PETROCHEMICAL DIVERSITY OF TRAPSON THE EASTERN PERIPHERY OF THE TUNGUSKA SYNECLISE
M.D. Tomshin, A.G. Kopylova, and O.A. Tyan
Institute of Diamond and Noble Metals Geology, Siberian Branch of the RAS,39 prosp. Lenina, Yakutsk, 678980, Russia
Keywords: Tholeiitic magma, differentiation, traps, sills, magmatites, dolerites, ophitic and poikilophitic textures, petrochemical type
Pages: 73-84
Abstract
Results of petro- and geochemical study of traps in the basin of the Morkoka-Markharata River are reported. The traps are compared with Permo-Triassic basites from other regions of the Siberian Platform. Permo-Triassic trap intrusions in the eastern Tunguska syneclise are made up of three petrochemically different types of basic melts. They successively intruded during the same tectonomagmatic cycle. Each of the intrusive groups has its proper geochemical specifics originated during the magma generation and preserved throughout evolutionary transformations up to the emplacement of magma in a modern chamber. This specifics does not depend on the volume of intruded melt, scale of intrachamber differentiation in the intrusions, character of transformation of magma during its deep-level fractionation on the path to a modern chamber, and position of the intrusions relative to magma control zones within the Tunguska syneclise.
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