10^ 



E. 0. Teali 



including the basal beds, rhyolite, conglonieiates, sandstones (in 

 one place containing Lepidodendron), purplish shales and mud- 

 stones. The area mapped includes this pait of the road, and the 

 Hickey's Creek Basin essentially, mgst attention being given to the 

 Upper Palaeozoic rocks, and their contact with the older rocks. The 

 only other formations noted are the Silurian sandstones, phyllites 

 and shales, and a small remnant of a Kainozoic basalt flow. 



Silurian. — The usual alternation of quartzitic sandstones with 

 phyllites and sliales is found in this area, but the phyllites and 

 shales predominate over the sandstones. They are generally green- 

 ish in colour, due to a certain amount of chlorite, and are fairly 

 arenaceous. The whole series is intensely folded and frequently 

 crushed. Small quartz veins are very abundant either along joints, 

 shear planes, bedding planes, or/ fiacture lines. 



Upper Palaeozoic. — The rocks belonging to this series are identi- 

 cal in character and succession with those described in the Welling- 

 ton area, but their high angle of inclination is a striking feature. 



The prevalence of thick beds of conglomerates, and coarse pebbly 

 sandstone, and the general red colour of most of the beds, espe- 

 cially the shales, combine to form a striking contrast with the 

 Silurian rocks. The boundaries as a rule are, therefore, readily 

 traced in the field, and also certain characteristic beds within the 

 series can be easily followed for' considerable distances, and these 

 are of great assistance in working out the structure. In this way 

 the rhyolite and associated conglomerates were found in following 

 across the strike to be repeated on account of a marked synclinal 

 structure, but as the mapping shows it is not of a simple character, 

 for one limb is bent round in such a manner in the vicinity of Wal- 

 laby Hill as to bring the strike of similar beds at right angles. 

 This point is perhaps the most striking feature in this area, for 

 it forms a precipitous rocky crag rising on the eastern side of 

 Hickey's Creek. It is compossd of beds of coa,rse conglomerates dip- 

 ping at 50 degress to the N.W. and striking N.E. The beds are 

 cut through towards the southern end by a small tributary of 

 Hickey's Creek causing a rocky cleft, which isolates another rocky 

 crag of slightly lower elevation, and composed of the same con- 

 glomerate. Following these beds along the strike in a N.E. 

 direction, they soon swing round to N.N.W., and the same 

 feature is noted with regard to the underlying rhyolite and 

 basal conglomerate. The same rhyolite and conglomerate can be 

 noted on the western side of Hickey's Cre?k, dipping in the opposite 



