COPPER. 105 



stone or the eruptive rock. They are very numerous, but distri- 

 buted in such an irregular way, that large scale operations are out 

 of the question. (La., pp. 411-413 and D., p. 248). 



Lao-tchou-chan is a village in the valley of the Ta-chaing Ho, 



east of the city of OhYMig-chiang Fu. There 



fcjs£?x l r (CV are tw ° mines ' ° ne tothc north and the ° thor 



to the south of the village. They are both in 

 Cambrian slates and limestones. At the southern mine of 

 Pe-mao-tehang there is a small system of workings in the slated 

 on a number of scattered calcite veins containing copper pyrites. 

 The deposit is not interesting. The northern mine, called 

 Ouan-pao-tong, displays a small vertical fracture in limestone 

 containing a vein three or four cms. thick and containing copper 

 minerals. It thinned out in a distance of three or four metres 

 to a pure calcite stringer. The region is very broken up and the 

 strata contorted and cracked. It is considered that there is little 

 chance of finding important fractures, but rather small cracks 

 without any continuity which are sometimes mineralised. Lantenois 

 concludes that all the copper mines he visited in Eastern 

 Yunnan belong to the disseminated type. (La., p. 414). 



Copper Mines of North-Eastern Yunnan, described by Laclcre and 



Deprat. 



Leclere visited the important copper-producing district of Tung- 

 ch'uan Fu in 1898; Deprat in 1910. The following notes are from 

 their works. 



This mine is in Carboniferous porphyries. One of the flows 



contains a horizontal band of barytes carrying 

 uan Fu P0 Ul l en"e.)" native copper and its oxides. Workings are 



started on the flank of the hill at points where 

 the barytes layer is thick enough to permit the driving of a low 

 adit without breaking into the igneous rock. The deposit 

 is certainly a rich one and work was only commenced in 1897. It 

 is difficult to come to any conclusion about its actual value because 

 the thin portions of the deposit are not worked, though they con- 

 tain as much mineral as the others. Masses of native copper 

 too large to be brought out of the workings are left behind. About 

 100 men are employed. The picked ore contains 20-40 per cent. 

 of copper. It is taken to Tung-ch'uan Fu where it is bought by 

 the officials at about 170 francs per metric ton, including 20 francs 



H 



