Mountain Ranges 0/ Gipps Land. 33 



other, but still maintaining a general direction of south east, 

 until it terminates from 12 to 14 miles south-east of the 

 siunmits of the Baw Baw. This spur di^^.de3 the waters of 

 the Aberfeldy from the Jordan, and afterwards from the 

 Thomson, until the junction of the first and last named 

 rivers. 



Throughout the- whole of these spurs the general character 

 of the rocks is clay, micaceous, and schistose slates, standing 

 in planes of stratification at gradually increasing angles, 

 until at the mount they are nearly vertical against an 

 outcrop of granite* on the summit of the mount. 



The strata around the foot of Mount Wellington I have 

 had no opportunity of inspecting, and have only once passed 

 over a slight portion of the eastern spurs of the Baw Baw ; 

 but from the outcrop of white rocks on its summit (supposed 

 to be granite) and from the general aspects of both moun- 

 tains, I believe it is quite safe for the general purposes of 

 this paper, to assume that their geological characteristics are 

 similar to those of Mount Useful. 



After a consideration of the above facts, I believe that 

 sufficient ground is afforded for concluding that the ridges 

 and sub-ridges from the plains up to the divide, may be due 

 to the upheaval of the granite from below (combined with 

 chemical action as before alluded to), and, for the reasons 

 before given, such upheaval has been very gradual 

 during this period, the higher peaks have rendered the 

 process of disintegration and denudation, by the frosts and 

 rains much more rapid, owing to the gradually breaking up of 

 the continuity of the ciTist over the summits, whilst the former 

 gentle hollows, of the undulating countiy between the peaks 

 of the ridges of the divide, would gradually be eroded into 

 deep channels by the mnter floods, each having a general 

 tendency towards the lower levels of the plains, but, 

 influenced by natural or accidental obstructions, interlacing 

 and working themselves into the winding channels, such as 

 we now find in the gullies and ravines of the district. 



As this process went on, the erosion of the gullies and high 



* The outcrop, which the author, in a cursory inspection, mistook for 

 bleached granite, proves to be quartz conglomerate. 



After the reading of this paper, Mr. Ligar, the Surveyor-General, quoted a 

 general opinion of Mr. Selwyn, that a vast plateau of tertiary, crowned with 

 basalt, had once extended above the level of our mountain ranges up to 

 Mount Kosciusko, of which traces yet exist on Mount Useful, and that this 

 fact was strongly in favour of the views expressed in this paper. — T. E. R. 



D 



