340 Economic Geology of Assam. [No. 4L 



surface, but on digging through the sand, the water is found plenti- 

 fully, and smells strongly of muriatic acid, affording, when imme- 

 diately boiled in a small fiat dish, a residue of sharp tasted salt. 



Proceeding up the Namber river to the first falls, a distance of 

 about two miles, no rocks in situ are visible on either side, only 

 clays, and deposits of largish felspar rubble, the bed of the river 

 being small felspar gravel, holding a great quantity of black metallic 

 sand. In approaching the falls there are one or two springs, or 

 jalyes, on the West or left bank of the stream. The fall itself is 

 insignificant, being formed by a ridge of granite about 15 feet in 

 height, over which the river leaps. On the right bank the low hills 

 commence a short distance before reaching the falls, and in the bed 

 of the river immediately under these the different limestones for- 

 warded are found, together with the decomposing felspar rock, 

 affording the specimens, Nos. 4 and 5 of the list, together with hard 

 slaty clay, probably calcareous. The mass of granite forming the 

 fall passes from West to East, it does not look stratified in situ, 

 but some of the fragments break off like gneiss, and might be called 

 stratified granite ; it appears very durable, however, and not easily 

 broken. In colour and its component parts it looks much like the 

 red Aberdeenshire granite and takes a good polish ; the breaking 

 up of the slaty and stratified portions of the strata no doubt affords 

 the black metallic sand of the Namber and Kallianee rivers, and 

 both sands afford a good iron, if properly smelted. Immediately 

 above the fall, the bed of the river is one continued layer of large 

 boulders, which, however, have not been examined, but most probably 

 they belong to the granitic formation. Einer, and larger falls are said 

 to exist two days' journey further up the Namber river, but they 

 are not very accessible. I have failed to find any traces of gold in 

 the metallic sands of the Namber river. The sands of the Dhun- 

 seree river, however, and particularly below the mouth of the Kal- 

 lianee river (which rises in the same range of hills as the Namber) 

 contain gold according to native account, also the Kallianee river 

 was in former times considered a prolific gold stream, the washings 

 having been carried on close under the hills. 



26. Decomposing granite rocks, Sfc. —High bank of Brahmaputra 

 at Choonpoora. In the high bank of the Brahmaputra at Choon- 



