4 8 



GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



formation, and they may be even tertiary ; it is therefore not 

 quite improbable that the great granite intrusions of the Central 

 Himalayas belong to a period of great secular changes, which possibly 

 endured during all the lower and middle tertiary times, characterized, 

 first, by the appearance of granites in the dislocations which formed 

 and later on by basic rocks, such as the diallages, serpentines and 

 traps. 



Against this theory, which as regards the granite is purely con- 

 jectural, and based on comparison with neighbouring areas, might 

 be urged the negative evidence, i.e., the absence of granite in any 

 of the sedimentary formations above the older palaeozoics (haimantas). 



It must, however, be remembered that throughout the belt of sedi- 

 mentary formations between the Southern range of the Central Hima- 

 layas and the line ef the Hundes watershed, no intrusive rocks are 

 met with ; and this circumstance is probably explained by the as- 

 sumption that these intrusive rocks have appeared chiefly along lines 

 of great dislocations only, one of which seems to run along the 

 northern slope of the Southern range of the Central Himalayas, whilst 

 the other probably runs parallel and near the northern margin of the 

 Hundes plain. The belt of sedimentary strata which is bounded by 

 these two dislocations represents, of course, a once much wider area, 

 now compressed into a most complicated system of flexures, forming 

 one solid block of strata, in which only local, though occasionally very 

 extensive faults are met with. The great southern system of disloca- 

 tions in which the granites appear affects chiefly the older metamor- 

 phic and the schistose (vaikrita) areas. Hence, as far as I could 

 ascertain, nothing but these strata or the adjoining haimantas are 

 affected by the granite intrusions. The Hundes dislocation has 

 brought the tertiaries in direct contact with the metamorphics of the 

 " Kaila*s " range, the watershed between the Sutlej and Indus. This 

 dislocation the "traps" and other basic rocks have filled, and have 

 there produced the partial lithological changes in the older tertiaries 

 which Stoliczka also noticed in the Indus area. 1 



1 Mem. V, pt. Ill, 337—354- 

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