angular value nevertheless were productive of great eleva- 

 tions 1 and depressions. 



By a conflict of the Australian and Malayasian earth 

 forces it is probable that the two regions of these names 

 were still more separated than they had been in late 

 Tertiary time. At the time of this uplift New Guinea and 

 Tasmania appear to have become separated in part from 

 the mainland by heavy faults, and by a much more recent 

 movement they have become well detached from Australia. 



It now remains to be seen what may be learned from the 

 facts as to the relative rapidity of this motion and its cause. 



Rate of Plateau formation and later movements— That 

 the warping movement was relatively slow is apparent from 

 the fact that strong streams such as the Lower Hawkesbury 

 were enabled to hold their own against the uplift. Its 

 liuiifiM'ons are seen however by the fact that when the 

 faulting was very decided, the streams could not keep pace 

 at all with the rate of uplift. Thus the strong Barron, 

 Tully and Johnson Rivers in North Queensland have not 

 been able to keep pace with the uplift, but have only 

 recessed the very front of the uplifted block in that region. 

 In Kosciusko the Snowy has not yet cut its canon clean 

 through the uplifted fault block, nevertheless the Snowy 

 here is a strong stream. Similarly for the Eucumbene at 

 Kiandra. The slight gorges only which notch the mono- 

 clinal fold of the eastern Blue Mountains at the points 

 where it is traversed by weak streams, evidences the youth 

 of this feature. The fact also, that the most powerful 



videne 



the relative rapidity of the uplifts. It was only at cert 



1 The Western Mountains of North America and the Alps of Eu 

 appear to be examples also of this recent vertical movement. The G 

 Arizona Plateau is a fine example of such action. 



