Account of Glacial DcpO'^iit^ of Bacchii.^ AJarslt. 47 



southern spur; (3) The South Western System, south of the 

 Main Divide and west of the Southern Spur. The Main 

 Divide, according to Murray, is a " longitudinal area of 

 Lower Palaeozoic rocks, with granite and trappean intrusions." 

 These may be overlaid by, or flanked by IJ])per Palaeozoic, 

 Mesozoic, and Tertiary deposits. 



The Bacchus Marsh district is situated about midway 

 between Melbourne and Ballarat, and thus belongs to the 

 South West Drainage System. The principal streams in 

 the locality are the Werribee and its tributaries, the 

 Myrniong and Korkui)ei'rimul Creeks and the Lerderderg 

 River. The town of Bacchus Marsh is picturesquely 

 situated in a broad extensive valley 343 feet above the 

 sea, and which has pi'obably formed the basin of an ancient 

 lake. On the one side runs the Werribee, and on the other 

 the Lerderderg, the junction of the two streams taking place 

 about a mile below the town. From Bacchus Marsh the 

 country gradually rises to the Dividing Range, only a few 

 miles distant to the north. The rising ground between 

 Bacchus Marsh and the Dividing Range is known as the 

 Pentland Hills. 



The so-called glacial conglomerates are well developed in 

 this district and numerous sections exposed to view by 

 the Creeks and various cuttings provide very favourable 

 conditions for their study. 



The first section we examined is situated on the Ballarat 

 Road, about three miles on the Ballarat side of Bacchus 

 Marsh, and is at a height of about 750 feet above the sea. 

 The deposit exposed consists of a matrix of clay of a quite 

 unstratified appearance, and of a somewhat variable con- 

 sistency. It is tough and hard in places, while in others 

 it is softer and less tenacious. The colour is an indefinite 

 patchwork of white, yellow and purple. Through this 

 matrix are scattered irregularly numerous stones of various 

 sizes and sorts, rounded and sub-angular. These stones do 

 not show the slightest trace of arrangement either in size or 

 in position. Some of the stones are waterworn, but many 

 present quite another and distinct appearance. These often 

 show one or more flattened sides, while the edges and ends 

 are frequently rough or sub-angular. Besides these peculiari- 

 ties many show striated surfaces, the striae generally running 

 in the direction of the longest axis, but several sets of striae 

 can often be distinguished. Certain kinds of stones show 

 strifb much better than others. 



