150 E. C. ANDREWS. 



and acid granite peaks being left. The level from 3,700 - 

 3,800 feet marked a cycle of erosion only slightly less 

 sweeping in its action, while the 3,500 — 3,600 feet level 

 left masses which are of considerable length and from one 

 to two miles in width. The cycle of erosion which produced 

 the Stannifer level (3,250 - 3,300 feet) was so sbort that it 

 accomplished very little real work in the resistant acid 

 rocks, while all work of later date has been confined to a 

 continued rejuvenescence of movement during which the 

 peneplains have been lifted vertically for several thousands 

 of feet in the neighbourhood of the Main Divide, while 

 mature valleys first and then ravine-within-ravine forms 

 have been excavated in the uplifted block or blocks. 



These acid rocks appear to form buttresses right round 

 New England. The highest land occurs mainly to the east 

 of the present Main Divide, because here the acid rocks 

 have their greatest development. In the northern half, 

 the north aud south lines of the longer granite axes form 

 a great ramp to the east. The long plateau peninsulas of 

 Guy Fawkes, Tingha, and the Barrington and Gummi Tops 

 owe their existence also to the presence of huge granitoid 

 bosses. 



It is difficult for the geographer who does not know New 

 England to credit the existence of these residuals of topo- 

 graphies older than the present plateau surface, because 

 in most extra-New England areas in New South Wales the 

 acid or tin granites are subordinate in importance. Where 

 there exists tin in abundance in Eastern Australia (with the 

 possible exception of Mount Bischoff) there will acid 

 granites also be found in abundance, and there will be found 

 these Mesozoic (and early Tertiary?) levels. 



Faults and warps of the Plateau. — The conception which 

 harmonises most with the facts of observation appears to 

 be that the main New England plateau surface was 



