36 RIVER YARRA, VICTORIA 
Devonian lavas and altered tuffs). In Oligocene times this must 
have been a prominent and important divide. It separated the 
Port Phillip area (then a land area) from the Western Port area 
(also a land area at that time). This divide is now very much 
reduced and is breached east of Carrum. Being a palaeogeo- 
graphic feature of such size and significance, a special name for it 
is desirable. I propose that it be known as the Arthur Range, 
after Mt. Arthur. | 
The limit of this divide to the north is the termination of the 
Upper Devonian lavas at Coldstream, round which the Wurun- 
jerri River flowed (Gill, 1942). How far the divide continued 
south-westerly towards King Island cannot be determined from 
our present knowledge, but it is probable, I think, that south-west 
of Cape Schanck the Western Port pre-Older Basalt river joined 
that of the ancestral Yarra (Melbourne River). 
2) Dandenongs-Warburton Divide. A line of granodiorite and 
as MUS. : g 
granite intrusions stretches from the Dandenong Ranges to the 
Baw Baw Plateau (Fig. 2), and this determines the present 
westerly course of the Middle and Upper Yarra. In early Ter- 
tiary times the Woori Yallock Basin was in existence, and it was 
А y 2 5 s , 
from there that the Wurunjerri River flowed (Edwards, 1940 
LI . . . y LI 2 ? 
Gill, 1942). The granitic intrusions to the east of the Dandenong 
? o ә . . LI . . o 
Ranges therefore formed a divide in early Tertiar times, but 
5 q г 
probably only as far as the Warburton Ranges. The Upper Yarra 
is very young, comparatively, and one assumes that the Wurun- 
jerri River drained only the Woori Yallock Basin. 
(3) Wurunjerri Range. Later information shows that this did 
not merge into the Arthur Range as described by Keble (1918). 
The Wurunjerri River flowed between the two ranges. 
(4) Morang Divide. The granite at South Morang was the core 
of a small divide between the early Tertiary Kangaroo River and 
the Melbourne River (see Fig. 6). It is marginal also to the Newer 
Basalt flow in that area. 
(5) Mt. Gellibrand Divide. As the Morang Divide bordered 
the Melbourne River on the east so the Mt. Gellibrand Divide 
bordered it on the west. Once again a granite intrusion marks 
the line of the divide. There is some evidence to suggest that 
Older Basalt flows passed down each side of this prominence (see 
distribution in Fig. 6). Newer Basalt flows surround the Mt. 
Gellibrand intrusion, which in early Tertiary times must have 
been a prominent landmark exercising an important physio- 
graphie control. 
