THE KOTAH D(JN. 33 



deposits :— (1) There is no unconformability visible between them 

 and the undoubted Siwalik conglomerate forming the low range 

 between the dun and the plains. (2) Slight sharp local flexures can 

 be seen in them here and there. (3) Every gradation of dip, from 

 the horizontal beds of the dun to the distinctly inclined strata of the 

 range south-west of the dun, can be made out. (4) They cannot 

 manifestly be imputed to any Recent river-bed. (5) Even where 

 horizontal, they are of great thickness. (6) Wherever undoubted 

 modern gravels can be seen covering certain portions of the dun 

 their thickness is trivial, and the bed-rock can be nearly always made 

 out underneath. 



The detailed sections which follow will illustrate the strati- 

 graphy of the Kotah dun, and establish the six propositions just 

 enumerated. 



This river presents many shingly terraces, some overgrown 



with vegetation, which are manifestly of recent 

 BaurN.(BhaolN).(i) . . & ' f J , 



origin ; whilst, on the other hand, still higher 



banks, sometimes in two or more steps, and rising 200 ft. above the 

 present river-bed, mark the ancient levels of the river as it cut its 

 way through the horizontal Upper Siwalik beds. From one end of 

 the river to the other the Siwaliks are horizontal, save for a dip of 

 not more than 3 S.W. near the ironworks. The river runs very 

 nearly along the boundary between the dun and the higher Nahan 

 hills. Sometimes it actually follows the boundary, and shows sec- 

 tions of the Nahan sandstone and purple shales with the conglomerate 

 horizontally disposed against them, as against a cliff. In other parts, 

 especially towards the south, the boundary is a little on the eastern 

 side of the river. The conglomerate is generally, throughout this 

 river section, hardened by calcareous infiltrations. 



From a point near 1,510 ft. bar. 1 there are exposures of horizontal 



beds of the Siwalik conglomerate with the sandy 

 Dhuni gadh (Dhooni . & f 



gacih, a few miles W. of clay basis, sometimes hardened. They conti- 

 nue horizontal down to a point due west of 1,556 



1 Bar, — Point on the Forest Maps fixed barometrically. 



C ( 91 ) 



