71 mallet: geology of darjiling and western duars. 



copper amounting, it is said, to 13 chataks per sir (jfths) of the 

 crude.* 



Altogether there are over a dozen localities in the Darjiling territory 



' Mode of occurrence of and the Western V™™ where indications of copper 



the ore * have been observed. The examination of these 



leads to some important generalizations. 1st. — With the exception of 

 some copper near Baxa in the rocks of the Baxa Series, all the known 

 copper-bearing localities are in the Baling beds. Some are, it is true, 

 situated in the transition rocks between the Dalings and the gneiss, but 

 none in the genuine gneiss itself. 2nd. — The ore in all is copper pyrites, 

 often accompanied by mundic. Sulphate, carbonate and oxide of copper 

 are frequent as results of alteration of the pyrites, but they occur merely 

 in traces. 3rd. — The ore occurs disseminated through the slates and 

 schists themselves and not in true lodes.f 



Mr. Piddington describes specimens of hornblende rock containing 



. ..,,. -r, iron pyrites with a trace of copper from the neigh- 



Copper localities. Pan- J 



kabari. bourhood of Pankabari.f I obtained a lump of 



clay-slate containing similar pyrites from the bed of the Bissarbatti 

 stream. 



In the bank of the Rani naddi, rather more than a mile above Rani 



Hat, a couple of trial excavations have been made 



Ram H-at (l). ^^ twenty yards apart. One is in quartz-schist, 



dipping north 15° west at 40°, through two or three layers of which, of 



* Bisman, the lessee of the Mangphu copper mine on the Tista, informed me that the 

 yield from the various operations at his mine were about as follows : —1 man (maund) of picked 

 ore yields 6 or 7 sirs of washed orej 7 sirs of washed ore yields 4 of regulus; 4 sirs of 

 regulus yields Jf sirs of copper, or about 3f to 4* per cent, of copper from the picked ore. 

 Eight or 9 sirs of regulus are obtained at one operation in about six hours, and 3 or 4 sirs 

 of copper in about three hours. These figures are not altogether reliable. 



f Mr. Taylor, a practical miner who examined a mine in the Mahanaddi valley 

 when it was at work, and whose report thereon is given in the appendix, speaks of the 

 ' lode' there. I believe, however, he must have used the word merely to express a metal- 

 liferous band of rock, without reference to its mode of origin. 



X Journal, Asiatic Society, Bengal, Vol. XXIII, p. 479. 



( n ) 



