Saint Petersburg State University (Russia):

Semikolennykh Ye. S., Postgraduate

Petrov S. V., Head of Chair, Associate Professor, Ph. D. in Geology and Mineralogy, petrov64@gmail.com

The article presents the results of platinumbearing chromitites material composition, occurring in the UG-2 horizon in the Eastern sector of the Bushveld massif. Mineral associations and chemical composition of the horizon's rocks in the areas under preparation for development throughout the arch of Eastern sector from north to south (more than 100 km) are established. The most productive platinum mineralization is characterized by prevalence of Pd over Pt, increased share of low-melting platinum group elements, differs by association with Cu and Ni and dated to chromitites with thinner thickness. On the basis of the ontogeny analysis three types of chromespinels are distinguished, formed consecutively in the course of time, with various extent of occurrence along the Eastern sector. The features of chemical composition of plat inum group minerals and their distribution are defined for the first time with respect to the studied sites of the UG-2 horizon of Eastern sector. The spatial confinement of platinum mineralization to early chromespinels' types and palladium — to later chromites is revealed. The data obtained with regard to chromespinels may be of a theoretical interest with respect to platinum-group metals ore genesis in association with maficultramafic mineralogenic systems such as Bushveld and other similar complexes, as well as of a practical interest in the way of fore casting, exploring and assessment of new platinum metals ore deposits and also solution of technological tasks of ore beneficiation. The results of the investigation indicate that chromitites of the northern sites of Eastern sector are more promising in relation to platinum mineralization and easier-processed.

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