10 Evidences of a Glacial Epoch in Victoria 



this great difference, that cuttings are generally steep enough 

 to create the waternow required to carve them, whereas the 

 plains we have in view are inclined at very low angles, and 

 therefore are traversed only by sluggish streams. The cor- 

 rugations of this rocky surface are masked by an accumula- 

 tion of clay, sand, gravel, and boulders, and in part by inter- 

 calated lava flows. These gutters trend from the Dividing 

 Ranges at a broad angle, those to the north dipping under the 

 Murray at a depth of from 300 to 400 feet from the present 

 surface, and those to the south disappearing beneath the 

 recent alluviums which swathe the foot-hills (G.S. V., Vol. VII., 

 pp. 80, 81). These gutters are the "leads" of the miner; and 

 our present interest in them lies in discovering the means 

 which eroded them. Our choice of agencies lies between water 

 and ice, and if we incline towards the latter it is because we 

 see that these leads, traverse country which has but a slight 

 fall, and because we see that they have been filled up by 

 the " spoil" characteristic of ice action. I believe that it was 

 theice plough first, and flowing ice- water last, which furrowed 

 them and then filled them up. 



The next product of glaciation which I shall point out to 

 you is the smooth-swelling rock surface which tells of mas- 

 sive ice moving slowly across the country and planing down 

 all prominences into flowing outlines. Such contours we 

 have on a large scale — undulating, rounded hills, — a constant 

 feature of all Victorian landscapes ; but of the minor form 

 — the roche moutonnee — we have no example that I can hear 

 of in Victoria. We have to visit South Australia to secure 

 the missing link. Professor Tait has described the occur- 

 rence of dome-shaped rocks at Kaizerstuhl and Crafers, 

 two localities in that colony (P. 8. T., Vol. LXIV). 



We therefore come to the last feature of glaciation — to 

 the rubbish which has been planed and ground off; to the 

 clays, the sand-drifts, the gravel beds ; to the cemented con- 

 glomerates and the loose boulders. 



All these we have in abundance, filling up the hollows, 

 crowning the rises, terracing the mountains, and sometimes, 

 capped with basalt, standing out on the open plains all alone, 

 solitary outliers, the remnants and measure of eroded 

 plateaux. 



Before we describe the alluviums in detail it will be a 

 guide to us, in discussing their origin, if we remember the 

 characteristics of well-attested ice debris in Europe and 

 America. 



