42 



GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



in one direction and forming a great sequence. It is therefore only 

 in the synclinals that I met with the haimantas above mentioned, 

 whilst the older granitic gneiss generally appears only in the anticli- 

 nals or near the base of rock sequences along lines of dislocations. 



Several such synclinals (often reversed) are found within the belt 

 of the Lower Himalayas, which enclose long strips of sedimentary rocks 

 enclosed by metamorphic schists. I am myself convinced of the prob- 

 ability, which is based not only on lithological similarities, but also 

 on stratigraphical evidence, that these inclosures of sedimentary 

 rocks are, in greater part, if not entirely, members of the haimanta 

 system, which is well exposed north of the Southern range of the 

 Central Himalayas. I shall have to refer to this question later on. 



The Southern range of the Central Himalayas coincides more or 

 less with the most important of the great anticlinal flexures which 

 occur within the crystalline belt. It is generally an immense reversed 

 flexure, and as the top of the arch has been denuded away, we see 

 now nothing but a succession of beds steadily dipping to north or 

 north-east at an almost uniform angle of from 30 to 40 degrees. Were 

 it not that one traverses from south to north respectively, metamor- 

 phic schists (vaikritas), and gneiss, granitic gneiss, and again vaikritas, 

 it would be difficult to decide whether one has to do with an inverted 

 flexure or a normal sequence, in which the schists to the south form the 

 oldest beds. The vaikritas which rest conformably on the granitic gneiss 

 of the Southern range along its northern slope, pass as will be seen 

 gradually into the haimanta system. The boundary between the two 

 systems could therefore only approximately be laid down on the maps. 



In addition to the two great rock groups of the metamorphic belt, 

 i.e.y the granitic gneiss and the schistose strata of the vaikritas, there 

 are intrusive rocks, which play an important part in the geology of the 

 Himalayas. Foremost amongst these rocks must be considered the 



great masses of granite which penetrate the older 



Granite. . . . 



granitic gneiss and schists and are even seen to 

 traverse the overlying haimanta system. The granite forms usually a 

 perfect net-work of veins in the vaikritas, and in the older masses of 

 the granitic gneiss, but in places these veins swell out to immense pro- 



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