MioecDc Strata of the (ii/ijisdi ral Lale>i Area. 133 



Spondylus gcederopoides., would, from their solid structure, be less 

 liable to injury tlian most other species, and this, no doubt, 

 accounts for their occasional occurrence in the miocene sands as 

 fairly perfect specimens; that they came originally from the 

 limestone is undoubted, since not only did we find examples in 

 the blocks broken up, but they are also connnon fossils in 

 similar rocks on the eocene clitfs close at hand. 



The re-arrangement of materials in a junction bed is of course 

 common enough. For example, just in the nodule band at 

 Muddy Creek, both eocene and miocene fos.sils are found, the 

 latter predominating, while below it a few small miocene forms 

 pass down into the older bed, and above, .some pi'oper to this 

 transg]"ess into the younger. 



The presence of so few miocene species in the 8wan Eeach 

 section is certainly remarkable, and can only be accounted for on 

 the supposition that they were almost the only ones ever 

 deposited on that particular portion of the old miocene beach. 

 In the (jippsland miocene the distribution of species is doubtless 

 partial, but this feature is nowhere else so marked as in the 

 present section. 



That the miocene in otlier parts of the ai'ea is also underlain 

 by eocene strata may be reasonably inferred. To the north on 

 the Nicholson and Tambo Rivers, the higher ground is occupied 

 by eocene strata, which also crop out to the west at Bairnsdale, 

 and again to the east on Lake Tyers. Though they are not seen 

 between the latter locality and Swan Reach, there can be little 

 doubt that they exist at ]io great depth beneath the miocene 

 throughout the intervening distance. 



In his " Notes on the Mitchell River Division," Mr. Howitt 

 describes a set of beds which till in a deeply excavated area at the 

 contact of the Bairnsdale limestones and the Avon sandstones.^ 

 The beds here referred to overlie, as Mr. Howitt points out, 

 the Mitchell River limestones at Boggy Creek and elsewhere. 

 Tiiey are best known as the Moitun Creek beds, and consist of 

 ferruginous sandstones, etc., containing casts of marine fossils, 

 the precise age of which has not yet been concUisively decided. 

 Some hundredweights of highly fossiliferous material liave been 



1 PrOK'. Report Geol. Surv ey of Vic, No. II. 



