BY R. n. CAMBAGE. 635 



glacial period. A structural study of the mountains between 

 Kiandra and the Nandewars, points to the conclusion that, since 

 the latest uplift, there has been no tectonic movement which has 

 resulted in any general lowering of the surface throughout this 

 area, consequently no modification of temperature has been 

 effected in this manner. 



Turning next to consider the possible effects of denudation, and 

 seeing that the dissection of the mountains is still in a relatively 

 youthful stage, as evidenced by the presence of gorges, the time- 

 factor since the uplift does not seem to have been sufficiently 

 great to admit of any considerable general lowering of summits 

 by denudation such as would result in producing climatic changes. 

 There is one local exception to this, as pointed out by E. C. 

 Andrews* and by T. Griffith Taylor,! in the geologically recent 

 formation of the Goulburn River valley, or Cassilis Geocol, which 

 has resulted from the softness of the strata through which the 

 river has had to cut. Considerable denudation in this locality is 

 undeniable, though judging by the northerly and north-easterly 

 dip of the strata towards this area from the southern side, it 

 seems probable that the original site of this valley presented a 

 slightly warped surface, or syncline, and was not uplifted quite 

 as much as the New England and Blue Mountain plateaus. It 

 would seem, therefore, that there may not have been much 

 general lowering of mountain summits since the last uplift, and 

 that the cause for climatic change must be looked for elsewhere. 



It is suggested that sufficient change of climate to have 

 allowed var. Muelleri to have occurred intermittently or perhaps 

 continuously throughout the area extending from Kiandra to the 

 Nandewar Mountains, may have been provided by the latest 

 glacial period in Pleistocene time. Professor David has pointed 

 out that the evidence of Pleistocene glaciation on Mount Kosci- 

 usko shows that there was a lowering of temperature of about 

 10° Fall., and that the snow-line came down about 3,000 feet 



* "Tertiary History of New England." By E. C. Andrews, B.A. 

 Records Geological Society of N. S. Wales, Vol. 7(1903), pp. 183-187. 

 t These Proceedings, 1906, p.522. 



