360 GREAT SERPENTINE BELT Oi N'EAV SOUIH WALES, Vli. 



We lia\e now to consider a second group of faults, conceriiiiig' 

 wliicli little lias yet been mentioned. These run in a direction 

 appro.ximately at right angles to the main line of strike. One is 

 thus reminded of 8uess' discussion of Haw -faults or "blatter "(20), 

 and might suggest that they were here caused by the differential 

 folding thrust exerted between the Tamworth region, buttressed by 

 the Moonbi Granite, and the Xundle region buttressed by the 

 Duncan's Creek Granite; for, in those regions, strike-faults, such 

 as occur in the Loomberah region, are not nearly so .strongly 

 marked a feature. Against this, however, is the absence of any 

 dehuite evidence as to the relative age of these faults and the 

 granite-masses, and the certainty that considerable vertical, as well 

 as horizontal, movement must have occurred along the fault-planes. 

 The dip-faults are clearly 3'ounger than the folding and strike- 

 faulting, and, though the evidence is not yet conclusive, the dis- 

 placement of the serpentine from its position on the Peel River, 

 near AVarden's (Portion !), Dungowan), to the mouth of Sheep 

 Station Creek, half a mile to the cast, may well be due to the 

 marked dip-fault which runs from Hyde's Creek to the Peel River, 

 'file dip-faulting then Avould be later than the intrusion of the 

 ultrabasic rock. Furthennore, it was concluded that the large 

 open area at the mouth of Hyde's Creek owes its origin to the 

 removal, by the ri\er, of an ui-faulted block of soft Permo-Car- 

 boniferous rocks among the harder Devonian beds (3). The 

 southern boundary of this area is marked by the above-mentioned 

 dip-fault; the northern boundary is parallel thereto, and, in all 

 probability, has been determined by a similar fault. The eastern 

 and western limits of this area are suthciently nearly parallel to 

 the main strike to suggest that they were determined, in some 

 degree, by movement along lines of strike-faulting. Hence part at 

 least of the movement along these fault-planes must have occuiTed 

 after the deposition of the Permo-Carboniferous Sandstones. This, 

 however, was perhaps posthumous movement on fault-planes first 

 formed during the late Carboniferous folding. The author's 

 removal from the State has prevented his completing the detailed 

 study of the faults around this down -thrown area. 



(Coiitiimtd oil p.-li)-'>.) 



