RIVER YARRA, VICTORIA 23 
(a) the igneous suites surrounding much of the Woori Yallock 
basin, and 
(b) the prominence of bands of quartzitie rocks in the basement 
sedimentary series. 
FIG. 2 
Distribution of outcrops of granitie intrusive rocks and Upper Devonian lavas 
relative to the course of the River Yarra. These rocks account for the westerly 
flow of the river in its upper reaches. 
The course of the Wurunjerri River, and the extent of the 
infilling lava flows has been discussed in a previous paper (Gill, 
1942). As a direct result of the volcanic activity, the Wurunjerri 
River was blotted out, and the Yarra River developed in the north 
of this area as a stream marginal to the basalt. However, in the 
east it found a course to the east of the quartzitic Warramatte 
Hills instead of west of them as did the Wurunjerri River. 
EASTERN AND WESTERN QUARTZITES 
Reference to the map (Fig. 1) indicates how the course of the 
Middle Yarra from Killara to Healesville is closely related to the 
strike of the country rock. The hills forming the west bank of 
this part of the river are constituted of quartzites and quartzitic 
rocks of resistant character. The same beds outcrop on the other 
side of the synclinorium and form the west bank of the Yarra 
from Yarra Glen to the Warrandyte Gorge. These rocks are a 
conspicuous series in the district and give rise to notable physio- 
graphic features. I therefore suggest that they be known as the 
Eastern Quartzites and the Western Quartzites respectively. 
