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11.
N. V. Gorelikova F. V. Balashov Ya. V. Bychkova E. A. Minervina P. G. Korostelev O. L. Magazina N. S. Bortnikov 《Doklady Earth Sciences》2016,467(2):355-359
The distribution of REEs and some minor elements in tourmalines of different associations and deposits of the Russian Far East is studied by the methods of ICP-MS, ICP-MS with laser ablation and scanning electron microscopy. The duality of REE speciation in tourmaline is established: in high-temperature varieties, most REEs (mainly HREEs) are incorporated in rare minerals (monazite, xenotime, zircon, and F–Ce–Y carbonate), whereas hydrothermal ores are characterized by isomorphic incorporation of LREEs in the mineral structure, as well as by a fine admixture of zircon at the expense of detrital clasts in flyschoid rocks with the zones of tourmalinization. 相似文献
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T. V. Rundkvist Yu. A. Balashov S. G. Skublov P. V. Pripachkin R. A. Grebnev 《Geology of Ore Deposits》2016,58(7):525-535
The paper presents data on the geochemical and geochronological characteristics of zircons from mafic rocks of part of the Monchegorsk layered complex represented by the Vurechuaivench massif. Ages of zircons (SHRIMP-II) from samples V-l-09 (anorthosite) and V-2-09 (gabbronorite) are dated back to 2508 ± 7 and 2504 ± 8 Ma, respectively. The chondrite-normalized REE patterns confirm the magmatic nature of zircons. The data unequivocally indicate that the U–Pb age of zircon from both gabbronorite and anorthosite corresponds to the age of melt crystallization in a magmatic chamber. The mantle origin of gabbroic rocks of the Vurechuaivench massif is confirmed by the REE patterns of three zircon generations with different crystallization sequences. The wide range of the Ce/Ce* ratio (9.96–105.24) established for zircons from gabbroic rocks of the Vurechuaivench massif indicates sharply oxidative conditions of zircon crystallization. For deepseated mantle rocks, these data can only be explained by significant contamination of the melt with country rock material. 相似文献
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Boeva N. M. Slukin A. D. Shipilova E. S. Makarova M. A. Balashov F. V. Zhegallo E. A. Zaytseva L. V. Bortnikov N. S. 《Doklady Earth Sciences》2021,500(1):720-727
Doklady Earth Sciences - The mineral and chemical composition of bauxites from the Chadobets uplift of the Siberian Platform is the total product of laterites on aluminosilicate rocks (source of... 相似文献
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Yu. A. Balashov 《Petrology》2009,17(1):90-100
Systematization of information on multivalent trace elements in peridotite xenoliths made it possible to reveal differences in the distribution of these elements in the subcontinental and suboceanic segments of the lithosphere, which reflects the development of a geochemical heterogeneity in the lithosphere during the early (Hadean) stage of its evolution. The vast extent of trace-element differentiation in Hadean peridotite xenoliths is most probably explained by the appearance of appreciable masses of condensed water and, consequently, active mantle metasomatism in the hydrated lithosphere. The latter formed the upper depleted (oceanic) zone underlain by an “undifferentiated” zone enriched in trace elements. The removal of trace elements from both zones, a process that does not rule out the participation of earlier accretion in it, gave rise to a crust strongly enriched in these elements. The existence of long-lived extensive lithosphere heterogeneity calls for revision of the concept of multistage crustal growth with a general tendency toward an increase in its bulk volume. 相似文献
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L. V. Tverskaya S. V. Balashov N. N. Vedenkin V. V. Ivanov T. A. Ivanova D. S. Karpenko S. G. Kochura I. A. Maksimov N. N. Pavlov I. A. Rubinstein M. V. Tel’tsov D. A. Trofimchuk V. I. Tulupov V. V. Khartov 《Geomagnetism and Aeronomy》2008,48(6):719-726
Increases in solar protons and variations in the electron and proton fluxes from the outer radiation belt are studied based on the GLONASS satellite measurements (the circular orbit at an altitude of ～20000 km with an inclination of ～65°) performed in December 2006. Indications in the channels, registered protons with energies of Ep = 3–70 MeV and electrons with energies of Ee > 0.04 and >0.8 MeV, are analyzed. The data on electrons with Ee = 0.8–1.2 MeV, measured on the Express-A3 geostationary satellite, are also presented. Before the strong magnetic storm of December 14 (|Dst|max = 146 nT), the maximum of the outer belt electrons with the energy >0.7 MeV was observed at L ～ 4.5. After the storm, the fluxes of these electrons increased by more than an order of magnitude as compared to the prestorm level, and the maximum of a “new” belt shifted to L < 4 (minimal L reached by the GLONASS orbit). Under quiet geomagnetic conditions, solar protons with the energies >3 MeV fill only high-latitude legs of the GLONASS orbit. During the strong magnetic storm of December 15, the boundary of proton penetration into the magnetosphere almost merged with the orbital maximum of the proton radiation belt. 相似文献