Physiography of the Glenebj River. 105 



of Victoria. Evidence is gradually being accumulated which 

 appears to show that this, our chief watershed, although of very 

 great diversity in material, has yet a unity of structure. This 

 general structure is of the " Ijlock-fault type," and in this the 

 Grampians, Serra, Victoria, Black, and Dundas ranges are distinct 

 partakers (if not the suggesters of the idea).!! 



A writer on the Geography of Australia2 says: "The Pyrenees 

 may be considered as the end of the Great Dividing Range on the 

 continent." This, of course, suggests that the Pyrenees are also the 

 end of the Main Divide of Victeria. Further, the much-debated 

 uniform hachure line which marks the Divide on most maps of our 

 State usually ends about Ararat. 



As a matter of fact, this Divide, regarded as a structural feature 

 of Victoria, does not end until tlie Glenelg is reached, less than 40 

 miles from the western border (see accompanying plate). The unity 

 of structure hitherto referred to must cause the inclusion of the 

 Grampians in the Divide, as also does the fact of the division of 

 the north and south flowing drainage (see Fig. 2). The low gap at 

 Ararat, where the head waters of the IMount William creek 

 (northern) and the River Hopkins (southern) are almost without 

 any separating elevation does not militate against this, nor does 

 the similar gap west of the Victoria Range. Mr. T .S. Hart, who 

 has given many years of cai-eful study to the western highlands 

 of Victoria, has shown them to consist throughout of a series of 

 north-south ranges, with intervening north-south valleys. ^ 



The railway departments of Victoria and South Australia have 

 kindly provided sufficient reliable data of heights to allow of the 

 construction of sections from north to south throughout the area 

 here dealt with, and these clearly indicate the continuation of the 

 Main Divide right to the Glenelg. There it gently plunges below 

 the tertiary plains of the Murray estuary. 



(c) Minor Elevations. — Hills which would come under this head 

 are abundant and of great variety : — 



(i.) Low-rounded hills, wholly of coast plain material, such as 

 Mount Clay and Mount Kincaid, are residuals. The timbered 

 ranges throughout area D are mostly of this type. 



(ii.) Numerous hills in the Casterton-Wando Vale area are of soft 

 Jurassic mudstones capped by a level layer of ferruginous tertiary 



1 See T. S. Hart. " Hi^'hlands and Main Divide of Western Victoria," Proc. Roy. See. Victoria, 

 December 1907, p. 270, line 36. 



2 Commonwealth Year Book, No. 3. 1910. 



3 B.A.A.S., Melb., 1914. " The Central Hiu'hlands and Main Divide of Victoria." T. S. Hart. 



