274 MIDDLEMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



of least resistance. On the other hand, if the rock is really a granite 

 all through, that is to say, the product of a molten magma drawn 

 from some unknown underground reservoir, then its activities as a 

 granite, its function as an intrusive igneous rock, have been kept well 

 under control. 



Probably the first idea of many people after superficially studying 

 Its mode of intrusion the Himalaya would be to regard the great 

 among the strata. crystalline axis as having been the cause of the 



upheaval of the mountain mass, the prime mover, which bursting 

 through the other rocks wedged them apart and folded and contorted 

 them. 1 



But studied in detail this theory does not hold good for a moment. 

 There are no violent disruptive phenomena connected with the 

 gneissose-granite, as manifested in its position among the metamor- 

 phic crystalline schists. On the contrary, it appears rather to have 

 quietly and under enormous pressure accommodated itself between 

 the schistose strata, in part consuming them probably as it went 

 along, but leaving here and there undigested fragments as inclusions 

 near the margin. Everywhere in the mountains its parallelism as 

 regards foliation and the margins of its beds has been remarked on. 

 I n many places it occurs in great beds which may be followed in 

 their course through a mountain massif, just as we might follow a 

 thick stratum of some sedimentary rock or a flow of an igneous rock. 

 I cannot think that any one, after studying it in detail, would come 

 to any other conclusion than that, if conceded a granitic origin, it was 

 formed as great laccolites, deep down below the surface of the 

 earth, under such enormous pressure of the superincumbent rocks 

 that an eruptive function was generally denied it, and it had perforce 

 to follow the resulting lines of least resistance, that is to say, along 

 the divisional planes of the rocks among which it was squeezed. 



1 From a copy of the Presidential address to the Geologists' Association for 1895 by 

 General McMahon, kindly sent me by the author, it would seem that this belief is enter- 

 tained by at least one who has claims to be considered much more than a superficial 

 student of the Himalaya. Yet, among the many well reasoned-out conclusions in that 

 paper, I venture to still reiterate that on this one point I think General McMahon is 

 completely wrong. 

 ( 274 ) 



