MEDLICOTT — ALPS AND HIMALAYAS. 47 



the case of those great features, moreover, one can imagine very con- 

 siderable \dolence of distm-bance to occur without causing any alte- 

 ration. Neither of these pleas suggests itself in the case of such 

 streams as the Guggur and the Batta, the springs of which are not 

 further in than the first ridge of the mountains. 



The most apparent instance of the feature under notice is found 

 in the course of the Sutlej. This mighty torrent debouches upon 

 the plains at a point where the zone of the Subhimalayan rocks has 

 become greatly widened, owing to the retreat northwards of the 

 mountain-range ; thus, before it reaches the outermost zone of the 

 Sivaliks, the Sutlej has run for many miles through comparatively 

 low hills of soft roclis of Lower Sivalik or Nahun type. At Bibhor 

 the river cuts the last of these inner ridges ; and on the outer flanks, 

 on both sides of the stream, there are massive beds of coarse con- 

 glomerate, of boulders such as only occur in the main river-channels. 

 These beds are now raised to the vertical; and in both directions 

 along the strike these conglomerates pass graduall}'", within a few 

 miles, into the ordinary sandstones. The presumption from such a 

 coincidence seems irresistible, that the Sutlej itself had deposited 

 these banks of boulders on the spot where it still flows. Whatever 

 view one may take of the precise form of the contortions which now 

 exist in these strata, their magnitude is unquestionable ; yet, from 

 the circumstances just noticed, the conclusion would seem unavoidable 

 that they were produced at the very surface, and so gradually that 

 one can imagine the process inappreciable to contemporaneous 

 observers, had any such existed at the time. 



Although the same detailed. evidence is not traceable with regard 

 to the main junction (that of the Lower Sivaliks, or Nahun band, 

 with the slaty rocks of the mountains), it is certainly most reasonable 

 to apply to it the same interpretation as was proved in the less- 

 obscure section of the more recent boundary, and because whatever 

 features are seen in the former are common to both. I consider 

 that the older rocks had attained their present relative elevation 

 before the deposition of the Lower Sivaliks — that the present contact 

 of these rocks is the original one, only thrown out of its normal slope 

 by the yielding of the softer and less-weighted rocks to lateral 

 pressure. 



The longitudinal irregularities in both the lines of boundary de- 

 scribed are as numerous and as abrupt as those noticed in the Alps. 

 The coincidence between them and the great river-gorges is quite 

 accidental, there being more exceptions than examples of such a 

 rule. I could not observe a shadow of evidence for these steps in 

 the boundary of the mountains being due to cross faults or transverse 

 fissures. On the contrary, I have always found them connected with 

 local variations of strike, or of composition of the rocks, such as pre- 

 determine the irregularities in erery process of denudation. Thus 

 observation here seems to coincide with general considerations of 

 terrestrial physics in separating, or even opposing, the operations of 

 elevation and of contortion, the latter being altogether subsequent. 

 That the contorting force in the case before us came from the 



