The Geology of the Loiver Leigh Valley. 89 



pass under the upper basalt. Where the lower basalt exists, 

 viz., for about three-fourths of the distance towards the Bluff, 

 the conglomerate is always superior to it, and in some instances 

 clearly rests upon it. The miocene, in fact, occurs in a very 

 shallow depression or rather gentle curve on the side of the hill 

 between the upper and lower flows. 



Whether at the cemetery, and also in places along the bank, 

 there is eocene limestone immediately beneath the conglomerate 

 we could not definitely decide, but, judguig from the two gully 

 sections described, we think it highly probable that such is the 

 case. The uniformly supei'ior elevation of the ironstone boulders 

 to the lower basalt is, however, so apparent that we made use of 

 them both up and down the river to trace the inner or hillside 

 outcrop of the latter rock. 



To the north of Shelford, though there is abundant ironstone, 

 we have not, so fai', noticed any fossils in it. By a rigorous 

 search fossils may perhaps yet be found there, but, even if not, 

 the persistence of the deposit, together with its similar relations 

 to the other rocks, sufficiently indicates its contemporaneous 

 origin with the fossiliferous boulders lower down the river. 

 Above a certain elevation, the blocks may become unfossiliferous 

 simply because the tide level of the miocene sea is overpassed. 



If the views here expressed are correct, it follows that 

 considerable areas in this neighbourhood which have been 

 hitherto classed as pliocene must be instead I'eferred to the 

 miocene period. Wherever ironstone occurs in the Geelong 

 district underlying basalt of corresponding age to the upper 

 flow on the Leigh there is, we think, presumptive evidence that 

 it is a miocene deposit. 



A catalogue of the fossils obtained from the miocene at Shelford 

 was given in our former paper. Similar casts have been noticed 

 in the blocks since collected. A few other species might 

 perhaps be added by taking moulds of the casts, but as their 

 miocene age is now generally admitted, the labour was regarded 

 •as unnecessary. 



We searched the eastern bank of the river south of the bridge 

 some time ago for miocene fossils. After breaking up a large 

 number of ironstone boulders, we found some casts of species, 

 identical with those previously listed, at a section (No. III.), 



