1870. | ; DUNCAN—AUSTRALIAN CORALS. 315 
gical period. The enormous range of deep-sea corals is now admitted ; 
and it is certainly very remarkable that so few of them should have 
become common to the European and Australian tertiary deposits. 
The absence of any littoral connexion between Australia and the 
tracts to the north of it during the whole of the tertiary period, and 
the remoteness of the south of its area from any great centres of fre- 
quent terrestrial oscillations, may explain the persistence of type 
which is so characteristic of a large portion of its fauna and flora*. 
This persistence was infinitely less in Europe, on account of the more 
frequent changes in the physical geology of its area, such changes 
inducing emigration of some forms, unusual competition with others, 
and occasional free scope for rapid multiplication. Hence the distant 
and comparatively quiet area of Australia was tenanted by the same 
species, whilst vast biological and geological alterations took place 
in the area which was formerly considered the type by which all 
others could be compared. 
The permanent upheaval of the central and northern area of Ans- 
tralia, the extinction of its volcanoes, and the change in its coral 
fauna were grand phenomena. Considering that a relatively identi- 
cal age is given to the great upheavals of the Alps and Himalayas, 
there is some reason for asserting that the Australian and New-Zea- 
landic upheaval was more or less synchronous with them, with the 
closure of the Isthmus of Panama, and with the depression of the 
areas on either side of the American continent. 
The denudation which occurred during the upheaval of the Aus- 
tralian area was enormous, and it is to be estimated by the extent of 
the unfossiliferous deposits which cover the fossiliferous marine Ter- 
tiaries. There are no proofs of any glacial phenomena in Australia ; 
and subaerial denudation probably went on during the whole of 
that vast period, and has continued. The whole of the paying gold- 
drifts were formed after the deposition of the marine fossiliferous 
strata ; and thus the sandy ferruginous clays, coarse pebble-grits, and 
hard ironstone cements and conglomerates, together with the lava- 
plains to the north of Cape Otway, are younger than the Mount- 
Gambier polyzoan limestones. Above these latter deposits are great 
beds of blown sand, dunes, lacustrine formations, raised beaches, and 
estuarine deposits. There are some lignites, shelly and siliceous 
sands, and volcanic ashes between these two series, which attain the 
height of 130 feet at the mouth of the river Gellibrand. 
These remarks will have prepared us for a condemnation of the 
terminology usually employed by Australian geologists. I would 
suggest that the word Tertiary should be only used relatively in 
Australian geology, and that the strata (so ably mapped by the sur- 
veyors) which are above the carbonaceous sandstones should be 
called Cainozoic. The term Lower Cainozoic would refer to all the 
deposits beneath the Mount-Gambier series, the Middle to that de- 
posit, and the Upper to all above. 
It would be as well not to establish a too local terminology ; for 
* The islands of Papua and to the south of the Straits of Bali were probably 
connected with Australia at this time. 
7 2 
had 
