GEOLOGY AND MINERAL EESOURCES OF SIKHIM. 69 



4. Eonglichu. — About three miles* east-north-east of the Rong- 

 lichu rest bungalow, at the junction of a stream coming down from 

 Pangola with the Ronglichu, I picked up a few pieces of schistose 

 quartzite in which copper pyrites and bornite (?) are disseminated 

 along foliation planes. I did not find the ores in situ. I have no 

 doubt they occur some distance up the stream towards Pangola. In 

 this case the ores occur in the heart of the gueissose group, 



5. Lindok. — About half-way on the new road between Gantok 

 and Tumlong, close to the village of Lindok, there occurs interstrati- 

 fied with gneiss, talcose schists with pyrite, chalco-pyrite, bornite, 

 copperas and blue vitriol with small traces of epsomite. The thick- 

 ness of the cupriferous band in a stream just by the road was found 

 to be about 2 feet, and it was traced for about 38 feet : dip 40° 

 ENE. A little to the south-east of the stream, also by the road, 

 there is similar schist with copper ores in the gneiss, but the thickness 

 here is not more than 7 inches. 



6. Bhotang. — Situated about 6 miles east-south-east of Pachi- 

 khani, close to the junction of the Tista and the Rungpo, along a 

 precipitous scarp of slaty rocks overlooking the Tista. The mines 

 here were worked for about 20 years and abandoned only last year. 

 Lachmi Das, proprietor of Pachikhani, was the lessee. The average 

 annual outturn was about 300 dharnis, or 225 maunds of copper. 

 The ore as usual is chalco-pyrite, occuri'ing in a hard jaspery-looking 

 rock ; but it is much mixed up with iron pyrites, more so than at 

 Pachikhani. There are two ore-bands parted by 10 or 12 feet of 

 slaty shales, which too are more or less impregnated by ore. Of 

 these two bands, the upper averages about 3 feet in thickness, and 

 the lower 2 feet 6 inches. They run parallel to bedding and appear 

 to be what are called segregated veins. The dip is about 45° E. to 

 ESE. Levels are driven along the courses of the ore-bands. One 

 I entered has gone for about 54 feet and then stopped owing to water 

 filling in. If the water were let off, there is no reason why the ore 

 should not be found workable deeper down. 



The ore-bands can be traced with the eye for some 200 feet 

 along the strike on the north side. South of the levels they run 

 for about 25 feet, and are then faulted against greyish and greenish 

 soft slaty shales dipping north-eastward. On the south side of the 

 fault the ore-bands are met with at a height of about 100 feet above 

 those on the north side. 



An average sample from the old working yielded on assay 12-21 

 per cent, of copper. 



* It may be obseired that distancos throughout this paper are measuied as the crow flies. 



F 2 



