1854.] STRACHEY PHYSICAL GEOLOGY OF THE HIMALAYA. 249 



Recent experiments, made on the gossaniferous quartz from this 

 locaUty, have shown that it is not merely auriferous, but, in some small 

 portions at least, highly so. I forbear, however, giving the result of 

 experiments which are yet, as to their scale, insignificant ; and also 

 because I am glad that our Society is, by the existence of a compe- 

 tent governmental department, quite relieved from all social respon- 

 sibihty as to the economics of the question. Here we may pursue 

 our researches in descriptive or theoretical geology with true philo- 

 sophic tranquillity, undisturbed by the harsh cry of 'cui honoV which 

 so often and so usefully checks us elsewhere. 



3. On the Physical Geology of the Himalaya. By Captain 

 Richard Strachey, Bengal Engineers, F.R.S., F.G.S. 



[Abstract.] 



The author having, in a previous communication to the Society*, 

 described the geological structure of a part of the Himalaya moun- 

 tains, in the present paper he proposed to complete that sketch, at 

 the same time taking a rather larger field of view, offering some ex- 

 planation of the manner in which the chain in general had been 

 raised to its present position — first, with reference to the mechanical 

 action of the forces in operation ; and secondly, as to the epochs at 

 which the upheavement took place. 



Attention was first directed to some of the more prominent points 

 of the physical structure of the great mountain mass, of which the 

 Himalaya forms a portion. Among these were specially noticed : — 

 1st. The general form of the section of the mass, which shows that 

 the Himalaya mountains are merely the southern slope of a great 

 protuberance, the summit of which forms the table-land of Til^et, 

 while the northern slope is a mountainous region, marked on our 

 maps as the Koneulun, similar to the Himalaya, and terminating in 

 the great plains of Central Asia. 2nd. The parallelism to one an- 

 other, and to the outer edge of the mountain area, of the great ridges 

 or lines of elevation ; of the great valleys or lines of drainage, which 

 are also lines of rupture ; of the strike of the strata ; of the lines of 

 igneous action ; and of the distribution of the various deposits, con- 

 sidered both in reference to their mineral character and geological 

 age. .3rd. The arrangements of the drainage, in accordance to which 

 the crests of the northern and southern slopes of the great mass form 

 two main lines of water-shed, proposed to be termed the " Turkish 

 and Indian Water-sheds," to the north and south of which, respect- 

 ively, the rivers flow off directly to the plains of Turkistan on the 

 one side, and to those of Northern India on the other ; while the 

 waters of the summit of the table-land are collected into two streams 

 alone, the Brahmaputra and the Indus, which are discharged from 



* Quart. Journ. Geol. Soc. vol. vii. p. 292. 



