Chap. IV.] nahitn and sivalik groups. 107 



the two groups are by no means well exemplified in this section, the 

 Nahun rocks being far less disturbed than usual, but the immediate 

 contact is typical, at least for this region between the duns. In the 

 valley north of the town thick brownish gray sandstone and nodular 

 clays are nearly horizontal near the contact with black slates and the 

 nummulitic rocks. On Nahun hill these sandstones and clays have a 

 moderate dip to north. The Markunda flows for some distance through 

 the Nahun rocks, obliquely to the strike before reaching the outer junc- 

 tion, along 1 which it takes a bend for a few hundred feet. The view 

 here is a very striking one to the geologist, especially if he be to any 

 extent acquainted with the two groups here seen in contact ; it is 

 represented in Plate I. looking westerly, down the river, to the bend, 

 where it again turns southerly ; there is a vertical north and south 

 cliff of the outer rocks, running into a steep, east and west cliff of the 

 Nahun beds at about half the height. Everything conspires to increase 

 the contrast ; the Sivalik beds are thick, soft conglomerates, sands, and 

 clays of a dull earthy brown colour, and have a remarkably steady dip 

 of 25° to north, thus going apparently under bright brown, purplish 

 red clays, and gray soft sandstones of the higher part of the hill. Indeed 

 the superposition is more than apparent ; however abnormal, it is to a 

 small extent actual ; a vertical plane, starting from the younger rock 

 upward, would certainly cut off on the south some of the older ones above. 

 The dip in these is higher in the same direction, and considerably 

 crushed, suggesting, if nothing else did, that all are not in order ; the 

 appearance, however, is so deceptive that previous observers, who cannot 

 have failed to notice so conspicuous a section, have interpreted it as a 

 case of normal sequence. All the large boulders in the conglomerates 

 are of a rock undistinguishable from that of Nahun. 



In this junction we have a very fresh instance of a structure that has 

 often attracted notice, and is still a puzzle in the sections of Alpine 

 regions ; a more complete case could not be found. In highly contorted 



