1^74 Charles Fenner : 



enters from the north. This junction presents features of some 

 interest, and has often been remarked by travellers with an eye for 

 topographical features. Both the Werribee and the small tributary 

 valley are in basalt, but the tributary delays its entrance in a 

 peculiar way, running parallel to the main stream, for some little 

 •distance. A plan and section of the junction is shown in Fig. 27. 

 The bed of the Werribee is here 160 feet below the general surface 

 level of the basalt plain. This feature has been erroneously re- 

 ferred to (Vic. Handbook, B.A.A.S., 1914), as a " deserted creek 

 bed." 



An iron viaduct, 1130 feet long, here spans the Werribee, tlie 

 foundations for this structure penetrate deeply into " alternating 

 beds of sand, gravel, clay, and lignite," which underlie the basalt. 

 For the greater part of the year, the waters of the new storage reser- 

 voir at Exford now submerge the feature described in tliis para- 

 graph. 



Three miles further down stream, at Exford, the Toolern Creek 

 enters from the north, at an accordant grade. The erosion about 

 tJiis junction has given gentler slopes to the sides of the valley, and 

 three roads meet here to cross the river. Immediately above the 

 junction is the site of the Exford reservoir; from the nature of the 

 valley the stored Avater will be contained in a very long and narrow 

 dam, reaching upstream for several miles. For the remainder 

 of its course (twenty-four miles) the river receives no tributaries, 

 flowing evenly along in a young valley averaging 150 feet in 

 depth. At the town of Werribee, where the Geelong-Melbourne 

 road and railway cross tlie river, it enters a triangular area of 

 river gravels and dark-coloured alluvium, though which it cuts its 

 channel to the sea. The appearance of the mouth was roughly 

 compared with a h>urvey of fifty-five years ago; it is very slightly 

 different at tlie present day. (See Quarter Slieet 20, S.E.) Just as 

 we found rich farms at the very source of the stream, seventy-one 

 miles away, and 2400 feet liiglier, on the top O'f the Main Divide, 

 so here at the mouth the land is irrigated and cultivated to the 

 very edge of Port Phillip Bay. 



(b) The Lerderderg River. — The source of this river in the Main 

 Divide has already been described. It is close to, and at the same 

 level as, the source of the Werribee, separated therefrom by a low 

 ridge. Erosion in the cultivated land of its extreme upper 

 Teaches is rapid, and the loose chocolate soil is being fast carried 

 -away. Springs from beneath the basalt provide excellent water, 

 :and are permanent. The Lerderderg valley deepens rapidly, and 



