230 MIDDLBMISS: GEOLOGY OF HAZARA AND BLACK MOUNTAIN. 



Fig. 43- 

 b = Limestone. 

 a — Quartz-schist. 



The Sirun R. from near Seree- 

 Sher-Shah exposes a continuous 

 section in the Infra-Trias of this 

 area. The river-bed is a very 

 deeply eroded channel or gorge 

 traversing across the strike from 

 north to south. It is broken up 

 into a number of pools of deep 

 water between which a variable 

 current runs dependent on the rain- 

 fall in the hills to the north, or on the moulting snow of Bahingra in 

 the spring. As is usual in many parts of Hazara this river-bed is 

 one of the main footpaths from village to village. The section 

 exposed along it is one continuous series of fold after fold among the 

 limestones, sometimes much mixed up with Tanol quartzites. It is 

 from evidence here and on the neighbouring hills that I am inclined 

 to think that many of the beds of the schistose quartzites among the 

 limestones are due to a change of facies in the deposit, and that 

 they here are contemporaneous with what is limestone in other 

 parts. 



The lower reaches of the Sirun R. between Beer and Soha also 

 shew violent folds in the Infra-Trias limestone. Still further down- 

 stream in the little hill north-east of Kuchchee the Infra-Trias is 

 much more sandy than elsewhere. Its lower beds in particular are 

 darker in colour, and the rock appears in the curious form of a 

 pseudo-conglomerate. At first sight some of this material seems 

 suggestive of rolled fragments of Infra-Trias limestone scattered 

 through a sandy matrix, but ultimately abundance of passage forms 

 were found connecting it with the ordinary Infra-Trias limestone 

 which is generally much scored across and across by the peculiar 

 form of weathering explained in chapter II, page 24. The cause of 

 this appearance seems to be that the limestone, by the presence 

 of more sandy material along with calcareous, became first concre- 

 tionary, then a brecciation of the^rock took place with a re-cement- 

 ( 236 ) 



