1848.] Metalliferous deposits in the Sub -Himalayas. 139 



under enormous pressure ; when the most subtile gasses must have 

 been liquids or even solids ; that the metals were reduced to oxides or 

 sulphurets, from hitherto unknown matrices, and distributed in veins 

 throughout the granular masses ; and thus when along with them up- 

 heaved by volcanic forces, portions were reduced to the metallic state, 

 especially the gold, when again exposed to intense heat, under a pres- 

 sure that permitted the gasses to escape. 



It will be seen from the nature of the gneiss of the Himalaya 

 range, in which Darjeeling is situated, that similar forces have been 

 even more recently at work, and reasoning a priori, we may conclude 

 that only want of proper exploration, has prevented the discovery of 

 metalliferous veins. 



It is clear that the most easy source of all gold deposits is alluvial ; 

 a natural effect imperfectly imitated in obtaining the pure metal, from 

 the solid granite ; and in all countries where gold is found, in alluviae, 

 these are of course first exhausted before search is made in harder mate- 

 rials, through the original source. In that portion of the Himalayan hills 

 however now spoken of, no gold or other metal can be expected to be 

 found in the alluviae so generally covering them ; as that alluvia must 

 have been deposited at a time when the gneiss forming their mass, was 

 horizontally stratified, at a probable great depth, under superimposed 

 fresh water, and when no great hills existed, from which metalliferous 

 detritus could have come. In a similar way, even if gold does exist in 

 the lower ranges, that metal will not be found in the alluviae of the 

 minor rivers, owing to their rapid changes and sporadic distribution. 



In the vast alluvial deposits containing gold in other countries, the 

 torrents of the surrounding hills have for thousands of years, poured 

 them down, while natural basins existed to retain them, and this forms 

 one great difference of feature between the Himalayas, as yet known, 

 and the Andes. 



On the whole southern side of the Himalayas, as yet explored, no 

 elevated plains are known to exist, while amidst the declivities of the 

 Cordilleras, plains are often presented of immense altitude, completely 

 level, and of vast extent, and which have retained the gold and other 

 heavy deposits, washed down from the mountains. 



On the northern and Thibet side of the Himalayas, similar vast 

 plains occur ; and amidst these very thinly inhabited and hardly 



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