76 MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



veins in the schists. A diagram of the above relationship I here 

 append (fig.4). Further examples may be found in the schistose-slate 



Fig. 4. 

 aa *= Veins of gneissose-granite intruded in dark schist. 

 cc = Trap dyke cutting across both. 



hills of the Gundgurh range and in the Tanol quartzites and Infra- 

 Trias limestone near Chooeean on the same hill range. I have never 

 found any trap dykes intrusive in any of the rock formations higher 

 than the Infra-Trias. 



I shall now proceed to describe a few of the most marked 

 varieties and passage forms of these rocks. 



No. ■£$-£, f mile north-east of Mansehruh, intrusive among the 

 gneissose-granite. A typical plagioclase-augite rock. The former 

 mineral appears in good lath-shaped sections of microtine habit, clearly 

 twinned after the albite and pericline plans, and sometimes possess- 

 ing zonal inclusions. The augite occurs in very pale straw-coloured 

 irregular grains, moulded round the lath-shaped plagioclases, and, as 

 regards the individual grains, being ophitic round the smaller felspar 

 crystals. If possesses occasional twins. It very occasionally shews 

 changes into a pale greenish decomposition product which is some- 

 times pleochroic. Titaniferous iron ore is prominent in irregular 



( 76 ) 



