| Инд. авторы: | Rokosova E.Y., Panina L.I., Vasil'ev Y.R, Lesnov F.P. |
| Заглавие: | Conditions of crystallization of olivine shonkinites in the Inagli massif (Central Aldan) |
| Библ. ссылка: | Rokosova E.Y., Panina L.I., Vasil'ev Y.R, Lesnov F.P. Conditions of crystallization of olivine shonkinites in the Inagli massif (Central Aldan) // Russian Geology and Geophysics. - 2016. - Vol.57. - Iss. 9. - P.1298-1311. - ISSN 1068-7971. - EISSN 1878-030X. |
| Внешние системы: | DOI: 10.1016/j.rgg.2016.08.015; SCOPUS: 2-s2.0-84990233791; WoS: 000384545500005; |
| Реферат: | eng: The olivine shonkinites localized among dunites and alkali gabbroids in the northern part of the alkaline ultrabasic Inagli massif (northwestern part of Central Aldan) have been studied. The obtained data on the chemical and trace-element compositions of the rocks and minerals and the results of melt inclusion study showed that the olivine shonkinites crystallized from alkaline basanite melt enriched in Cl, S, CO2, and trace elements. Clinopyroxene crystallized at 1180-1200 degrees C from a homogeneous silicate-salt melt, which was probably separated into immiscible silicate and carbonate-salt fractions with temperature decreasing. The composition of the silicate fraction evolved from alkaline basanite to alkaline trachyte. The carbonate-salt fraction had an alkaline carbonate composition and was enriched in S and Cl. The same trend of evolution of clinopyroxene-hosted melts and the igneous rocks of the Inagli massif suggests that the alkali gabbroids, melanocratic alkali syenites, and pulaskites formed from the same magma, which had a near-alkaline basanite composition during its crystallization differentiation. The geochemical studies showed that the olivine shonkinites and glasses of homogenized melt inclusions in clinopyroxene grains have similar contents of trace elements, one or two orders of magnitude higher than those in the primitive mantle. The high contents of LILE (K, Rb, and Sr) and LREE in the olivine shoshonites and homogenized inclusions suggest the enriched mantle source, and the negative anomalies of HFSE and Ti are a specific feature of igneous rocks formed with the participation of crustal material. The slight depletion in HREE relative to LREE and the high (La/Yb)(n) ratios in the rocks and inclusion glasses (10.0-11.4 and 4.7-6.2, respectively) suggest the presence of garnet in the mantle source. (C) 2016, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.
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| Ключевые слова: | MINERALS; INCLUSIONS; SILICATE; UPPER-MANTLE; SULFATE MELTS; CARBONATITE MELTS; LIQUID IMMISCIBILITY; MAGMA; Inagli massif; sources of magmatism; geochemistry of rocks and melt inclusions; immiscibility of melts; silicate-carbonate inclusions; olivine shonkinites; PIAN-DI-CELLE; GENESIS; |
| Издано: | 2016 |
| Физ. характеристика: | с.1298-1311 |