Yol. 56.] THE GEOLOGY OF GILGIT. 349 



is traversed by the Hatu Pir Granite, and this is itself cut through 

 by dykes of the acid variety of the Hatu Pir Granite already 

 described. The epidote in the diorite is probably due to the 

 contact-action of the granite, as it is particularly abundant along 

 the line of junction, as for instance in a specimen of the diorite 

 in actual contact with a gigantic granite-dyke. 



Halfway between Gilgit and Nomal a bed of limestone, 30 feet 

 thick, occurs in a very fine-grained, slaty-looking, micaceous horn- 

 blende-schist. One of my specimens is a white crystalline 

 saccharoidal rock ; another is streaked with thin cherty and 

 siliceous bands, the latter having a micro-tessellated structure.. 

 The second specimen contains some hexagonal crystals of graphite 

 of microscopic size. 



These limestones are very pure, and contain from 80 to 92 per 

 cent, of calcium carbonate, with about 4 per cent, of magnesium 

 carbonate. They greatly resemble the Nilt-Hini beds described on 

 a subsequent page. The beds here dip inward, and suggested to 

 Capt. Roberts a synclinal fold. Suggestions regarding the age of 

 these and succeeding limestones will be made later on. 



Near Nomal a fine-grained mica-schist becomes the predomi- 

 nant rock. Whole cliffs at that locality are made up of this schist. 

 It is composed of quartz and mica, a little iron-pyrites (the latter 

 mineral is very abundant in Jutial Nalah), red ferrite, and mag- 

 netite. The mica is nearly colourless in transmitted light, and its 

 dichroism is scarcely noticeable in thin slices. Quartz-schist also 

 occurs at Nomal, and much of it is reddened with ferric oxide. 



Between Nomal and Chalt an epidotic hornblende-schist 

 is the predominant rock. It is composed of bands of hornblende 

 and epidote. The hornblende is orientated indifferently in all direc- 

 tions, and is in long lath-shaped prisms and idiomorphic octagonal 

 cross-sections, set in a quartz-mosaic matrix. The pleochroism is 

 strong : (a) brownish-green, (ft) greenish-yellow, and (c) bluish- 

 green. The hornblende- and epidote-crystals penetrate one into 

 the other, sometimes the one and sometimes the other mineral 

 being the intruder, suggesting a contemporaneous origin. The 

 true explanation, however, is probably that a recrystallization of 

 both minerals took place, after the formation of secondary epidote, 

 under the influence of contact-metamorphism. 



The diorite and hornblende-schists between Gilgit and Chalt have 

 been riddled in all directions by numerous dykes and veins of 

 granite, which form a complete network, the intruders being 

 the normal and acid varieties of the Hatu Pir Granite. The 

 metamorphism produced by this profuse invasion of granite has 

 been intense. Whether or not the hornblendic rocks and schists 

 had suffered any metamorphism prior to the intrusion of the granite 

 I cannot say. The contact-action of the granite, and its accom- 

 panying diorite, is sufficient to account for the fairly uniform 

 metamorphism of the hornblendic rocks and schists ; and in the 

 absence of any evidence to prove prior metamorphism such previous 

 metamorphism cannot be assumed. Capt. Roberts writes: — 'The 



a J. G. S. No. 222. 2 b 



