Chap. IV.] 



NAHUN AND SIVALIK GROUPS. 



141 



W 



Mm 



Q ^ 



M (I 



« g 



g 1 



« « 



B o 



« d 



M 



O 

 S 



w 



s 



The Una section. 



narrow ridge of Naina Devi as far up as Fung- 

 wanu, but from Belaspur to Koseree I found no 

 remnant of the Bubhor conglomerate. 



However regular the ridges of this region 

 may be in direction, their details of structure 

 are exceedingly complicated. . The section from 

 Una to Budsur (Fig. 17) affords complete 

 exemplification of these intricacies, which are 

 of the same kind else- 

 where. The two ridges 

 of Naina Devi and Sola-Singhee seem to have 

 grown out of the broader and less defined ridge 

 over Kundulu. They are both formed along 

 synclinal axes, the dip being inwards on each 

 flank, and the rocks of both are certainly the 

 lowest of the section, the softer, newer rocks 

 appearing in the valleys and plains. In the 

 former position, as in the Sutlej valley about 

 Koseree, the phenomenon reminds one strongly 

 of the case of the nummulitic outliers between 

 the Krol and the Boj, yet the parallel does 

 not seem complete enough to admit of our 

 adopting the same mode of explanation, namely, 

 the pre-existence of the lidges of older rocks, 

 or at least not to nearly the same extent ; 

 the evidence here is strongly in favour of fault- 

 ing, and of folded flexures. In the sections of 

 the south flank of the first ridge, under Naina 

 Devi and in the Sutlej, we have seen a sharp an- 

 ticlinal bend, with apparently some faulting ; in 

 the Una section to the west, this anticlinal axis 



