24 RIVER YARRA, VICTORIA 
North of Healesville the Eastern Quartzites have a general 
meridional strike, but it is of the order of N. 20° W. for six miles 
south of Healesville, and then at Killara it varies considerably. 
It is obvious that the direction of the river is closely affected by 
the strike of this series of hard beds. 
The Western Quartzites have generally a meridional strike 
north of Yarra Glen, of about N. 25° E. for some eight miles to 
the Warrandyte Gorge, and then of about N. 10° E. along the 
Brushy Creek searp. Once again the strike of the quartzites 
determines the directions of the streams. The Wurunjerri River 
impinged against the Western Quartzites (then the Wurunjerri 
Range) which deflected it southwards through Lilydale to the sea. 
The country between the Eastern and Western Quartzites has 
been considerably reduced by erosion, thus leaving them in 
relief by differential erosion. West of Yarra Glen the Western 
Quartzites form a large anticline, on each side of which are grey 
shales characterized by Plectodonta bipartita. 
North of a line connecting Yarra Glen and Healesville, the 
Eastern and Western Quartzites are largely meridional in strike, 
but south of that line they splay out. This is due to the southerly 
pitch of the synelinorium, which thus brings in the younger beds 
of the Lilydale area. 
PHYSIOGRAPHIC PROBLEM OF THE QUARTZITES 
Physiographers have discussed the problem of how the westerly 
flowing Yarra could breach the Western Quartzites and so flow on 
towards Melbourne. Keble (1918), Hills (1934) and others have 
discussed this problem. Actually the same problem applies to the 
Eastern Quartzites, for these are breached by the Yarra near 
ri Hypotheses to explain these breachings are now 
offered. 
BREACHING OF HASTERN QUARTZITES 
The Middle Yarra follows the Eastern Quartzites fox eight 
miles before breaching them near Healesville. That it should 
breach them at this particular place calls for explanation. 
The early Tertiary Wurunjerri River was confined between 
the Wurunjerri Range on the west (formed by the Western 
Quartzites) and a range on the east (formed by the Eastern 
Quartzites) which might well be called the Anti-Wurunjerri 
Range, on the analogy of Lebanon and Anti-Lebanon Mountains, 
Taurus and Anti-Taurus Mountains, and so on. This valley was 
filled with Older Basalt, and a stream developed around the 
northern margin of the flow. It appears that this stream cut back 
