4 GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



In an area which has suffered such a degree of contortion and 

 lateral crushing, one must naturally expect to find much faulting. 

 Indeed such is the case, and in many instances and over great dis- 

 tances, the inversion of the folds has resulted in oblique faults of 

 great magnitude, producing often that scale-structure so common 

 in most areas of folding. 



The valley of the Sutlej in Hundes will, I believe, be found to be 

 a line of great dislocation; the mountain range (Kaila^s) which 

 divides the Sutlej from the Indus valley, is by all accounts a repeti- 

 tion of the Central Himalayas, i.e., it consists of an anticlinal of 

 metamorphics followed by a synclinal of sedimentary strata. None 

 of the fossiliferous series of the northern range of the Central 

 Himalayas seems to be found along the southern slope of the Kail£s 

 range, and it is therefore probable that this mountain range is simply 

 a repetition, by faulting, of the Central Himalayan system. 



Description of the Geological formations. 



/. Crystalline rocks. 

 My work in the Himalayas, which occupied several years, was 

 chiefly devoted to the study of the sedimentary rocks, which form 

 a more or less continuous belt north and north-east of the Southern 

 or highest range of the Central Himalayas. It was partly owing 

 to want of time, and partly necessitated by the difficult nature of 

 the country, that I had to limit my detailed observations to the 

 fossil-bearing formations ; as regards the belt of crystalline forma- 

 tions, I could, in most cases, do little more than just trace out the 

 boundary between them and the overlying sedimentary series. The 

 main mass of the Himalayas, Central and Lower ranges of it, is formed 

 of crystalline rocks of enormous thickness. So far seems certain, that 

 within the crystalline rocks two distinct systems exist ; namely, an 

 older one of granitic gneiss, formerly called the central gneiss, and 

 a schistose series which apparently overlies the former. Of the 

 granitic gneiss I will only say this, that later studies 1 within the 



1 McMahon, C. A.— Rec. Geol. Sur. Ind., X, 204-223; ib., XVII, 53-73 ; ft., XVII, 

 168-175; XX, 203-205; Geol. Mag. 3rd Dec, IV., 212-220. 



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