DESCRIPTIVE GEOLOGY: CRYSTALLINE AND METAMORPHIC ZONE. 253 



vour to describe briefly. The following sketch-section, fig. 51, is 



100 yards in length and represents the main points to be observed. 



In it a represents gneissose-granite, non- 



porphyritic, with lenticular-tabular foliation 

 u 



parallel to that of the other rocks and to the 



junction planes of the other rocks : b represents 

 interbandings of the gneissose-granite with a 

 dark schistose orgneissic rock: c (specimen lost 

 in transit). These interbandings are so com- 

 plete that the granite bands gradually die out 

 and towards the east become mere veins cross- 

 ing, and parallel to the foliation of the gneissic 

 rock (see also diagram, p. 76) : d is a compact 

 non-foliated trap of greenish-black colour and 

 with no veins of the granite invading it : e is 

 a schist as described, p. 58. Its foliation is 

 £> parallel to that of the other rocks: there are 

 £ some few veins of granite a in it also which 

 gradually increase in number and fineness. 

 The veins ultimately fill the rock and vary in 

 size from a thickness of 1 foot to 1 inch or less. 



Before leaving the valley of the Indus we 

 must not forget to note the recent river-gravels 

 which present some features worthy of attention. 

 The hill-sides beyond Shingri and Kotkai rise 

 steeply from the river-bed in great convex slopes 

 steepening downwards. The bottom of the 

 valley is sometimes narrow and gorge-like, 

 but sometimes it spreads out into a wide plain 

 1 to \ a mile across. The bottoms of these 

 . valleys are rilled with gravel and alluvium which 

 are spread out as terraces, or which slope down 

 as detrital fans from the mountain glens. In the 

 wide valley at Derbund, and between Shingri 



( 253 ) 



a- 



