170 KRAFFT: EXOTIC BLOCKS OF MALLA JOHAR. 



those disturbances, and any causal connection between the latter and 

 the blocks is therefore impossible. 



Nor is it at all conceivable that folding or faulting should have 

 brought about those features, which were described in the above 

 chapters. None of the theories alluded to would explain the presence 

 of the volcanics and their intimate connection with the exotic blocks. 



A simple and as I believe satisfactory solution of the problem is, 

 however, obtained if we attribute the exotic blocks to volcanic out- 

 bursts. 



We have seen above that the exotic blocks are involved in volcanic 

 rocks and it cannot for a moment be doubtful that both the volcanic 

 and non-volcanic rocks came into existence simultaneously. No more 

 likely conclusion can therefore be drawn, than that the exotic blocks 

 are caused by volcanic eruptions. They must be derived from rocks 

 which were shattered into pieces by steam blasts and hurled up and 

 ejected or floated upwards by erupting lavas through volcanic vents. 



The exotic blocks thus must be understood to be fragments, torn 

 from rocks in situ, through which the eruptive forces opened their 

 way. In many cases the limestones had been intruded by igneous 

 rocks, previous to their being torn off and ejected, and some of them 

 underwent great pressure subsequently with the result that the veins 

 were plicated. 



Let us for a moment put aside those huge masses of grey lime- 

 stone and Gieumal sandstone, found within the Kiogarh high plateau 

 and the Balchdhura heights respectively and only consider the accu- 

 mulation of lavas and smaller non-volcanic blocks, which is general in 

 Johar. Numerous instances of similar occurrences from other parts 

 of the world can be quoted, which are universally explained by 

 volcanic outbursts. The fragments of slate, which largely make up 

 the volcanic cones of the Eifel, the fragments of cretaceous limestones 

 found on the slopes of Mount Vesuvius, the abundant non-volcanic 

 materials imbedded in the carboniferous volcanic rocks of the Firth of 

 Forth, 1 sandstones with rhaetic fossils, limestones with liassic fossils 



1 Geikie, Transactions Roy. Soc-, Edinburgh, Vol. XXIX, 18S0. 

 ( 44 ) 



