203 



Correlation of the Marine Tertiaries of 

 Australia, 



By Professor R. Tate and J. Dexxant, F.G.8., F.C.S., Corr. 



Memlx 



PART I., VICTORIA, 



With Special Notes ox the Eocexe Beds at Sprixg Creek 



AXD at the Mouth of the Gellibraxd River. 



[Read May 2, 1898.] 



IXTRODUCTIOX. 



During the last few years our knowledge of the marine 

 tertiaries of Australia has been considerably advanced. New 

 observers have entered the field, fresh localities have been ex- 

 plored, and, most important of all, some members of the series 

 not previously known to exist on this continent have been dis- 

 covered. The various beds, although not* yet exhaustively 

 searched, have yielded an exceedingly extensive suite of fossils, 

 quite sufficient to enable geologists to come to definite con- 

 clusions concerning their relative age. 



The marine tertiaries of the southern colonies belong to three 

 distinct epochs, and adopting Lyell's method of classifying such 

 beds, viz., by the percentage of living species they contain, the 

 terms Eocene, Miocene, and Pliocene are as applicable to them 

 as to the tertiary series of the ISTorthern Hemisphere. In 

 Europe, as is well known, a fourth subdivision, viz., the Oligocene, 

 has been intercalated between the Eocene and the Miocene, but, 

 so far, no beds are known in Australia which can be at all re- 

 garded as bridging over the gap between these two well-marked 

 groups. 



Extended observations have convinced us that not only all the 

 tertiary beds hitherto called Oligocene, but also all those classed 

 as Miocene by the Geological Survey of Victoria, must certainly 

 be referred to the Eocene. These so-called Miocene beds consist 

 usually of hard polyzoal limestones, in which, with the exception 

 of casts of echinoderms, a few lamellibranchs and brachiopods, 

 the identifiable fossils are comparatively scarce. By the early 

 geologists they were said to overlie certain arenaceous and 

 argillaceous deposits, rich in fossil remains, of supposed Oligocene 

 or Eocene age, and were therefore assigned to a younger epocli. 

 Our observations lead us to conclude that this order of deposition 



