THE INSIZWA COPPER-NICKEL DEPOSITS. 



By John George Rose, F.C.S. 



The occurrence of copper in the Insizwa Mountain, near the 

 village of Mount Ayliff, Griqualand East, was known some 

 twenty years ago. Many half-hearted and wholly inefficient 

 attempts were made to prove the extent and value of the de- 

 posit, but no work worthy the name w^as done until it was 

 discovered, some five or six years ago, that nickel occurred 

 along with the copper. In spite of the fact that this was really 

 (in view of the Mond patents) an asset of doubtful value, the 

 •discovery of this metal seemed to give new life to prospecting 

 operations in these regions and, for the first time since the 

 discovery of copper there, a well-directed attempt to follow 

 the lodes was begun. A friend of the author's brought him 

 some hand specimens about June, 1908, and while assaying 

 these for precious metals it was found that platinum was pre- 

 sent in appreciable quantity. The author was at that time busy 

 investigating a few problems connected with platinum, so his 

 interest was keenly aroused and as the result of a confidential 

 report on the subject to his Minister he was instructed to visit 

 the mines and report fully upon them to the Government. The 

 journey from Cape Town to Insizwa is long and tedious. The 

 route followed was via D' Urban, thence through Alexandra 

 Junction and Esperanza Junction to Sheartstown (Ixopo), 

 where the railway was left behind and post carts, private carts 

 and horses were requisitioned to complete the journey, via 

 Umzimkulu. Kokstad, and Mount Ayliff, to the Insizwa Com- 

 pany's workings. These are situated, amid the most charming 

 scenery, on the southern slope of the Insizwa Mountain, where 

 the Waterfall Gorge affords facilities for driving adits along 

 the deposits of ore. These occur along the line of contact of 

 dolerite and shales, some 4,000 feet above the sea level, the 

 metals being present as sulphides. 



The contact dips north into the mountain at an angle of 

 about 30°. Its outcrop is fairly well defined, and it has been 

 traced from Ndakeni on the west, through Nolangeni, to the 

 Ingeli Mountain on the Natal Border 30 miles east. Where- 

 ■ever it has been opened it has been found to carry copper and 

 nickel, the mineralisation always occurring in the dolerite and 

 not in the shale. Travelling in these parts during the rainy 

 season is a matter of considerable difficulty, so that the author 

 was not able personally to trace the contact as far as Ingeli 

 as time was pressing. Most of his time was spent on the 

 Insizwa Company's property, where a great deal of useful 

 work had been done. This Company took over the rights of 

 the old South Namaqua Company, whose unproductive and 

 ill-advised workings are still to be seen. Originally along the 

 contact between dolerite and shales the Insizwa Company has 

 laid bare some rich bodies of Pyrrhotite (Fe„S„+,), and 

 Pentlandite (FeNiS), which ought to pay handsomely 

 for their working — given railway facilities to the coast. 

 The deposits therefore closely resemble the famous Sudbury 



