236 HREAT SEKPEXTINE-BELT OF \E\V SOUTH WALES, vi., 



cally to a varying degree (1, Pt. iii., pp. 685-6). The mass is 

 invaded by dolerite in a few places. It pinches out to the north, 

 but may be traced by "gossany" outcrops over the hill till it 

 commences again b}^ Oakey Creek, and continues, with large but 

 varying width, to Hall's Creek. 



North of Hall's Creek, the belt becomes very wide, with a very 

 well-marked western margin of serpentine-gossan rising into the 

 prominent peak known as Red Rock. East of this is a wide 

 zone of schistose serpentine and a large amount of enstatite- 

 rock(l, Pt. iii., p. 680). East again is a zone of massive bastite- 

 serpentine, rising into a well-marked ridge, followed by more 

 foliated rocks. There seems to be a bar of serpentine striking off 

 up Hall's Creek to the north-east, but this is not certain. 



An interesting botanical point may here be noted. The 

 abundance of grass-trees {Xanthorrhcta) on the massive bastite- 

 serpentine stands in marked contrast to their comparative 

 scarcity on the foliated rock and the adjacent eastern rocks. 

 This has been noted wherever well-marked areas of massive 

 serpentine occur, and is specially marked on the Little Plain. 



In the serpentine near Hall's Creek occurred the only mass of 

 noumeaite yet recorded in New South Wales. Official analyses 

 show it to contain 13-29 per cent, of NiO, and 1'32 per cent, of 

 CoO(38). 



Northwards, gabbros commence again, very easily decomposed, 

 and forming a wide, open flat enclosed between the jasper-ridge 

 to the east, and the well-marked ridge of massive bastite-ser- 

 pentine to the west; while, beyond the western side of this, the 

 ridge plunges down steeply into the valley of Hall's Creek. This 

 open flat valley on the gabbro narrows northwards to the almost 

 deserted village of Upper Bingara, once a productive gold-mining 

 camp. This was described b}^ Anderson in 1888(12). As at 

 the Paling Yard, there is a large amount of fluxion-structure 

 among the gabbros, which are here quite coarse-grained, and 

 often highl}^ altered (1, Pt. iii., pp.684-687). The gold occurred 

 in patchy "bonanzas" in reefs in the gabbro and serpentine, and 

 in the shallow alluvium covering the valley-floor. 



