740 PROCEEDINGS OF SECTION F. 
50-fathom or even the 100-fathom line may be taken as marking 
the extension of the Australian continent southwards at the 
time in question. 
That the elevation and subsidence of the land has been by 
widespread and not merely local movements is shown by the 
Eocene and Miocene marine series of Victoria, South Australia, 
and Tasmania, which, although subjected to elevation, are in the 
whole, at low angles, little beyond horizontal. 
Mr. A. Montgomery, lately Government Geologist in Tasmania, 
to whom I communicated briefly the results of my researches as 
to the Victorian deep leads, most kindly favoured me with his 
views as to the evidence of movements of elevation and subsidence 
observable in Tasmania. I briefly summarise these from his 
written communications and from his published reports.* 
In early Tertiary or even late pre-Tertiary times, equivalent to 
the age of the Flemington Plaut Beds of Victoria, the northern 
part of Tasmania was relatively higher above sea-level by at 
least 270 feet than it is now. 
A. period of great basaltic extrusion covered and protected 
many of the Older Tertiary Sediments and culminated in a wide- 
spread subsidence to some 1,000 feet on the west coast and 700 
feet on the north coast of Tasmania, where, for instance, the 
Beaconsfield lead is now below sea-level.* Subsequently there 
was a re-elevation of the land during Pleiocene and more recent 
times. 
Two elevations of the land surface are here indicated, the older 
of which may be considered as being represented in Victoria by 
the position of old river valleys now filled in, but still indicated 
by flows of the “Older Volcanic.” Such an example is that 
where, near Melbourne, the vestiges of a river system may be 
traced which drained approximately the same country as that 
now traversed by the Yarra and its tributaries, the Plenty, and 
Saltwater Rivers.j Another example is afforded by the stretches 
of Older Volcanic which extend from Neerim through Western 
Gippsland, and are apparently connected with the basalts of 
Phillip Island and perhaps Cape Schanck, thus indicating a river 
where embouchure is now below sea-level. | 
These observations on both sides of Bass Strait indicate a 
probable extension of the land southwards connecting Australia 
and Tasmania, but at a time far back from the Newer Volcanic 
Era, and beyond the limit of man’s existence so far as it can be 
fixed in the present state of knowledge. 
But it may perhaps be correlated with a “second connection 
between the Australian continent and Tasmania,” which Professor 
Spencer§ considers to have existed “just at the close of the 
#* XI, p. 44, } XLU, p. 129. } xu. § LI, p. 180. 
