SUNKLANDS OF PORT PHILLIP BAY AND BASS STRAIT 101 
depressions appear along its valley at the 47-fathom and 48- 
fathom contours. About 30 miles upstream from a line joining 
Cape Otway and Cape Wickham, it flows into a tapering depres- 
sion suggestive of an estuary. 
The bathymetrical contours reveal also several confluent 
streams, some of which, joining it on the right bank, came from 
the north from the Nepean Bay Bar; others joining it on its left 
bank, came from the “tail bank” to the south-east. Certain 
valleys coming from the north head at the 35-fathom (210 feet) 
or the 38-fathom (228 feet) platforms both probably representing 
the same land surface which extends throughout the Bay Bar. 
Briefly, the erosion on the Sunklands in King Bay and Bass 
Strait belongs to the Middle Pleistocene; it occurred before the 
Upper Dune Series had accumulated, and is in no way connected 
with the Upper Pleistocene or Recent cycles which had outlets 
through the Upper Dune Series. The Upper Pleistocene Yarra 
emptied into King Bay: the Middle Pleistocene Yarra into the 
Southern Ocean. 
In the absence of Dannevig’s (1915) corrected soundings we 
must, perforce, accept his Tamar Major River as flowing north, 
north-west, and west along the present coast of Victoria. The 
Tamar Major River was, then, part of the Middle Pleistocene 
stream system and what has been referred to as the Middle 
Pleistocene Yarra, is the south-western extension of it — its lower 
reaches. If the Western Port stream of Gregory (1903), his 
Tarago River, joined it, the confluence must have been by a boat- 
hook bend, for the bathymetrical contours (Fig. 14) show that 
the Mornington Peninsula extended some ten miles to the south, 
and the Tarago valley trended to the south-east. 
The bathymetrical contours also show that there was a bay bar 
across Western Port Heads, and that the 21-fathom scour hole 
(Fig. 14), 3 miles W.S.W. of Point Grant, Phillip Island, was 
formed by a tideway, a relic of the Upper Pleistocene Western 
Port ebb and flow. The history of the development of Western 
Port is very similar to that of Port Phillip. 
IX. The Wannaeue and Sorrento Bores and the Stages of the 
Ice Age. 
The Pleistocene or Ice Age is represented by the core of the 
Sorrento Bore to a depth of 585 feet and its upper part by the 
Wannaeue Bore. It has been shown that the sediments and dune 
accumulations in these bores are the outcome of eustatic adjust- 
ments of sea level due to the glacial and interglacial stages during 
