212 



Ijrachioi^oclsj l)ut it is doubtful whether these indicate a continua- 

 tion of the echinoderm-rock observed at sea-level nearer the 

 Point. The true explanation probably is, that there is a gradual 

 passage of the one kind of rock into the other, the changes in 

 the relative proportions of gasteropods and lamellibranchs to 

 echinoderms, brachiopods, etc., being dejDendent upon conditions 

 already alluded to. 



The base of the tertiary strata is not visible in the neighbour- 

 hood of Spring Creek. Mesozoic rocks make their appearance at 

 Point Castries, about 20 miles to the west, and continue thence 

 over a wide area. They also crop out on the north, at Mount 

 Moriac, about 12 miles distant. 



At the Eagle's ]N^est, near Airey's Inlet, strata containing 

 echinoderms and brachiopods of the same species as those from 

 Spring Creek, and therefore, also of Eocene age, are underlain by 

 the " Older Basalt " of the colony. The outcrop there is described 

 by the Survey as a black sub-columnar rock, and as probably 

 analogous to the Western Port basalt. 



Tliis basalt rests directly upon Mesozoic strata at San Remo, 

 on the eastern shore of Westerr. Port, while at Flinders, on the 

 west, it is overlain by the Eocene tertiary. The " Older Basalt" 

 is commonly called Miocene, because the strata overlying it were 

 assumed to belong to that period. Instead of such being the 

 case, they are, as we have endeavoured to prove, of Eocene age, 

 and the epoch of the basalt must be correspondingly altered. It 

 cannot be younger than Eocene, and may ultimately prove to be 

 Cretaceous. 



3. Gellibraxd. 



The deposits generally known as the " Gellibrand-beds " are, 

 nevertheless, actually situated on the coast, east and west of the 

 river's mouth. The village of Princetown, 12 miles east of Port 

 Campljell, is a convenient centre to Avork from. 



The cliffs on this part of the coast are so precipitous, that the 

 beach is accessible only in a few places. Towards Princetown 

 the slope is more gradual, but the dense undergrowth and the 

 broken character of the ground make the descent very difficult. 

 Fortunately, steps have been cut, and a rude kind of ladder 

 made by Dr. Curdie, a former settler, quite close to the fossili- 

 ferous banks, and they can be reached with comparative ease. 



The most interesting section is about three miles west of the 

 Gellibrand, and is apparently the same as that described by the 

 Survey in the report already referred to. In that report the 

 deposit is called Miocene, but in more recent publications of the 

 Survey this is altered to Oligocene. As before intimated, 

 Avherever the latter term is used, tlie Lower Tertiary or Eocene 

 beds are indicated. 



