THE KARELIAN-KOLA MEGACRATON ZONING ON TYPES OF DIAMOND PRIMARY SOURCES

V. N. Ustinov 1, L. P. Lobkova 1, I. M. Kukuy 2, M. G. Antashchuk 1, E. V. Nikolaeva 1

1 Сentral Research Institute of Geological Prospecting for Base and Precious metals, Saint-Petersburg, Russia; 2 AK ALROSA, Saint-Petersburg, Russia

The zonation of the north-western part of the East-European province on types of diamond primary sources was carried out on the basis of the complex study of trains and haloes of dispersion of kimberlite indicator minerals (KIMs) within the Karelian-Kola megacraton (subprovince). The detailed study of typomorphic features of KIMs from polyfacial sediments has shown that within the Karelian-Kola subprovince, the dispersion trains of diamond-bearing rocks formed as a result of erosion of host rocks of different types: kimberlites, lamproites, deep ultrabasic and basic rocks, including related ones (lamprophyres, picrites, komatiites, etc.). Despite the heavy mineral sampling, the central part of the Karelian craton is characterized by the full absence of KIMs, which indicates low probability of discovery of diamond primary sources there. The morphogenetic analysis of dispersion haloes of KIMs shows the existence of areas promising for discovery of diamond-bearing rocks in the north-western part of the East-European province. The recommendations and the study experience provided can be useful in diamond prospecting at various areas of the Siberian Platform.

Keywords: megacraton, kimberlites, zoning, trains, dispersion haloes.

DOI 10.20403/2078-0575-2017-4-51-61

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