g6 Victoria as a Field for Geologists. 



allied to the sloths which have succeeded it on that conti- 

 nent ; so onr own Deprotodon, by being a marsupial, seems 

 a ti-tting prototype of the Australian mammals of the present 

 epoch. I cannot see my way at all clearly as a develop- 

 mentist, but I am gi^eatly mistaken if the above-mentioned 

 fact does not tend, at some future day, to throw no incon- 

 siderable light upon the origin of special forms in creation. 



I have been thus brief in treating of the tertiary rocks, 

 not because they are devoid of interesting features, but that 

 my paper is already extended to inordinate dimensions, and 

 there is yet much to say. 



Interstratified with these last, the tertiaries, is a class of 

 rocks, the basalts, of quite another character to any yet 

 spoken of I need hardly tell you that these are certainly 

 of an igneous origin. They are of varied ages, and occupy 

 no inconsiderable or unimportant position in Victorian 

 geology. A glance at the map will show their conformation, 

 and the very wide tract of country which they cover. In. 

 fact, nearly the whole of South Western Victoria is occupied 

 by them, either as a superficial stratum, or as overspread 

 by a thin capping of tertiary deposits. 



The basalts are singularly interesting, by the light they 

 appear to throw upon the power of water to erode and eat 

 away the most indurate materials. This is especially notice- 

 able along the coast line near Cape Schanck, where high cliffs 

 of this rock are worn and fretted into shapes the most fan- 

 tastical. At Fyan's Ford, near Geelong, similar results are 

 apparent, the more remarkable that here breakers and waves 

 could have played no part, a.nd that what is witnessed is 

 simply traceable to the trifling, though continual, action of 

 a tiny stream. At Keilor, too, there is a deep and wide 

 gorge, referable to the same causes. No. 1 represents it in 

 plan and in section. 



The cliffs on each side are formed of three different layers 

 of strata, each of which must have been continuous across 

 the valley. At the base is seen the Silurian strata, much 

 contorted. On this reposes a tolerably thick bed of siliceous 

 tertiary rock (the most indurate I ever saw), and on the 

 whole is superimposed a layer of basalt. The entire cliff 

 must be over a hundred feet in thickness, yet the valley 

 bounded by it has evidently been scooped out by the action 

 of the insignificant stream of the Deep Creek, and it is 

 difficult to conceive how that stream, with the present con- 

 figuration of country round, could have been much greater 



