsley or Bacchus Marsh 

 scarp, and (b) the Greendale scarp. 



The faults (demonstrated or suggested) referred to in the follow- 

 ing pages are set out in Fig. 5, where they are given alphabetical 

 symbols for simplicity of reference. They will be dealt with in the 

 following order : — 



(i.) The Rowsley or Bacchus Marsh Fault, 

 (ii.) The Greendale Fault, 

 (iii.) Minor Faults. 

 (iv.) Previously demonstrated faults, 

 (v.) Suggested fault, 

 (vi.) The Sunklands. 

 (vii.) Final conclusions as to age. 



(i.) The Roivsley, or Bacchus Marsh, Fatilt. (see a, in Fig, 5). — 

 One of the least impressive portions of the scarp which marks this 



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