84 SUB-HIMALAYAN ROCKS OF N. W. INDIA. [CHAP. III. 



dipping at a high angle towards the sandstone ridge ; the junction occurs 

 at a short distance below the crest of the ridge on the north-east. All 

 along the south-west face of the ridge, from Subathu to its termination 

 east of the tunnel, the strong sandstones and red clays have a high dip 

 inwards ; along the centre there is a synclinal bend producing a fractured 

 upturn of the beds towards the plane of junction. Thus on both sides 

 every feature of 'the case is suggestive of a great fault with an upthrow 

 to the north-east, yet if there be any force in the argument based on the 

 sections of Subathu, such is not the case to any extent. The relative 

 position of the beds in contact on the Boj are about what I suppose 

 them to have been originally : on both sides of the junction the beds 

 are about 1,500 to 1,800 feet higher in their respective series than their 

 representatives at Subathu : and I may notice, though it does not 

 materially affect the question, that this is about the difference of level of 

 the two localities. Again, to the east, in the connecting ridge at the 

 head of the Jalar valley, there is a section of the junction precisely like 

 that I have just described, while in the low ground on both sides the 

 soft bottom beds form the contact, which is always very obscure in such 

 positions. Similarly to the north-west of Subathu the junction occurs 

 in low ground, and in the softer beds, so that it is greatly concealed. 

 There is another step in the same line of argument. All the num- 



mulitic beds about Subathu may be described as 

 Contrast of rocks along 

 inner and outer bounda- marginal and mixed when compared with their 

 ries. 



equivalents a few miles more to the south-west 



along the outer boundary, at least this seems to me a plausible inference 

 from facts. The section seen in the Sursulla, two miles east of Kalka, 

 gives a good instance of this contrast. On the north of the boundary of 

 the Subathu group with the succeeding band of the Sub-Himalayan 

 series, the dark brown nummulitic clay is the only rock exposed for 

 more than quarter of a mile. The section is not unbroken, but the 

 clay shows at intervals, in some places of several hundred feet in 



