Доклады Академии наукДоклады Академии наук0869-5652The Russian Academy of Sciences1583510.31857/S0869-56524874424-427Research ArticleNew geochemical criterion of rare metal mineralization in the peralkaline magmas (Lovozero mineral deposit, Kola Peninsula)KogarkoL. N.<p>Academician of the Russian Academy of Sciences</p>kogarko@geokhi.ruVernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academу of Sciences2708201948744244272408201924082019Copyright © 2019, Russian academy of sciences2019<p class="a"><span lang="EN-US">Detailed studies have shown that changing the forms of eudialyte release (and the time of its crystallization) is a new geochemical criterion for the ore - bearing of alkaline magmas for rare metal (eudialyte ores). A new ore-bearing principle of alkaline magmas has been formulated: a prerequisite for the formation of an ore deposit is the early saturation of alkaline magmas with respect to the ore mineral. If the concentration of the ore component is significantly lower than the cotectic concentration (saturation), then the melt saturation and crystallization of the ore mineral will be carried out at the later stages of rock formation in a small volume of interstitial melt, when the phenomena of convective-gravity differentiation and segregation of mineral phases in the form of ore deposits are hampered. This leads to the dispersion of ore components in the form of xenomorphic forms of accessory minerals. Rocks of the differentiated complex (lower zone of the Lovozero deposit), and of the Khibiny massif, containing xenomorphic eudialyte, are not promising for eudialyte ores. Eudialyte deposits are associated with the upper zone of the Lovozero intrusion containing idiomorphic early eudialyte. The saturation of the initial magma in relation to eudialyte occurs after crystallization of about 80% of the intrusion. The proposed criterion is applicable to the largest alkaline massifs in the world. With the Ilimaussaksky massif (Greenland), in the rocks of which early, crystallized, idiomorphic eudialyte, there is a superlarge eudialyte ore deposit while in the Khibiny eudialyte ore is absent. </span></p>rare metal deposits of Lovozero massifeudialyte oremorphology of eudialyteeudialyte saturation of magmaЛовозёрское редкометальное месторождениеэвдиалитовая рудаформы выделения эвдиалитанасыщенность магмы эвдиалитом[Kramm U., Kogarko L. Nd and Sr Isotope Signatures of the Khibina and Lovozero Agpaitic Centers, Kola Alkaline Province, Russia // Lithos. 1994. V. 32. P. 225-242.][Герасимовский В. И., Волков В. П., Когарко Л. Н., Поляков А. И., Саприкина Т. В., Балашов Ю. А. Геохимия Ловозерского щелочного массива. М.: Наука, 1966. 392 c.][Kogarko L. N., Williams C. T., Wooley A. R. Chemical Evolution and Petrogenetic Implications of Loparite in the Layered, Agpaitic Lovozero Complex, Kola Peninsula, Russia // Mineral. and Petrol. 2002. V. 74. P. 1-24.][Parsons I. Origin of Igneous Layering. Dordrecht: Reidel, 1987. 561 p.][Когарко Л. Н., Лазуткина Л. Н., Кригман Л. Д. Условия концентрирования циркония в магматических процессах. М.: Наука, 1988. 120 с.]