ABOUT ANCIENT SOURCES OF DIAMONDS PLACERS

Abstract

Basing on generalization of large actual material on complex investigation of diamond, its characteristic in Upper Paleozoic and Mesozoic sedimentary thick layers of the Siberian platform has been provided. It has allowed receiving new data on composition features and distribution of diamond in recent sediments of main diamondiferous regions of Lena-Anabar, Central-Siberian and Tungusskaya sub-provinces. On the north-east of Siberian platform, the region of Kyutyungdinsky graben and nearby territories, perspective for the discovery of rich kimberlite bodies with specific dia- monds, are of the most interest. Special attention has been paid to the Central-Siberian sub-province, where it has been convincingly shown that the area of development of individual diamond macro- associations is limited by a specific diamondiferous region, within which complexes of different in age terrigenous and coastal Upper Paleozoic and Mesozoic sediments are developed. The complex of features of diamonds from placers of the described platform testifies by morphology, coloration, hard inclusions, internal structure, photoluminescence and admixture composition about plurality of primary sources and availability of still undiscovered kimberlite bodies within many diamondiferous regions. Application of typomorphic features of crystals for restoration of exogenous history of diamonds on the path from primary sources to the sites of modern allocation in placers, as well as for paleogeographical reconstructions of distribution of ancient productive thick layers and clarification of diamondiferous material drift direction, has a significant importance. Proximity of typomorphic features of diamonds in sedimentary thick layers of these ages, identified in some diamondiferous regions, testifies about formation of these collectors due to washout of more ancient productive layers or Middle Paleozoic primary sources. Polygeny of mineralogical associations of diamonds from different in age placers within some diamondiferous regions has been noted, which may be successfully used when forecasting and prospecting primary sources of the mineral.