CLUSTER ANALYSIS OF STRUCTURAL NITROGEN IMPURITIES IN SOUTHERN AFRICAN DIAMONDS: PLACER RELATIONSHIP WITH KIMBERLITE SOURCES

Relevance. The authors have developed the methodology for determining the sources of diamond-bearing placers, which clarifies the history of their development, the direction of diamond demolition and probable new areas of their accumulation. Along with paleogeographic studies of territories, this method will be able to significantly expand the understanding of the development of the history of diamondiferous areas in which both kimberlite pipes and placer deposits are located, and identify promising areas for their development. Objective: to determine the probable root sources of productive coastal marine and continental diamondiferous placers of southern Africa. Objects: a number of the largest diamondiferous placers of the Republic of South Africa and the largest diamondiferous pipes of southern Africa. Methods. Using cluster analysis, the authors studied nitrogen distribution in the diamonds of placers and pipes of southern Africa, identified the aggregates with the maximum coincidence of identical properties. Results. The authors developed the method for comparing nitrogen impurities in placer diamonds and root sources by a statistical method (cluster analysis). With the help of this technique, the probable sources of coastal and continental placers of the Republic of South Africa were determined. The findings were verified using another method of comparing placer diamonds and root sources, which confirmed the conclusions made. Recommendations are given for further improvement of the method (using a larger array of data, using data on diamonds from other regions, attracting data on other characteristics of diamonds). The history of erosion and demolition of diamonds from the root pipes, the formation of diamondiferous placers in the Cretaceous on the territory of the southern Africa was clarified, which opens up prospects for the discovery of large marine placers in the deep-water part of the mouth of the Oltfants River. In the future, the methodology can be used to study the history of the formation of diamondiferous placers in Russia and other diamondiferous regions of the world, to determine promising areas of exploration and development of these deposits.