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41.
S. B. Lobach-Zhuchenko V. V. Balaganskii M. Yu. Koreshkova K. I. Lokhov Sh. K. Baltybaev L. M. Stepanyuk Yu. S. Egorova S. A. Sergeev I. N. Kapitonov O. L. Galankina E. S. Bogomolov N. G. Berezhnaya V. V. Sukach 《Doklady Earth Sciences》2017,474(2):700-705
This report presents data on the geological structure and location of the orthopyroxenite inclusion in gneissic enderbites of the Bug granulite–gneiss domain. Three stages of orthopyroxenite formation were identified on the basis of studies of the mineral composition along with the U–Pb and Lu–Hf isotope systems of zircons. 相似文献
42.
D. E. Saveliev V. N. Puchkov S. N. Sergeev I. I. Misabirov 《Doklady Earth Sciences》2017,476(1):1058-1061
Deformed orthopyroxene grains are studied in detail in mantle peridotite. It is shown that deformation of enstatite is accompanied by its decomposition with the formation of low-temperature phases (pargasite, Fe-rich olivine) and restite represented by depleted enstatite, forsterite, and small newly formed chrome spinellide grains. The role of plastic deformation in initiation of partial melting of peridotite and in the formation new chrome spinellide grains is discussed. 相似文献
43.
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45.
V. N. Chebrov D. V. Droznin S. Ya. Droznina N. Z. Zakharchenko Yu. A. Kugaenko D. V. Melnikov V. N. Mishatkin Ya. D. Murav’ev I. N. Nuzhdina A. V. Rybin S. L. Senyukov V. A. Sergeev S. S. Serovetnikov N. N. Titkov P. P. Firstov V. V. Yaschuk 《Seismic Instruments》2013,49(3):254-264
This work presents the project of the first stage of implementation of the integrated instrumental system of volcanic activity monitoring in Kamchatka and the Kuril Islands. The system of monitoring was designed for the purpose of ensuring public safety, aviation safety, and reducing economic losses caused by volcanic eruptions. The most active and dangerous volcanoes in Kamchatka (North and Avacha groups of volcanoes) and the Kuril Islands (volcanoes on the islands of Kunashir and Paramushir) are of first priority for monitoring. For this purpose, special observation points are planned to be installed on the volcanoes. The system of monitoring will include a complex of observations (broadband seismic station with a large dynamic range, tiltmeter, devices for gas, acoustic, and electromagnetic observations, and video camera). All the data will be passed to information processing centers in real time. New methods and algorithms of automatic and automated identification of the volcanic activity level and the probabilistic volcano hazard assessment have been developed. 相似文献
46.
A U-Pb (SHRIMP-II) geochronological study of rocks from the Sayzhenski, Snezhny and Nizhne-Burulzayski massifs, incorporated
into the Vitim alkali province (Sayzhenski Complex) has been made. The acquired data indicate that the rocks formed in the
interval of 520-486 Ma. The proximity of their age to accretionary-collision processes in the Central Asian fold belt, accompanied
by intràplate magmatism, has been noted. Two independent stages in the evolution of Vitim Province magmatism are suggested:
Early Paleozoic (520-485 Ma) and Late Paleozoic (350-290 Ma). 相似文献
47.
48.
N. N. Danchenko M. L. Kuleshova Z. P. Malashenko E. V. Petrova V. I. Sergeev 《Moscow University Geology Bulletin》2011,66(5):354-360
We study the filtering and sorption parameters of laboratory-produced composite materials, such as sand-gels, sand-gels with
an FeS activating additive, peat-gels, and commercial sorbents on the basis of cellulose coated with MnO2, which can be used for production of permeable geochemical barriers. The carry over and the efficiency of consumption of
the active component are estimated for materials with activating additives. It is shown that all the materials under study
can be used as fillers for a permeable geochemical barrier, but each of them has its own limitations. 相似文献
49.
A. M. Zubareva E. P. Pavlenko M. V. Andreev S. V. Antipin N. N. Samus’ A. V. Sergeev 《Astronomy Reports》2011,55(3):224-229
We have obtained data on various brightness states of the polar MT Dra over five years of observations, including the first
multicolor photometry for this close binary. We confirm the known orbital period, which has remained constant over 17 years,
which is unusual for cataclysmic binaries. Our observations in October 2006 demonstrated a transition of the polar to its
low brightness state within one day. 相似文献
50.
M. A. Yudovskaya V. V. Distler N. V. Rodionov A. V. Mokhov A. V. Antonov S. A. Sergeev 《Geology of Ore Deposits》2011,53(1):27-57
The formation conditions and age of the Sukhoi Log gold deposit are considered on the basis of new isotopic-geochemical data.
The U-Pb isotopic study of zircon and monazite from high-grade ore and host black slates at the Sukhoi Log deposit was carried
out with SIMS technique using a SHRIMP II instrument. Two generations of monazite are distinguished on the basis of optical
and scanning electron microscopy, cathodoluminescence, and micro X-ray spectroscopy. Monazite I is characterized by black
opaque porphyroblasts with microinclusions of minerals pertaining to metamorphic slates and structural attributes of pre-
and synkinematic formation. Monazite II occurs only within the ore zone as transparent crystals practically free of inclusions
and as rims around monazite I. The REE contents are widely variable in both generations. Porphyroblastic monazite I differs
in low U and Th (0.01–0.7 wt % ThO2) contents, whereas transparent monazite II contains up to 4 wt % ThO2. The average weighted U-Pb isotopic age of monazite
I is 650 ± 8.1 Ma (MSWD = 1.6; n = 9) and marks the time of metamorphism or catagenesis. The U-Pb age estimates of synore monazite II cover the interval of
486 ± 18 to 439 ± 17 Ma. Zircons of several populations from 0.5 to 2.6 Ga in age are contained in the ore. Most detrital
zircon grains have porous outer rims composed of zircon and less frequent xenotime with numerous inclusions of minerals derived
from slates. The peaks of 206Pb/238U ages in the most abundant zircon populations fall on 570 and 630 Ma and correspond to the age of newly formed metamorphic
mineral phases. The discordant isotopic ages indicate that the U-ThPb isotopic system of ancient detrital zircons was disturbed
470–440 Ma ago in agreement with isotopic age of monazite II and the Rb-Sr whole -rock isochron age of black slates (447 ±
6 Ma). The new data confirm the superimposed character of the gold-quartz-sulfide mineralization at the deposit. Black shales
of the Khomolkho Formation of the Bodaibo Synclinorium were affected by metamorphism over a long period; the peaks of metamorphism
and catagenesis are dated at 570 and 650–630 Ma. The high-temperature ore formation was probably related to a hidden granitic
pluton emplaced 450–440 Ma ago, that is, 200 Ma later than the events of greenschist metamorphism. Hercynian granitoid magmatism
(320–270 Ma) did not exert a substantial effect on the U-Th-Pb isotopic system in accessory minerals from the ore and could
not have been a major source of ore-forming fluids. 相似文献