Coast lA/ne Formation of the Western District. 29 



The basalts of Mount Rouse have formed Port Fairy; 

 whereas the indurated tufas of Tower Hill, and the indurated 

 sand dunes of the coast, have formed Lady Bay, the lavas of 

 Mount Gavoc having been checked in flow westward at 

 Yangary Creek — a small stream marking the dividing line 

 between the products of the Tower Hill eruptions and those 

 of Mount Gavoc, which latter outflow has been further 

 checked on the south-west by the ancient sand dunes on 

 which Warrnambool is built. It is possible that the lavas 

 of Mount Rouse and Mount Gavoc may blend in the country 

 between Russell's Creek and Woolsthorpe. 



To the west of Belfast, about from twenty-five to thirty 

 miles, we come on to the outflow of lava from Mount Napier 

 and Mount Eccles — the former having had its chief outpour 

 through what is known as the Lowtli Swamps, until it joins 

 the Mount Eccles outflow near to Lake Condah and thence 

 to the sea. 



I have been informed that the overflow of water from 

 Lake Condah, at one season, disappears under a portion of 

 the basalt, and after a passage of several miles emerges 

 again in considerable streams into Darlot's Creek, which 

 latter empties into the sea near Portland Bay. 



I may mention in this place that near to Yambuk there 

 is one place where in flood-time a very considerable body of 

 water enters a cavity in the indurated limestone before 

 spoken of, and disappears, but where its exit is I never could 

 learn. 



Over nearly all the coast limestone formation there is 

 evidence of hollows existing in the limestone, because in 

 driving along there is the peculiar rumble as if passing over 

 a wooden bridge or vault. 



The indurated limestone has been either formed under 

 water or submerged subsequently ; but I think the evidence 

 of formation under the sea is reliable, for I have noted what 

 I believe to be casts of the common limpet in the rock. 



I am further inclined to believe that the outflow of the 

 lava has been at a period when the sea washed the coast 

 line of limestone blufts, to which I have before alluded, as 

 forming the northern boundary of the Tower Hill marsh, 

 and which now forms the third line inland of old sea 

 coast. The evidence of the coast lava having been sub- 

 merged to a much greater extent than at present is, I think, 

 proven by the rounded and water- worn forms of the rock 



