ABOUT EFFICIENCY INCREASE OF PROSPECTING WORKS ON DIAMONDS

Zinchuk N.N.

West-Yakutian Scientific Center of RS (Y) AS, Mirny, Russia, nnzinchuk@rambler.ru

 

    In spite of comparatively long study of primary diamondiferousness of the World ancient platforms (Siberian, East-European, African et al.), a number of questions for each of them require additional investigations. Thus, for instance, the problems of primary sources on prospective territories of Irkutsk area and Krasnoyarsk krai, diamonds of “Abelyakh” type, reasons of different kimberlite fields’ productivity of Anabar and Vilyuy subprovinces, related with unified protolith may be referred to the number of such unsolved issues for the Siberian platform. Voluminous materials, pertinent to radiometric dating of diamondiferous and potentially diamondiferous magmatites, role of faults, avlakogenes, geophysical characteristics of different in prospectivity areas and kimberlite fields of main subprovinces, require serious reasoning. Complex additional analysis is required of long-standing conceptions about epochs of the Siberian platform kimberlites formation, of which only Middle Paleozoic and, with big proviso, Triassic epochs are recognized as practically significant. At this general decrease of productivity from the center of province to periphery is noted, which is explained by different reasons. At the same time, for instance, on African platform there are no industrially non-diamondiferous time intervals of kimberlite-formation, though their number corresponds to such ones on the Siberian platform. Basing on the analysis of general position of diamondiferous and non-diamondiferous kimberlites we considered the process of productive magmatites’ formation within the Siberian platform by time sections-stages of Palaeogaea and Neogaea, making it possible to see that individual parts of a diamondiferous region are found in these or those time intervals in different historic-mineragenetic provinces (HMP). Their spatial superposition reflects migration of kimberlite-formation in space and time with the detail which is allowed by modern level of our knowledge. By “historic-mineragenetic provinces” we mean the areas of continents and oceanic basins of the Earth with mass occurrence of ore and non-ore material accumulations, formed in the course of a certain historic-mineragenetic stage. In order to increase efficiency and completeness of the Siberian platform territory prospecting we recommend to enhance investigations within the following historic-mineragenetic provinces (HMP): Early-Late-Pre-Cambrian (Aldan, Ust’-Lena and Near-Yenisey HMP), Riphean (Anabar-Olenek, Angaro-Tungusskaya and Aldan-Stanovaya HMP), Early-Paleozoic (Vilyuy and Anabar-Olenek HMP), Early-Hercynian (Vilyuy, Angaro-Olenek and Angaro-Tungusskaya HMP), Late-Hercynian (Anabar-Olenek and Angaro-Tungusskaya HMP), Kimmerian (Nizhnelenskaya and Aldan HMP, lamproites and kimberlites of Northern Taimyr), Early-Alpine (Nizhnelenskaya and Aldan HMP) and Late-Alpine (Nizhnelenskaya and Aldan HMP), which can complement data about diamondiferousness of these periods, together with discovered primary high-diamondiferous deposits of Middle-Paleozoic age. The importance of this idea is confirmed by kimberlite belonging of the recently discovered high-diamondiferous Nakyn field of Middle-Markha region of a new for the Siberian platform Early-Paleozoic epoch of thick crust-formation and kimberlite magmatism. And today this region, with already discovered pipes Botuobinskaya, Nyurbinskaya and body Maiskoye – is the most perspective both for prospecting of new primary and placer deposits, and for their industrial development. This gives hope that within the province, so much similar by geological structure to African platform, with time diamondiferous bodies of other kimberlite-formation epochs will be discovered. Besides mentioned above perspective different in age historic-mineragenetic provinces, one should pay special attention to investigation of a number of prospective territories and sites, in particular, Lower-Carboniferous and Triassic deposits of the Siberian platform north-east, which may lead to discovery of primary sources, not traditional for platform ages.