90 Proceedings of the Royal Society of Victoria. 



about half a mile lower down the river than Section IV. Its 

 elevation is, however, the same, viz., abont 150 feet above datum 

 line. By examining this bank at corresponding levels other out- 

 crops of the conglomerate would no doubt be discovered. 



As before stated, the upper basalt is entirely wanting on the 

 eastern side of the river from Inverleigh right up to the escarp- 

 ment opposite Dog Island. Still the two banks are of about 

 equal height, and at first sight one is apt to think that the basalt 

 which caps the western ridge once spread as a level sheet right 

 across the gorge. A more correct conclusion, however, appears 

 to be that the stream here marks a geological boundary, and 

 that the lava, when deposited was banked up against the pre- 

 existing tertiary strata. The junction of the igneous with the 

 sedimentary rocks thus denotes the line of the most easily formed 

 drainage channel, which, by continual enlargement, has finally 

 resulted in the present wide and deep gorge of the river. 



The non-existence of basalt in the strip of country enclosed by 

 the lower courses of the Leigh River and Native Hut Creek is 

 shown on the geological map of Victoria. Immediately the 

 latter creek is crossed at Teesdale, basalt is again encountered, 

 and the two streams mentioned therefore indicate the boundaries 

 of what were probably separate lava flows, the one from the west 

 and the other from the east. 



Possibly some remnants of the lower basalt may exist on the 

 eastern side of the river south of Shelf ord, but if so, they are 

 very slight, and we judge that the miocene there rests directly 

 upon the eocene. The latter is certainly not visible just where 

 we record miocene fossils ; bub since it crops out higher up the 

 river at the bridge section, and also lower down at Farrell's, its 

 continuance under the ironstone right along the bank may be 

 reasonably inferred. 



It has been previously mentioned that, at the two eocene 

 sections just quoted, the uppermost rocks consist of ironstone in 

 boulders. We examined these, but failed to discover any signs 

 of fossils in them. Similarly, along the upper margin of the 

 eastern bank, as well as on the table-land back from the river, 

 there is abundant ironstone, in which also we have not, so far, 

 detected any organic remains. On the strength, however, of the 

 fossil-bearing boulders in their vicinity, we class the ironstones 



