40 MIDDLEM1SS: PHYSICAL GEOLOGY OF SUB-HIMALAYA. 



In this stream, on the contrary, the dips are on the other side of 

 Tehra sot (Taila s6t) the anticlinal, namely, in a direction E.N.E., 

 ( I3 ^* and this direction continues completely across 



the north-west end of the Kotah dun. At the point where the Garja- 

 ka-s6t (14) is crossed the conglomerates dip at 30 N. E., and they keep 

 this dip up to the 1,893 ^ eet hill to the north. Their junction with 

 the Nahan sandstones is not seen in a definite exposure ; but there 

 seems no doubt that it is a reversed fault. The material of the con- 

 glomerate here is somewhat more angular as the higher hills are 

 approached, a fact indicating the limit of deposition of the Upper 

 Siwalik stage in this locality. 



The structure of the Kotah dun and the fringing hills, therefore, 



is remarkable for the very perfect way in which 

 Kotah dun as a whole. ... . 



the features of positive and negative contortion 

 impressed on the Siwalik strata have been directly influential in 

 determining their present surface features. The flat dun is composed 

 of level conglomerates and clays, whilst the low hills to the south, in 

 height and importance, are determined by anticlinals the steepness 

 of which corresponds to the steepness of the hills. Wherever these 

 low hills slope gradually down to the flat country, the dip of their 

 strata falls gradually in unison with it. On the other hand, at Sita- 

 bani this is not the case, the strata do not dip gradually under the 

 dun, but are turned up sharply in the opposite direction, owing to 

 elevation along the south side of the fault. That is to say, the sudden 

 way in which the hills rise to the south is nothing more than the 

 obvious result of upheaval in that direction with production of a fault- 

 scarp. Again, at Chuna Khan and Madan Bhel, the southerly dip of 

 the strata has increased rapidly to the vertical at the edge of the 

 plains ; and this corresponds to the very prominent steep low scarp ? 

 which one cannot fail to notice as we travel along the sub-montane 

 road from Kciladhungi to Bael parao. The extinction of the Kotah 

 dun to the north-west is a signal that the gentle undulations of the 

 Upper Siwalik strata are giving way to the more compressed state of 

 things which we shall find obtains in the country now to be described 

 between the Kotah and Pa"tli duns. 

 ( 98 ) ■ 



