140 R. A. WEARNE AND W. G. WOOLNOUGH. 



Gorge of New South Wales in appearance. The third stream 

 ran roughly parallel to the second, divided from it by Mount 

 Greville, and flowed through Spicer's Gap. The fourth 

 stream followed the upper valley of the Teviot, flowed 

 through Wilson's Gap, and thence along the upper course 

 of the Oondamine through the gorge known locally as 

 44 Sydney Heads." 



IV. Earth Movements,— In Oainozoic times the district 

 was reduced to a peneplain level. It was next elevated to 

 a height of about 2,000 feet, and the mature river valleys 

 referred to above were worn to base level in the volcanic 

 products. This is proved by the uniform depth of the U's 

 below the summit level. A second uplift of about 2,700 

 feet next occurred in late Oainozoic time, as proved by the 

 fact that the uniform level of the 4 air gaps ' is at the same 

 height above sea level. The comparative recency of the 

 movement is indicated by the very slight alteration in 

 form suffered by the uplifted valleys since their elevation. 



Extensive trough faulting then occurred between Indoo- 

 roopilly near Brisbane and the Main Range. The first 

 faulting probably resulted in the production of what we 

 call the Lockyer Fault Block, bounded on the west and 

 south by the Main Dividing Range, and on the east by the 

 escarpment of the Little Liverpool Range. This block is 

 traversed by four meridional ridges : — the Little Liverpool 

 Range, the Mount Mistake Range, the Hip Roof, and 

 another of unknown name, with horizontal crest lines rising 

 to a uniform level of about 2,000 feet. Immediately to the 

 east of Toowoomba this faulting carried down a portion of 

 the old mature valley about 500 feet below its original level. 

 The faulting here was somewhat complex, and this fault is 

 associated with one or more others increasing the total 

 throw. 



