CHOKAMB AND KOTR1 DfJNS. Si 



The Sona N. and Manda"lti R. are longitudinal streams which 

 follow the strike of the softer beds, whilst the corresponding ridges 

 on either side of them are made up of the harder Nahan sandstone. 

 The Kotri or Sanneh river (37) is a transverse stream flowing through 

 the Chokamb and Kotri duns. 



The Sona N. (or " gold river " as the word signifies) joins the 



Ramganga a little below Boksar, and is sepa- 

 Sona N. . r 



rated from the plains by a well-marked ridge of 



Nahans, the direct continuation of the same band which is seen in 

 the lowest reach of the Ramganga, and which has been already de- 

 scribed. From henceforth this Nahan zone holds its own fronting the 

 plains all the way up to Laldh^ng. There is nothing remarkable 

 about it in this locality : its general lie being very much the same as 

 in the Ramganga. The road from Kalu-Sh£hid (Kiloosyud) to 

 Mota-Sal (38) exhibits a good section through the upper portion of it, 

 which is dipping at angles of 40 and 35 N.N.E. or N.E. Its passage 

 up into the sand-rock series also presents no new features ; the line of 

 junction as drawn on the map being seen to be nothing but a prolong- 

 ation of the line which cuts the Ramganga. The sand-rock stage, in 

 like manner, has no complications until the Sona N. is reached ; but 

 dips steadily N.N.E. and N.E. at angles of 30 and 45 . There is 

 then a certain amount of complication, by the introduction of the 

 Siwalik conglomerate in a very thin broken bed ; and by the flexur- 

 ing which lets in the Nahans once more on the north side of the Sona 

 N. This line of disturbance is a continuation of the line of thrusting 

 or reversed faulting observed at the junction of the Pelani and Rdm- 

 ganga rivers. 



As stated above, the general course of the Sona N. is through the 

 sand-rock stage. For some distance up stream from the Rdmganga 

 the dip is 15 N.N.E. No other formation is seen in the actual river- 

 bed until near Hathi-Khund ; but on the slopes north of the river-bed 

 the Siwalik conglomerate band, which has thinned near Boksar, is 

 continued for a short distance and then becomes lost, to reappear 

 again at Hithi-Khund. Thus, the horizontal section No. VII shews 

 F ( 139 ) 



