SUNKLANDS OF PORT PHILLIP BAY AND BASS STRAIT 99 
where coarse sand gradually replaces the outside rock conditions. 
At the north end of the Island, the flow of waters is accentuated, 
and has cut into the western edge of the relatively shallow “tail 
bank” — an extensive bank of heavy material extending north- 
east and east far into the Strait. The channel gradually decreases 
in depth from 60 to 48 fathoms. The survey of the “Endeavour” 
showed that the shallowest portion of the channel was 44 or 45 
fathoms south of Western Port. 
Dannevig concludes that there is no support for Noetling’s 
suggestion that a barrier approximately 150 feet above the level 
of the central basin, which the “Endeavour” found ranged from 
45 to 53 fathoms, extended between King Island and Western 
Port, and consequently there is no evidence of a lake. He states : 
On the contrary, we find that a nnmber of rivers from north Tasmania 
would converge towards a centre (as indicated by Noetling), but instead 
of forming a gigantic lake they would join a magnificent river running 
to the north, north-west, and west along the present coast of Victoria, and 
ultimately enter the ocean somewhere to the east of Cape OtAvay. Into this 
river, which might suitably be named the Tamar Major, would also flow 
tributaries from the now extinct eastern and western slopes of the Ba.ss Strait 
basin, so the approximate catchment area, extending from central Tasmania, in 
the south, and the Victorian Dividing Range (or further) in the north, would 
cover more than 50,000 square miles, producing 150,000 millions of cubic feet 
of water for rainfall of only one inch. 
South-west of the Nepean Bay Bar, the floor of Bass Strait and 
King Bay (Fig. 12) between the south-westerly extensions of 
Selwyn’s and the Bellarine Faults and below the 35-38 fathom 
contours, is the submerged mature surface formed by fluviatile 
erosion of the Port Phillip Sunkland: it is a fault block, for it 
has been let dovm 100 feet from the extensive Bass Strait Sunk- 
land which had previously been lowered 170 feet. On the south- 
east side of the Port Phillip Sunkland, at an elevation of 100 feet, 
and on the relative upthrow side of Selwyn’s Fault, is the easterly 
extension of the mature surface: on the north-west side of the 
Sunkland, beyond the Bellarine Fault, is the elevated, deeply 
dissected surface of the Otway Peninsula. The elevation to the 
south-east side, the so-called “tail bank” of Dannevig (1915), is 
for its greater part the mature surface of the 35-fathom platform 
—a fossil plain on the old rocks of King Island that apparently 
extended for some distance north-easterly. As indicated by 
Dannevig (1915) the currents and tidal streams cut into this 
barrier, and the material eroded from it has been deposited some 
distance away. Although not continuous, the harrier nevertheless 
did exist as claimed by Noetling (1910), although his inference as 
