SOS YREDENBURG: SKETCH OF BALtJCHISTAN DESERT. 



the whole period of orogenic movements (see ante, page j)~ 

 Nevertheless, considering, on the one hand, the short time, geolo- 

 gically speaking, that was necessary to produce the bulk of the 

 upheaval, and, on the other hand, the indistinctness of any evidence of 

 recent movements, it seems reasonable to admit that if the orogenic 

 forces have not entirely ceased, at least they have dwindled down 

 to a very low ebb. 1 



It is true that the whole of this region is frequently visited by 

 earthquakes, which shows that the earth's crust is still there in a> 

 state of unstable equilibrium. But it is not proved that these seisms 

 are connected with folding of the strata. 



An observation, unfortunately somewhat doubtful, which was* 

 Volcanic rocks perhaps made at Robat, would, if confirmed, indicate 



of Swahk age. foe existence of one link at least, between the 



recent epoch and the period at which the Siwalik strata were 

 deposited. Throughout the enormous areas occupied by outcrops 

 of the Sivvaliks in India I do not know of any instance of these strata 

 having been found affected by igneous intrusions, or containing any 

 volcanic material other than that derived from older rocks. On the 

 right bank of the Robat river, near Fain Robat, are some highly 

 tilted strata consisting of conglomerates and shales which I first took 

 to be Siwaliks, but which are so much concealed by recent gravels 

 that it is difficult to make sure of their characters. On finding one 

 of these strata to be a volcanic rock, I concluded that these sediments 

 cannot be the Siwaliks, but the older rocks of the flysch period, 

 which are represented by well developed tuffs and agglomerates in 

 some of the neighbouring sections, and whose typical appearance 

 seemed masked owing to the imperfection of the exposure. Micros- 

 copic examination shows that the rock exhibits a degree of freshness 

 which is not observed in any of the volcanic products that can be 

 assigned with certainty to the flysch period. The first impression 

 given by the associated strata as being Siwalik may therefore have 



i Mr. Griesbach has shown that anticlinal and synclinal flexures are still in process 

 of formation in certain parts of Turkistan. Rec. Geol. Surv. Ind., Vol. XIX, pp. 260- 

 261. 



( 30 ) 



