BY W. N. BENSON.. 267 



of which are Barraba mudstones forming the low divide between 

 the heads of the Manilla River and Borah Creek. East of here, 

 the mudstones are sharply faulted and contorted, and may thence 

 be traced gently undulating down to the Black Mountain fault. 

 Near here is Mr. Geddes' homestead on Borah Creek, "Hobden," 

 north of which is a thick bar of dark grey argillaceous limestone. 

 .Vear here, there is also a small basalt-neck breaking through the 

 mudstone. 



South of Borali Creek, the Rocky Creek Conglomerates have 

 been traced for a few miles. Their undulation brings mudstone 

 to the surface in places west of the main conglomerate band, and 

 it is probable that the fossils, which local report states occur at 

 Rangira, are in Burindi beds in such a position. Dr. Jensen 

 recorded the possible presence of Devonian rocks on Maule's 

 Creek (31), which would probably be an inlier appearing beneath 

 an anticline of Carboniferous rocks. 



We now return to Burindi and follow the Far Western Zone 

 in the opposite direction. — North of Burindi is a mass of dolerite- 

 porphyry of the Blue Knob type, cut through by the Manilla 

 lUver, and here and there are other isolated sills of the same 

 rock. Gravels, like the Tertiary gravels near Barraba, lie 

 scattered on the tops of the small hills in the main valley, and 

 north of Tareela Creek are capped by basalt. The valley of the 

 Manilla west of the great dolerite-sill, and that of Little Creek, 

 are crossed bv several minor sills of dolerite-porphyry containing 

 large, white patches of prehnite. 



North again, the Tertiary gravel is found below the basalt of 

 the old Nandewar River. It is mostly gravel with a little clay. 

 To the west, the Kocky Creek conglomerates occur approximately 

 as shown, their position having been learned from local report 

 (Plate xix.). Their occurrence in the two sharp hills of Byar 

 and Coolah near Maule's Creek, just beyond the end of Tareela 

 Creek, is proved by the observations of Dr. Jensen (31). They 

 there consist of " massive conglomerates with interbedded sheets 

 of tuff and rhyolite (quartz-porphyry), the pebbles of the con- 

 glomerate being identical in nature with the interbedded sheets." 



North of the Nandewar Range, the conglomerates continue to 



