248 Charles Fenner : 



ii. From Bald or Larkin's Hill, and from a point near Blake- 

 ville, a tongue came down in an old stream, crossing the- 

 Greendale fault north of Mt. Steiglitz. 

 iii. From Greenhills, a tongue ran down what is called Green- 

 hills Creek, a small tributary of the Korjamumnip. 

 This flow did not reach to the edge of the scarp, 

 iv. From Mt. Blackwood, a tongue came down an old river that 

 flowed midway between the present Myrniong and Kor- 

 kuperrimul — referred to later as the " ancient Myrni- 

 ong " (see Fig. 21). 

 V. From Mt. BuUengarook a long tongue came down between 

 what is now Goodman's and Pyrete (or Coimadai) 

 creeks. Thisi has been previously described (ref. 43) a-s 

 the *' ancient BuUengarook " river. (See Fig. 22.) 

 The general effect, therefore, especially on the less elevated areas, 

 was obliteration. A new series of streams was formed on this new 

 surface, twin streams were originated on the higher surfaces, old 

 and uninterrupted streams, such as the Upper Lerderderg, were 

 forced to find new courses in their lower parts. All these streams 

 were rejuvenated, since a basaltic sheet is quite analogous in effect 

 to an uplift movement. Closely following, or in the later stages of, 

 this volcanic period, however, there was a great general uplift, in 

 addition, of all the blocks in the area except the Lower Werribee 

 plains (block E). The streams were thus doubly rejuvenated, and 

 were given a scarp from, which to commence their gorge-cutting and 

 general work of denudation. 



Even on the lower plains there was a certain amount of rejuvena- 

 tion, due to the basalt sheet; thus we find the Werribee and other 

 streams now flowing in narrow young gorges averaging 100 feet in 

 depth. (Fig. 27.) It was above the scarp, however, that the most 

 severe action took place, and there we have the deeper gorges of the 

 Upper Little River, the Parwan, the Werribee, the Lerderderg, etc. 

 This gives us, broadly speaking, the effect of the newer basaltic 

 eruptions. Economically, of course, the effect of the basalt flows 

 is very great. 



IX.— Detailed Account of the Physiography. 



(a) Ranges and Hills. 

 (i.) The Main Divide. — As will be seen from Plate XL, the main 

 Divide of Victoria does not enter very largely into the area under 

 discussion. The head waters of the Werribee and of the Ler- 



