EXCURSION •
NKOMATI NICKEL MINE REVISITED
By Dr Nicolaas C Steenkamp
Nkomati mine was South Africa ’ s only primary nickel mine and has now been placed on care and maintenance . Dr Nicolaas C Steenkamp took a drive past to see how the landscape has changed and to revisit its potential .
Hidden between the pine tree plantation on the Eastern Escarpment between the towns of Badplaas and Barberton , is the Nkomati Nickel Mine . The winding road that leads down to the mine has long been a favoured route for motorcycle enthusiasts . It provides scenic bends down the escarpment through the grasslands of the Highveld to the plantations established in recent years , offering a panoramic view of three open pits and surface mine infrastructure .
The Nkomati Nickel Mine was developed in the Uitkomst Complex , indicated to represent a conduit ultra-mafic deposit associated with the Bushveld Complex . The Uitkomst Complex intruded between the chemical dolomite and clastic shale sediments of the Transvaal Supergroup and basement granite . Weathering resulted in the partial exposure of the conduit along the escarpment . The Uitkomst Complex consists of a layered succession of up to 8km in length , with a thickness of up to 800m .
Original mining started with gold mining on the farm Little Mamre , which also gave its name to the mining operation . The gold mining operation was , however , short lived and it took several years before the layered mafic intrusion gathered enough interest to start a deep exploration drilling program . The presence of a massive sulfide orebody on contact between the intrusion and the basement rock initiated the underground mining operations with the sinking of a vertical shaft to access the orebody .
The Uitkomst Complex was unique in terms of the range of mineralisation that it presented . The sulphide mineralisation hosted nickel , platinum group minerals ( PGMs ) and copper mineralisation . The massive sulphide orebodies were developed and this was the first target of the underground mining . The lower portion of the Uitkomst Complex also hosted the Main Mineralised Zone ( MMZ ) of disseminated and semi-massive suphides . This was overlain by the chromatiferous-peridodite mineralised zone ( PCMZ ) that contains both disseminated
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