Account of Glacial J)eposits of Bacchus Mavsli. 49 



The valley of the Myrniong Creek for some little distance 

 above its junction with the Werribee is cut through basalt 

 and sandstones and conglomerates to a depth of over (iOO feet. 

 Good sections are exposed along this valley. 



On the south side, about half a mile above the confluence 

 of the two streams, a depth of over 100 feet of a material 

 similar to that described on the Ballarat Koad is exposed. 

 It consists of a mass oi yellowish white clay, quite unstrati- 

 fied, and in texture somewhat soft on the weathered 

 surface, but much harder on being penetrated. Numerous 

 stones of all sorts and sizes, from mere grit to boulders 

 several feet in diameter, are scattered irregularly, and 

 without any trace of arrangement thioughout this clay. 

 Among these stones, the principal varieties are those . 

 occuri'ing in the cutting on the road already described. 

 Chiastolite and other varieties of slate were found, together 

 with quartz, bits of jasper, and a hard, red quartzitic sand- 

 stone. Most of these stones are sub-angular, often showing 

 one or more smoothed and flattened surfaces, while the edges 

 and ends are roughly angular ; many are will striated and 

 grooved in a characteristic manner. On some large 1)0ulders 

 lying at the base of the clift', the strisB and grooves are 

 exceptionally well developed. This deposit can be traced 

 up the valley for about a quarter of a mile above this point, 

 when it thins out, and is seen to overlie and flank the 

 sandstones through wliich the valley has been worn. It is 

 overlaid by basalt known as the newer volcanic, and assigned 

 to Pliocene age (Fig. 1). 



On the other side (north) of the Myrniong Creek, but 

 nearer its junction with the Weriibee, the glacial deposit is 

 again well shown to a depth of about ] 50 feet. It is much 

 the same as that on the opposite side of the valley, and 

 striated stones are numerous. This extends to within "100 

 yards or so from the junction of the two streams. It can be 

 traced over the brow of the valley up to about the level of 

 Mr. Brittlebank's house, about 350 feet above the Creek, and 

 about 1100 feet above the sea. It then spreads out over the 

 surface. 



It would seem evident then, that the valley now occupied 

 by the Myi-niong Creek at this point at any rate is a very 

 ancient one, and was at one time probably almost filled up 

 by this glacial conglomerate. The sandstones and conglom- 

 erates through which the valley is worn, were set down as 

 Upper Palaeozoic by the Geological Survey ; then, on the dis- 



