DETAILED DESCRIPTIONS OF ROCKS. 69 



& sill occurs running parallel with the bedding of the flows a short 

 distance above the junction with the granite. Near the boundary it 

 sometimes includes blocks torn from the rhyolites, and I found one 

 iiragment of a dark coloured schistose rock imbedded in it, probably 

 derived from the underlying schists. Close to the plane of contact the 

 granite sometimes has a foliated appearance, and this is very con- 

 spicuous in some of the veins which traverse the rhyolites. 



The large mass of hills at Kaonla village, 7 miles south-west of 

 Chanod, is entirely composed of a similar granite, traversed by thick 

 veins of a finegrained eurite. These hills furnish a good example of 

 the characteristic dome shaped weathering of the granite bosses 

 (Pis. VI, VII). 



The rhyolite of the main range near its southern end is traversed 

 by several dykes of diabase which strike across the hills in a north- 

 westerly direction. They are generally found in depressions on the 

 crest of the range, the diabase weathering more rapidly than the 

 rhyolite. A small dyke of the same kind occurs at the base of the 

 large hill at Kaonla cutting through the granite, and at the same time 

 piercing a vein of eurite which also traverses the granite 



In the isolated hill at Pati, 18 miles north-west of Chanod, an in- 

 teresting section is exposed. The lower portion of the hill on the 

 southern side is composed of sandy pebbly beds, purple and greenish 

 yellow in colour. These extend up to the foot of a precipitous 

 scarp of rhyolites which form the whole of the crest and northern 

 slope of the hill, and rest conformably upon the sandy beds, the whole 

 dipping to the north-west at about 40 degrees. In places the sandy 

 beds show distinct current or false bedding and have evidently been 

 laid down under water. At the top of these beds, at the foot of the 

 scarps, is a band containing rolled pebbles of rhyolite up to six inches 

 in diameter. The upper part of this band is highly indurated, appa- 

 rently by the heat from the overlying flow of lava. About 200 feet 

 of the sandy beds are exposed, but their base is concealed by talus, 



( 6 9 ) 



