202 VREDENBURG : SKETCH OF BALGCHISTAN DESERT. 



is no indication of any unconformity anywhere throughout the whole 

 sequence of marine strata. Even where we find indications of shallow 

 water conditions as amongst some of the Cardita beaumonti beds 

 and also in the uppermost Khirthar strata of Saindak, there is no 

 sign anywhere that folding, of the beds had commenced. All these 

 deposits seem to have been laid down horizontally without any 

 interruption in a gently subsiding area. Now, the generally vertical 

 trend of the intrusions, so well marked principally in the case of 

 narrow dykes, the absence of any distinct signs of dynamic metamor- 

 phism in regions where the stratified rocks are altered to the utmost 

 degree, all tend to show that not only had the folding of the rocks 

 commenced, but that they had reached very nearly the same 

 position where we see them to-day at the time when the plutonic 

 masses were injected. 1 



As my hurried observations may be regarded as not sufficient to 

 establish the conclusions advanced, the alternative explanation might 

 still be offered, that some of the large masses are of the nature of 

 laccolites. This might allow them to be attached to the series of 

 older volcanic phenomena ; still it would remain a necessity to 

 regard them as much later than the bulk of the tuffs and more 

 basic eruptions. 



In any case the relative ages of at least three groups of igneous 

 rocks, none of which are newer than pliocene, can be very clearly 

 made out as follows : 



Firsts volcanic rocks, properly referable to the flysch ; mostly 

 tuffs, and locally intrusive masses, many of which are basic. Their 

 range in time is from upper cretaceous to middle eocene, and they 

 are anterior to the folding of the district. 



1 The case will be mentioned hereafter (page 48) of a volcanic rock which appears to be 

 of Siwalik age, though this ia not absolutely certain. This observation might lead one to 

 infer that the granitic and dioritic intrusions represent the deep-seated portion of eruptions of 

 that period. The instance mentioned, even if correct, is too local and isolated to warrant 

 such a conclusion, The granitic intrusions are of such colossal dimensions that, had any 

 eruptions of comparable magnitude taken place at so late a period as the Siwalik age, there 

 could not but exist abundant indications of them ; nor is it likely that the cones themselves 

 could have been so completely denuded as to have left no trace. 



( *4 ) 



