94 SUNKLANDS OF PORT PHILLIP BAY AND BASS STRAIT 
That the uplift (a) was regional, is shown by the outcrops of 
Miocene and Pliocene beds of the same age as those in the 
Sorrento Bore in areas distant from Sorrento, as at Mornington, 
Grices Creek, Green Gully, Beaumaris, etc., and their existence in 
bores at Altona, South Oakleigh, and other places. The Pliocene 
samples in the Sorrento Bore below 575 feet (L.W.M.) indicate 
some depth of sea, and they had to be uplifted above sea level to 
make possible the succeeding Pleistocene phases. The Sorrento 
Bore sample marking the change over from uplift to subsidence 
is that at 575 feet (L.W.M.) . The samples between that depth 
and 265 feet (L.W.M.), representing a thickness of 310 feet, 
consist for the most part of dune-rock — ^the Lower Dune Series — 
intercalated with which are some estuarine sands and shallow 
water limestones that accumulated near sea level. 
Periods of standstill occurred at 265 feet (L.W.M.) in the 
Sorrento Bore equivalent to 262 feet (L.W.M.) in Bore No. 4, 
Wannaeue, and about 197 feet (L.W.M.) in the Sorrento Bore 
equivalent to 210 feet (L.W.M.) in the Wannaeue Bore. The fact 
that dune-rock and intercalated estuarine deposits are now a 
considerable depth below sea level is, apart from the consideration 
of eustatic adjustment, evidence of tectonic subsidence. 
VII. Lines of Movement of Sunklands 
The lines on which the Bass Strait and Port Phillip Sunklands 
have moved are referred to here as faults. Wherever they have 
been seen, in section, however, the lines of weakness are in the 
form of warps, and tilting caused by these warps has been largely 
responsible for the Sunklands. It is probable, nevertheless, that 
further afield these warps develop into faults. Beyond stating 
that the Bass Strait Sunkland sank on warps or faults coinciding 
with, on the whole, the shores of the Strait, its subsidence along 
three lines of movement are our immediate concern, viz., the 
Bellarine Fault, Selwyn’s Fault, and a hypothetical fault between 
Rosebud on the Nepean Peninsula and St. Leonards on the 
Bellarine Peninsula. 
The north-west boundary of both Sunklands (Fig. 9) is a fault 
line — the Bellarine Fault — ^which coincides in direction with a 
southern Victorian trend line exemplified by the Otway Coast. 
The south-east boundary is Selwpi’s Fault, at least in part, which 
bears S.W.b.S. and coincides with a Palaeozoic tectonic line on 
the Mornington Peninsula: it is exemplified by the fault coast 
of Port Phillip Bay between Frankston and Dromana. 
The section shown in Fig. 9 is generally across the trend of these 
lines, and ties up deep bores at Sorrento, near Cape Schanck, and 
