GENESIS AND CRYSTALLIZATION OF ULTRAMAFIC ALKALINE CARBONATITE MAGMAS OF SIBERIA: ORE POTENTIAL, MANTLE SOURCES, AND RELATIONSHIP WITH PLUME ACTIVITY
N.V. Vladykin
A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, ul. Favorskogo 1a, Irkutsk, 664033, Russia
Keywords: Петрология щелочных пород, рудоносность, геохимия редких элементов и изотопов, мантийные источники, модель зарождения магм, Petrology of alkaline rocks, ore potential, trace element and isotope geochemistry, mantle sources, magma genesis model
Abstract
This paper discusses the genesis of large Siberian alkaline massifs hosting major ore deposits. These reference massifs are grouped based on the predominance of alkalies (K or Na) and their agpaitic index (miaskitic and agpaitic). We proposed new emplacement schemes for the Tomtor, Murun, Burpala, Synnyr, and Bilibino massifs supported by petrochemical and geochemical data, as well as new age estimates. Types of their ore potential and genesis of rare-metal mineralization are discussed. The formational types of carbonatites as the main ore-bearing rocks are given. The depth of magma generation and types of mantle sources are determined using isotopic data from previous studies. A model of plume-related generation of ultramafic alkaline magmas is proposed.
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