78 MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



that is to say the felspars have been dragged out, forced over 

 one another, and broken up and re-arranged into lenticles and 

 bands. Nevertheless they are still quite recognisable in parts, and 

 shew characteristic twinning. Of augite, the few grains remaining 

 are scarcely definite enough~for recognition. The intervening layers 

 of amorphous green material are its representative ; and they wrap 

 round it and run in sinuous lines among the other constituents of the 

 rock. The fine-grained mosaic of a clear colourless mineral, side by 

 side with the evidently crushed and broken plagioclase, is noticeable 

 as being a further stage in the development of a hornblende-schist. 

 The black titaniferous iron ore has become rolled out into long thin 

 layers and lenticles parallel to the direction of foliation. It is margin- 

 ally altered into or surrounded by a bright yellow or orange sub- 

 stance inert between crossed nicols. PL II, fig. 5, represents a slice 

 of this rock which may be called a foliated epidiorite. 



No. gf F , from the same locality — see PI. II, fig. 6. This rock frag- 

 ment gives us the last link in the chain of examples, for it is a normal 

 hornhlende-schist. The pleochroic hornblende, varying from deep 

 bluish-green to pale greenish-yellow with characteristic cleavages 

 and extinctions, could not be more manifest. The slightly elongated 

 grains have their long axes parallel to the foliation, and between 

 layers of them comes granular quartz. There is no sign of plagio- 

 clase left in the rock, although there were many broken up distinct 

 fragments of it in the last- described-rock. It is possible there may 

 be a certain amount of secondary felspar present among the clear 

 granular material, but the only grains sufficiently defined for testing 

 with convergent polarised light gave uniaxial figures. 1 The fine 

 granular material with high refractive index is most probably sphene, 

 and may be accounted for by alteration of the titaniferous iron ore, 

 of which scarcely anything is left in this rock. 



Thus, uniting the observations made on the specimens from No. 

 S7T5" to "&I s> we nave a fairly connected history of the development 

 x The large white patch in the figure of this rock with tremolite (?) crystals in it 

 seems to be a secondary felspar mosaic with convergent polarised light. It is an ex- 

 ception to the general structure of the rock. 



( 78 ) 



