GEOLOGICAL DIVISIONS. 203 



Second, great intrusions of granites, syenites, and diorites that 

 were injected amongst the rocks during orogenic movements. They 

 cannot be older than upper eocene. 



Third, dykes and sills of basalt and dolerite posterior to the period 

 of maximum disturbance) but in all probability older than the Siwaliks. 



Hasty as my observations were, I do not believe that there is room 

 for any doubt respecting the newer age of the acid and intermediate 

 plutonic intrusions relatively to the truly volcanic rocks of the " flysch," 

 Moreover, their association may be fortuitous, even though a similar 

 association may be found in other regions — in some parts of Europe, 

 for instance— for this may signify merely that in the latter case the 

 geological history has followed identical phases. Yet in our ignorance 

 regarding the genesis of both volcanic and plutonic rocks at great 

 depths beneath the earth's surface, it is not possible to affirm that 

 there is no connection between them. 



If, on the one hand, it seems advisable to separate these plutonic 



Possible relation to the rocks from the volcanic products of the flysch, 

 Himalayan granites. on t h e ther hand one is tempted to associate 



them with the igneous intrusions of the Himalayas. It is quite possi- 

 ble that in the Himalayas, besides an archaean gneiss, there might be 

 later intrusions ; and if they belong to the same system as the Balu- 

 chistan ones, it would confirm the view expressed by General 

 McMahon and other leading petrologists as to the tertiary age of the 

 Himalayan granites. 



The existence of these three successive, if not independent, series 

 constitutes a source of great uncertainty in a hurried examination of 

 the district ; for, unless their stratigraphical relations can be made 

 out with accuracy, it is often impossible to decide which of these 

 series many of the observed rocks should be referred to, and hence 

 their relative ages often remain doubtful. 



Section 4. — Siwaliks. 



It has been mentioned that, besides the marine strata, there are 

 land deposits of Siwalik age. These outcrop in a manner somewhat 



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