114 SUB-HIMALAYAN ROCKS OF N. W. INDIA. [CHAP. IV. 



one spot, in the Koon, there is a complete interruption to the Nahun 



band, the upper Sivalik clays being in contact with the Subathu group. 



Kegarding the lithological characters of the Nahun group here, there 



♦ .,,..,, L is little to be said. Throughout the entire distance 

 Lithological character ° 



of the Nahun band. f rom N e p a i to the Pinjore dun the fine sharp, 



gray, soft sandstone, which, in its essential characters, is so characteristic 

 of the whole Sub-Himalayan series, almost exclusively prevails. It 

 occurs in massive beds often fifty and a hundred feet thick, and showing 

 little or no trace of lamination. It is in this rock that lumps of 

 lignite are very frequently found. The clays, occasionally interstratified 

 with this sandstone, are generally gritty, nodular, and ferruginous, and are 

 most abundant in the lower part of the group, on which account they are 

 best exposed along the outer boundary. The iron-ore worked at Dechouri 

 and Kaladoongi, at the foot of the Nairn Tal hills, is one of these ferrifer- 

 ous clays ; and beds of analogous character can be traced far to the 

 westwards, as, for instance, in a gully opposite Kolur, on the north bank 

 of the Batta. 



The most remarkable exception, within this district, to the general 



' „ . uniformity in composition, is to be seen in the 



The Soma conglome- J x 



rate - section of the Soma glen, under Masuri. There is 



a massive band, 400 feet thick, of coarse boulder conglomerate ; in 

 composition it most closely resembles the very uppermost beds of the 

 Sivalik conglomerate, such as are seen in Nagsidh and Motichur hills, or 

 the still more recent deposits, in the gorge of the Ganges. The boulders 

 are thoroughly water-worn, and almost exclusively made of the hardest 

 subschistose quartzite, such as are only found in streams coming from the 

 heart of the mountains. This feature is, no doubt, significant, as it 

 contrasts most markedly with the composition of the conglomerates in 

 an apparently analogous position in the sections about the Sutlej in 

 which the debris is chiefly local. This mass is equally strange in its 

 mode of occurrence ; it appears, with little or no transition of characters 



