28 Coast Line Formation of the Western District 



triumph a piece of it which he pronounced to be flint, and 

 nothing short of an adjournment to a neighbouring chemist's 

 would convince him to the contrary. 



Inland from the coast, between four and nineteen miles 

 from Belfast to the west, this indurated limestone is very 

 prevalent, with the exception of an overflow of lava between 

 the eighth and tenth miles ; but how far it extends under the 

 lava I do not know. The limestone is water-worn, is an 

 excellent road material, and is suitable for building, and 

 makes a strong mortar. It has many of the ingredients of 

 an hydraulic lime, but Mr. Foord does not esteem it highly in 

 this latter respect. 



In use I found it to make the best mortar of any I have 

 used in the colony. 



Nearly the whole of the coast line from Warrnambool to 

 Yambuk is modified by the outflow of lava from Mount 

 Rouse, which is situated about thirty-six miles from the 

 coast northerly. 



In remote ages, when Mount Rouse was active, the whole 

 of this region must have been one of sterile desolation over 

 a great portion of its area, the lava stream extending over a 

 breadth of many miles from Mount Rouse across the Hawkes- 

 dale district, and round by the high limestone clifls of Tower 

 Hill Marsh (an ancient coast line) to the sea, spreading out 

 in a fan-like shape from the Sisters in Armstrong's Bay to 

 about four miles west of Belfast. 



The lines of demarcation of the lava-flow are tolerably 

 well defined, and leave little doubt as to its source, for on 

 the north-west, about twenty-four miles from Belfast, we 

 have at the deep Creek the Mount Rouse lava on one side 

 and ancient basalt on the other, which extends a consider- 

 able way north, dividing the outflow from Mount Rouse 

 from that of Mount Napier and Mount Eccles, to which I 

 purpose alluding presently ; whilst on the east we enter on 

 to the out-throw from Tower Hill, which is of an entirely 

 difierent character to that from an}^ of the surrounding 

 vents, namely, those of Mount Gavoc to the east (lava). 

 Mount Rouse to the north (lava), and Mount Napier and 

 Mount Eccles (largely of vesicular lava); whilst Tower Hill 

 has been wholly of ash (vesicular bluestone in a comminuted 

 state), red-hot stone (glassy in structure), in isolated showers, 

 dust, and vapour, which now forms the tufa of the neigh- 

 bourhood, 



