Vol. 56.] THE GEOLOGY OF GILGIT. 363 



limestones are dark bluish-grey — the Gilgit limestones are for the 

 most part white. Nevertheless, this difference does not appear to me 

 to be material. The Krol limestones are not invaded by granite, 

 whereas the Gilgit limestones are profusely intruded by this igneous 

 rock and the contact-metamorphism has been most intense. One 

 of the limestones of the Ashkurman Valley (a compact unaltered 

 rock not invaded by granite) is bluish-grey — this coloration being 

 due to the presence of 0-102 per cent, of amorphous carbon (p. 360). 

 In the other Gilgit limestones the contact- action of the granite 

 by which they were invaded caused a segregation of the iron and 

 carbon contained in them into magnetite and graphite, and thus 

 restored the carbonate of lime to its natural whiteness. Even in 

 the Simla region I came across white limestone on the flank of 

 the granite-mass of the Chor Mountain. 



In the Gilgit area the first outcrop of the limestones is between 

 Gilgit and Nomal, and the last is at Gircha, the distance across the 

 strike being about 47 miles. I need hardly say that I do not regard 

 the successive outcrops, presented to us in this section, as members 

 of an ascending conformable series. Many considerations lead me 

 to believe that we are dealing herewith a compressed series of 

 folds. The same beds have, I believe, been repeated again and 

 again, and a delusive appearance of great thickness and regular 

 succession created by monoclinal folding. 



The saccharoidal limestones of Gilgit-Nomal and of Nilt-Hini 1 

 consider to be beds on the same, or about the same, horizon. 

 Differences in the thickness or number of the beds are probably 

 due to local variations in the conditions of deposition. The Altit 

 * stinkstones ' probably belong to a slightly higher horizon. They 

 occur only in this section, and either thinned out westward, or 

 were pinched or faulted out in the intense compression and folding 

 that took place. The Gujhal dolomites and limestones differ 

 greatly in appearance, condition, and composition from the lime- 

 stones referred to above. They belong apparently to a higher 

 horizon, and are probably of Triassic age. Their great thickness 

 in the Gilgit-Kilik section is perhaps due to repeated folding and 

 compression. 



That the limestones in the Gilgit area have been crumpled up 

 and repeated in a series of compressed monoclinal folds is, I think, 

 proved by the evidence afforded by the ' stinkstones/ Capt. Eoberts 

 assures me — and I made a special inquiry from him, in order that 

 no doubt might remain as to the fact — that the ' stinkstones ' are 

 composed of a series of about twenty bands, each of which is made up 

 of a solid central bed of limestone with innumerable thin bands of 

 limestone from 1 to 12 inches thick on either side of it (p. 352). 

 It is not at all likely that so peculiar an arrangement of one thick 

 bed lying in the middle of numerous thin beds would be repeated in 

 the course of ordinary deposition twenty times in succession. It is 

 much more easy to believe that a single composite band, composed 

 of one thick bed in the middle of a number of thin beds, was 

 crumpled up and compressed into monoclinal folds in which the 

 band was repeated by folding twenty times. 



