1857.] Report on tlie Progress of the Magnetic Survey. 129 



Geology. 



9. The Kuenlueu on the 'one side an(T the Himalaya on the 

 other, form evidently only parts of one great system of elevation ; 

 Thibet is situated between them ; it is an undulating country, with 

 many high mountain ranges which are generally considerably lower 

 than the chains containing the culminating peaks of either the 

 Himalaya or the Kuenluen. Only in some parts, for instance in 

 the lacustrine basin of the Sutlej, Thibet assumes the form of an 

 elevated plain properly so called. 



10. The geological structure of the two above mentioned moun- 

 tain chains is closely allied, even the exterior features of the moun- 

 tains, in some parts of the Kuenluen about Mustak, are much 

 more similar to those of the Himalayas than might be expected. 



11. To the westward, the Himalaya and Kuenluen are sepa- 

 rated only by a very narrow belt of mountainous country, 30 to 50 

 miles broad ; it is composed of hornbleudic rocks and of a very nar- 

 row stripe of fossiliferous paleozoic rocks which are clearly inter- 

 posed between the elevated felspathic masses, which border them 

 to the north and to the south. 



The western termination of the Himalaya may be considered to be 

 at the great southern bend of the Indus. 



On the western side of the Indus the Himalaya and Kuenluen 

 cannot be traced as separate chains ; they form one mountain mass, 

 the elevation of which decreases very rapidly to the westward. 



I had the opportunity of examining a very considerable part of 

 these mountainous ranges from some elevated points in Astor, and 

 obtained much information about the topography of the countries of 

 Gilgit, Jassin, Chitroul and Mustak. 



Already in Jassin and Chitroul the mountains have lost, to a great 

 extent, their Alpine character ; there no longer exist any large gla- 

 ciers, and the Passes are all lower and many are even passable 

 during winter. 



Both in the Himalaya and Kuenluen, the central groups are 

 composed of felspathic crystalline rocks. Many of them show very 

 distinctly the fan-like arrangement of cleavage, which was first 

 observed in the Alps. 



8 



