174 KRAFFT: EXOTIC BLOCKS OF MALLA JOHAR. 



schist plunges into the hill, its whole dimensions cannot be seen, but 

 there are visible at least 15,000 cubic yards, and which must weigh 

 more than 30,000 tons." 



Sir Archibald Geikie thinks there can be no doubt that these 

 enormous fragments were torn off from the underlying crystalline schists 

 and were floated upwards in an ascending flow of molten basalt. 



Site of volcanoes uncertain. — But now the question arises : Where 

 are these volcanoes situated ? As they were in action during eocene 

 times we cannot of course expect to find well preserved cones any- 

 where, but remnants of these must be present, and it should be 

 possible at least approximately to fix the site of these old volcanoes. 



At present, however, no direct attempt can be made in this 

 direction, as our knowledge of the structure of the Tibetan districts 

 to the north, north-east and east of Johar is extremely limited. We 

 know from Strachey's researches that great masses of "greenstone" 

 are found in Hundes, viz-, to the west of the Manassarawar lake and 

 to the east of Kiunglung on the Sutlej. These rocks are according to 

 Strachey older than the subrecent deposits of Hundes l and no doubt 

 contemporaneous with the Indus valley volcanoes and with those of 

 Johar and the Chirchun area. It appears that they represent lava 

 flows, but no details are known. 



On the other hand I could see from the boundary range that the 

 Johar volcanics extend several miles to the north, north-east and east 

 into Hundes, especially in the Kiogarh high plateau, the eastern 

 limits of which are yet unknown. 



The country intervening is, according to Strachey, covered with 

 mesozoic and subrecent deposits. 



In view of the huge size of some of the blocks ejected, the 

 position of the Kiogarh high plateau in the centre of the Johar volcan- 

 ics and the great thickness of the latter, it might be supposed that 

 the sources of discharge lie within this plateau. But there are other 

 considerations to be borne in mind. The absence of dykes in the 

 flysch in Johar points to the volcanic vents being at a greater distance, 



1 Loc. cit., p. 310. 

 ( 43 ) 



