SPECIFIC FEATURES OF DIAMONDS FROM MODERN PLACERS ON TERRITORIES OF ASSUMED DISTRIBUTION OF ANCIENT PRODUCTIVE MATERIAL SUPPLIERS

Results of complex investigations of typomorphic features of diamonds from modern placers and occurrences of Tungusskaya diamondiferous sub-province (TDS) allowed distinguishing individual diamondiferous areas, regions and fields in the southern part, for which types of original ­sources and level of their potential ore content may be forecasted. The length of placer occurrences and placers of modern age in TDS, formed mainly due to erosion and redeposition of different in age ancient collectors, which usually go out beyond the diamondiferous region, may exceed hundreds of kilometers. Among the diamonds in these placers rounded diamonds of the Ural (Brazil) type, practically absent in high-productive bodies of the Siberian platform (SP), constitute a significant part. One should note polygeny of mineralogical associations of diamonds from modern placers of the SP south within individual diamondiferous regions with broad occurrence of placer diamondiferousness, reaching increased concentrations together with diamond occurrences of carbon age (Tychansky, Tarydaksky and Shushuksky haloes). Utilization of typomorphic features of crystals for reconstruction of exogenous history of diamonds on the way from their sources to the places of modern location in placers has important significance, which will allow receiving new evidence about directions of diamondiferous material drift.