70 MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



crushed in any way and shews no definite foliation. Brown mica 

 occurs in tabular plates with jagged edges partly decomposed with 

 development of magnetite along the cleavage. 



Accessories present are magnetite (chiefly confined to the mica), 

 white mica, and minute garnets. 



No. jfy, a little south of Panodee near Mansehruh. This is a semi- 

 foliated variety of the gneissose-granite, non-porphyritic. In the 

 hand it is seen to be composed of quartz, white felspar, white mica and 

 schorl. Its foliation is much more distinct than that of the last speci- 

 men, though still far below the more marked examples of pressure 

 foliation. 



Under the microscope the larger felspars shew binary twins and 

 are much altered. They are doubtless orthoclase. No microcline-like 

 structure is noticeable in these crystals ; but some few smaller crystals 

 exhibit vaguely through the dusty decomposition products the re- 

 peated albite twining of plagioclase. Quartz is well represented in 

 large grains of irregular shape, giving undulose extinction over their 

 central parts, and with a border of crushed material polarising in a 

 confused mosaic. In many places the state of strain in the middle of 

 a grain, indicated by the undulose extinction, passes by a gradual 

 transition into a cracked state at the margin, with aggregate polar- 

 isation. 



The schorl is irregularly and locally developed in the rock in 

 somewhat irregular grains. The white mica is in jagged packets 

 sometimes, the risibility of the rock being due chiefly to the 

 arrangements of these in layers. 



Magnetite as an accessory appears to be only developed by the 

 composition of the schorl. 

 In this, as in all the rocks of this class, schorl is only present 

 when black mica is absent. 



No. sfy, i mile south of " D " of Doguh. This also is a semi- 

 foliated variety like the rock just described. Contains felspar, 

 ( 70 ) 



