224 ANNUAL OF SCIENTIFIC DISCOVERY. 



ably have formed the barrier between this Anglo-Germanic and 

 the Anglo-Parisian basin. 1 ' Quart. Jour. Geol. Soc., xxvi., p. 346. 



TERTIARY DEPOSITS OF AUSTRALIA. 



The following; extracts are taken from the concluding portion of 

 a paper " On the Fossil Corals (Madreporaria) of the Australian 

 Tertiary Deposits," read before the Geological Society, of London, 

 by P. Martin Duncan, F.R.S., Sec. of Geological" Society : 



" When the list of the fossil corals of the Australian tertiaries is 

 compared with that of the forms living in the Australian and New 

 Zealand seas, it becomes evident that none of the recent species 

 are represented in the Cainozoic strata. Of the 20 genera 

 now existing around Australia, out of the immediate vicinity of 

 coral reefs, only 3 had species in the tertiaries. The alliance 

 of the coral faunas of the Australian tertiaries and of the sur- 

 rounding coral seas is thus very slight; and the recent species 

 have not been found in the uppermost of the tertiaries. There 

 are 3 species common to the Australian and the European 

 Cainozoic deposits ; so that the alliance of the Australian fossil 

 fauna is as great with the European Cainozoic fauna as it is 

 with that of the corals of the tropical seas to the north-east. 



" The corals of the Australian tertiaries are very characteristic. 

 They were not reef-builders, but forms which tenanted the sea- 

 bottom, from low spring-tide mark to the depth where Polyzoa 

 abound. The species of the different beds have so great a general 

 and exact resemblance, that they do not offer evidence of any 

 great biological changes having occurred during the deposition of 

 the whole of the fossiliferous tertiary sediments. It is therefore 

 not consonant with the rules of classificatory geology to subdivide 

 the sediments into such series as Oligocene, Lower, Middle, and 

 Upper Miocene, and Pliocene, which for the most part have very 

 distinct faunas in the European area. The diagnosis of the age 

 of the tertiary deposits by the percentage system cannot as yet be 

 applied to the Australian sedimentary beds, in consequence of the 

 mollusca not having been sufficiently studied ; and the comparison 

 between the existing Australian coral fauna and that of the ter- 

 tiaries would give a much older geological age to them than is 

 warranted by the physical geology of the area. During the 

 deposition of the tertiaries there was much disturbance in the 

 currents and constant alterations in the depth of the coralliferous 

 sea, whose bottom and shores were formed by the Silurians, old 

 basalts, and carbonaceous sandstones of Victoria. The conglom- 

 erates and pebbly sandstones were of course formed during dif- 

 ferent marine conditions from those which existed during the 

 deposition of the clays and clayey sands. As the depth increased 

 during the subsidences which evidently followed every /basaltic 

 outpouring, the calcareous element mingled with the wash-down 

 from the land, and finally it increased to such an extent that it 

 encroached upon the area formerly occupied by littoral deposits, 

 and even in some places covered the rocks whose denudation had 

 produced the conglomerates. There were temporary upheavals 



