ABSTRACT OF PROCEEDINGS. XXXI. 



original surface of this tableland was a peneplain cut out of Triassic 

 Permo-Carboniferous and Carboniferous strata; this peneplain is 

 a part of the great Australian Tertiary Peneplain, and was elevated 

 to its present position at the end of the Tertiary Period ; this 

 tableland may be referred to as the Hunter River tableland. In 

 this region it has been almost completely dissected and the main 

 valleys are thoroughly mature. Followed southwards from the 

 Hunter River the altitude of the tableland gradually decreases, 

 and in the neighbourhood of Gosford it is 900 feet high, while still 

 further south at Hornsby it is under 700 feet in altitude. Followed 

 northwards from the Hunter River it maintains a general altitude 

 of 1,300 to 1,400 feet, until it reaches the foot of the great southern 

 scarp of the Barrington Tableland a few miles north of Dungog. 

 The Barrington Tableland is a great fault-block, bounded by great 

 fault escarpments on its southern and western sides. At its south- 

 western corner it reaches an altitude of 5,000 feet, but has a decided 

 tilt to the north-east. The southern escarpment of this fault-block 

 is the result of a series of step-faults with a vertical throw to the 

 south of over 3,000 feet; these step-faults strike almost due east 

 and west. The Barrington Tableland is capped by Tertiary basalt 

 and this basalt has participated in the faulting ; the faulting itself 

 would appear to have taken place at the end of the Tertiary 

 Period and during the uplifting of the tableland. Small cappings 

 of Tertiary basalt also occur on the Hunter River Tableland, 

 notably at Martin's Creek and at Mount Warrawolong, these 

 appear to be remnants of extensive Tertiary flows. The greater 

 part of the Barrington Tableland belongs to the watershed of the 

 Manning River, but its southern and western margins are drained 

 by the Hunter River and its tributaries. Those draining the 

 southern side, viz , the Allyn, Paterson, Williams, etc., following 

 very definitely the strike of the Carboniferous strata over which 

 they flow. 



Monthly Meeting, 9th August, 1916. 

 Mr. R,. H. Cambage in the Ohair. 

 Eleven members were present. 



