1856.] Beport of the Magnetic Survey of India. 121 



We have been unable to find any traces of a cretaceous or numu- 

 litic formation in these parts of the Himalayas, the tertiary strata 

 of the Sutlej basin repose immediately upon the Jurassic formation. 



Valley of the Sutlej. 



17th. — The alluvial deposits which we meet after traversing the 

 sedimentary strata on the northern flanks of the Himalayas, do not 

 form an elevated plain bordering the Himalayas to the Northward, 

 as the plain of Hindustan does in the Southward ; they are merely 

 alluvial and lacustrine deposits, filling up the inequalities of one of 

 the largest longitudinal valleys of the world. On the other side of 

 the Sutlej, and of the Indus, new high mountain ranges rise covered 

 with snow, and very probably bearing glaciers, which evidently 

 belong to the same system of mountains. Looking from a high 

 station like Grunshankoerr peak near the Indus (19,640 E. I\) over 

 the Himalaya mountains to the South, and the long range of moun- 

 tains to the Northward, the mind is strongly impressed with an 

 idea of the unity of both mountain systems, in reference to orogra- 

 phical and geological structure. 



It is evident that the Himalayas form only one incomplete part 

 of the great mountain system of High Asia ; the numerous large 

 rivers descending from the Himalayas to the South into India, all 

 run through lateral transverse valleys, which might perhaps be 

 compared with regard to their position in the general mountain 

 system (though of course not with regard to magnitude) with the 

 numerous parallel transverse valleys running from the Pennine Alps 

 into the Rhone, or from the Tauern chain in the Tyrol into the 

 Salzach and the Draw. 



18th. The tertiary deposits in the basin of the Sutlej are of a 

 fluviatile and lacustrine nature ; they have been deposited in a large 

 fresh-water lake, probably formed by a rocky barrier, formerly exist- 

 ing at the place where the Sutlej now penetrates the Himalayas. 



"We found in them numerous fresh-water shells near Mangnang 

 and Tosing ; besides these they contain many remains of vertebrata 

 we were able ourselves in the neighbourhood of Mangnang to pick 

 out from the rock some of these fossil remains, and ascertained the 

 localities where others which we bought were procured. 



R 



