82 SUNKLANDS OF PORT PHILLIP BAY AND BASS STRAIT 
were made of this, but it apparently approximated to the dune 
limestone. In the bands of sand, and to some extent in those of the 
dune limestone, the shelly matter represented for the most part 
fragments of small bivalves. The shells were derived from a 
pre-existent bed-dune rock or some bed on the Bay Bar disinte- 
grated by wind action, or resorted by wave action following 
eustatic rise of sea level similar to the sands above the dune-rock 
on the shoals of Port Phillip (Fig. 6). 
In Bore No. 4 the first notable change in sedimentation comes 
in at 153 feet (L.W.M.), the base of the Upper Dune Series; from 
this depth to 210 feet (L.W.M.) there are marine and terrigenous 
clays intercalated with which, at 170 feet (L.W.M.) and 186 feet 
(L.W.M.) , are bands, respectively 16 feet and 17 feet 6 inches 
thick, of what the drill foreman has termed “drift,” actually 
material “drifted” in from outside the area of the Bay Bar. This 
marine and terrigenous series rests on a dune series extending 
from 210 feet (L.W.M.) to 256 feet (L.W.M.) which rests on 
heavy drift reaching to 262 feet (L.W.M.), the depth at which 
the bore stopped. 
In Bore No. 1 Wannaeue no dune rock was met with indicating 
that the Upper Dune Series is restricted to the downthrow side 
of Selwyn’s Fault. 
Bore No. 1 Paywit (Fig. 5) was put down on the Bellarine 
Peninsula on the relative upthrow side of the Bellarine Fault. It 
started (Geol.-Surv. 1923-30) in a bed of clay 13 feet thick, and 
passed into a dune series consisting mainly of dune limestones 
and sands which continued for 118 feet. It then passed through 
clays, with ironstone bands, for 14 feet and sandy and ligneous 
clays for 255 feet to a depth of 400 feet. 
The QueensclifE Bore (Fig. 5) was put down about 1860 on the 
Queensclifi Peninsula, about a mile north of Shortland Bluff. It 
reached a depth of 470 feet and according to Daintree (1861-2) 
passed through 178 feet of dune limestone which, with the 42 feet 
above it in the cliff, made a total of 220 feet. 
IV. Tideways and Channels Through Nepean Bay Bar. 
The essentials for the formation of the Nepean Bay Bar in 
its present form were : 
(a) The former existence of an open bay — ^the headwaters of 
King Bay. 
(b) Headlands at each end of the mouth of the bay ap- 
proximately in a line with the direction of the current and 
the prevailing wind; this orientation lent itself to the 
formation of spits on the leeward side of the western 
headland — the seaward extension of the limestones and 
