Abstract

Exploration for platinum-group elements along the southeastern sector of the eastern Bushveld Complex has led to the discovery of Transitional Unit and Upper Critical Zone lithologies which contain the important Merensky Reef and UG 2 layers on farms Kliprivier, Klipbankspruit, Houtenbek and Mapochsgronde, and Platreef-style mineralization near the base of the intrusion south of the Lagersdrift fault. The area, located in the Mpumalanga Province, constitutes one of the least-explored portions of the intrusion. Since the drilling programmes during 1967 to 1987 in the Kliprivier area and those in the vicinity of Bethal in 1970, this sector has received little attention, and its characteristics have gone largely undocumented because it was mined only for and considered a source of vanadiferous magnetite and dimension stone.

The results of drilling in the Kliprivier area suggest that the UG 2 chromitite appears atypical, and grades are of low to medium quality with values up to 5.43 g/t 3PGE + Au over 2.17 metres. Most Merensky Reef intersections in this area are also atypical of those seen to the north. Intersections of sulphide-mineralized units in the Bethal area, that are believed to belong to the Upper and Lower Zones, were in the past not considered to be economically significant.

The increased demand for platinum has led to renewed interest in the southern extensions of the eastern Bushveld Complex. This interest has probably also been triggered by the discoveries on the Everest South property (UG 2), just north of Kliprivier. Eurasia was the first of a group of middle-tier companies to obtain permission to investigate the area and to secure mineral rights on Kliprivier.

This study presents new field, soil-geochemical, chemical, strontium-isotope, electron microprobe and geophysical data, which reveal the presence of the Upper Critical Zone along the basal contact of the mafic rocks with the Transvaal Supergroup. The geology of the area also shows some analogies to portions of the northern limb. A brief review of the estimates of inferred resources for the area is presented.

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