358 GREAT SERPE?JTINE BELT OF NEW SOUTH WALES, vii., 



the lloo'l-plain level had risen at least eight i'eet durnig the life ot 

 that tree. 



Foldinu and FaidtiiKj. 



A\ e are iiu\n in a position to smnniarise the teetonic struetuie 

 of the district, as deduced from the assumptions made in our 

 stratigraphical correlations. The most ob\ious fact is a general 

 close folding- along an axis ruiniing in a direction averaging N. 22*^ 

 W.-8. 22^ E. (magnetic). The folding force came from the east, 

 and the eastern side is most affected. There is a median zone of 

 great crushing into which the serpentine.s have been injected, and 

 a western zone with a dip at first nearly vertical though predomi- 

 nantly Avesterly, decreasing in amount as we pass in that direction. 



East of this Serpentine Line, however, the strike N.22"W. is by 

 no means universal, but a more nearly meridional strike is quite 

 common, as shown by the calcareous breccia on the i^outh-west of 

 Wallab}^ Mt., which runs obliquely to the Serpentine Line, or by 

 the tuffs, etc., outcropping by the roadside in Portion 43, or l)y 

 the northern end of the serpentine mass in Cope's Creek. This 

 recalls the virgatioii of strike in the Parish of Nemingha (6, map), 

 or that in the region of Mundowey on the Namoi(2 or 7, map). 

 But superposed upon this oblique strike is the regional strike 

 shown in the great lines of shear in wliich are developed the red 

 jaspers, such as those that form tlie cliffs of AVallaby ]Mt., and 

 extend to the mouth of Cope's Creek. 



AVe concluded that the eastern mass of keratophyre, in the zone 

 west of the Serpentine Line, may have a fault along its western 

 margin concealhig the limestones, for the -most part. Another 

 ])]-()l)ably occurs along the east side of the western keratophyre. 

 Between these, the chert dips E. SS'^X. at 85° in places, and is, 

 thei-efore, slightly overfolded (see Text-fig. 2). West of the 

 limestone, the beds dip to the west, but there is doubtless a con- 

 siderable amount of repetition by strike-faulting, with, occasion- 

 ally, a reversal in dip. 



The Pyramid Hill Range structurally is a great syncline, cut by 

 one or more strike-faults. Tlie analysis of the probable folding 

 and strike-faulting thus indicates a structure comparable witli that 

 of the Tamwortli District and regions further north. 



