SEC. 7.] THE CHAEWAR AND KATIIOL RANGE, 193 



In the vicinity of Nambye blue and grey grits and dark shales are 



intensely cut up by intrusions of dark-grey 

 Complicated dykes. 



basaltic trap, a fresh one occurring within every 



few yards at one spot, sometimes more or less vertical, and sometimes 



inclined with the bedding of the shales. These lower Jurassic rocks are 



frequently highly altered and present on fractured surfaces a glistening 



aspect in certain positions, when the light is reflected from latent 



planes of crystalline structm-e invisible in other directions.* 



Further to the north, near Koorbya, some dark shales occur in wells 

 „ , „.,, close to the village. Below them apparently, 



Koorbya. ^^ ^j^g eastward, ascending the slopes of the hills 



which incline with the stratification to the west and south-west at 5°, are 

 light greenish-grey , ashy-looking beds, among which are some resembling 

 limonite overlying coarse red sandstone with impressions of wood. 

 Under these sandstones come conglomeratic and gravelly rusty beds, 

 with softer, compact, greenish-grey, earthy sandstone, which weathers 

 into concretionary forms and overlies more gravelly sandstones with 

 whitish flags and purple layers. Olive sandstones with black carb6nace- 

 ous (?) markings and scattered quartz grains underlie these and pass 

 down by white, red, and rusty alternations into a mass of black and 

 grey, coarse, micaceous, felted-looking shale of some 150 feet in dejsth, 

 containing only some obscure plant fragments. 



These shales abut against an intrusion of solid, dark, coarse and 

 finely-crystalline, basaltic trap, varying in width up to 150 yards. 



Northwards of this a small peak is formed of more easily weathered 

 trap, the lower portion of which is intercalated between the sandstones 



* A similar structure has been observed in some of the lower jura beds of the 

 Charwar range elsewhere, less closely associated with igneous intrusions. The dykes, &c., 

 of this country being impossible to represent in detail, a general diagrammatic indication 

 has been resorted to upon the map. 



( 193 ) 



