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1.
E.V. Lazareva S.M. Zhmodik A.V. Prokopiev N.S. Karmanov A.I. Sergeenko 《Russian Geology and Geophysics》2018,59(10):1330-1347
Nodular monazite occurs in metamorphic rocks worldwide and has zonal REE patterns. This paper focuses on the composition of nodular monazite hosted by Permian black shales of the Kular Ridge in the Kular-Nera terrane. This monazite variety (called kularite in the Russian literature) reaches commercial amounts in placers of the area. The contents of Ce, Nd, and La in the analyzed monazite nodules show correlations at Ce/Nd = 14.39La + 0.0919 (in apfu) and Ce/Nd = 0.2318La + 0.1135 (in wt.%) and vary regularly from core to rim. All monazite compositions fall on this trend, but specific grains may plot in its different parts. Thermodynamic calculations indicate that monazite forms via an intermediate precursor (LnPO4·2H2O). The Ce:La:Nd changes in different grains record Eh-pH variations during nucleation and a gradual temperature increase during subsequent growth. The Ce:La:Nd ratio changes partly in grain rims as a result of oxidative dissolution. Judging by the tectonic setting, REE came to the Kular-Nera rocks from the weathered Tomtor Nb-REE deposit, being transported by the Paleo-Khatanga River with monazite nanoparticles bound to the surface of clay minerals. 相似文献
2.
Dobretsov N. L. Zhmodik S. M. Lazareva E. V. Bryanskaya A. V. Ponomarchuk V. A. Saryg-ool B. Yu. Kirichenko I. S. Tolstov A. V. Karmanov N. S. 《Doklady Earth Sciences》2021,496(2):135-138
Doklady Earth Sciences - Data indicating the important role of microorganisms in the redistribution of REEs in the weathering crust and the decisive role in the concentration of REEs during the... 相似文献
3.
G. S. Ripp A. G. Doroshkevich M. V. Badmatsyrenov N. S. Karmanov 《Geochemistry International》2007,45(6):538-545
The composition and nature of high-Cr minerals in lithic clasts from the carbonatites of the Veseloe occurrence, northern Transbaikalia, were considered. In order to determine their source, the Cr-bearing phases were compared with chromite, magnetite, and rutile from ultrabasic rocks, mantle xenoliths, and eclogites. It was suggested that the xenoclasts studied were formed at great depths, whereas the carbonatites were directly derived from the mantle rather than formed by the crustal differentiation of a silicate-carbonate melt. 相似文献
4.
V. B. Savelyeva E. P. Bazarova V. V. Sharygin N. S. Karmanov 《Geology of Ore Deposits》2015,57(8):645-656
Fine-grained segregations up to 5 mm in size composed of graphic intergrowths of zircon, quartz, calcite and containing up to 0.8 wt % SrO have been found in albite–riebeckite and dolomite–biotite metasomatic rocks formed after alaskite granite. They contain magnetite, titanomagnetite (25.4 wt % TiO2), cerite-(Ce,Nd), rutile (up to 1.2 wt % Nb2O5), as well as rare micrograins of monazite-(Ce), bastnaesite-(Ce), and barite (up to 5.7 wt % SrO). The fine-grained structure of mineral aggregates suggests a metacolloidal nature. It is assumed that the zircon–quartz–calcite assemblage was formed due to exchange decomposition reaction between the salt phase of hydrothermal solution with predominant Na2CO3, elevated Zr and, to a lesser extent, Fe, Ti, LREE, Nb contents and dissolved calcium and silica compounds of a Na2SiO3 type. 相似文献
5.
Atkin E. V. Bulatov V.L. Vasiliev O. A. Voronin A. G. Gorbunov N. V. Grebenyuk V. M. Dorokhov V. A. Karmanov D. E. Kovalev I.M. Kudryashov I. A. Kurganov A.A. Merkin M. M. Panov A.D. Podorozhny D. M. Polkov D. A. Porokhovoi S. Yu. Sveshnikova L. G. Tkachev L.G. Tkachenko A. V. Turundaevskiy A. N. Filippov S. B. Shumikhin V. V. 《Astronomy Reports》2019,63(1):66-78
Astronomy Reports - Some results of studies of cosmic rays obtained during the NUCLEON space experiment in 2015–2017 are presented. This experiment was intended for direct measurements of the... 相似文献
6.
The composition of accessory minerals from granites of the second phase, quartz-muscovite (+fluorite), and quartz-muscovite-topaz
greisens from the Primorsky rapakivi granite complex, West Baikal region, were studied using backscattered scanning electron
microscopy. Ilmenite from granites contains inclusions of cassiterite, titanocolumbite, fergusonite-(Y), polycrase-(Y), and
betafite. Allanite-(Ce), bastnaesite-(Ce), xenotime-(Y), Y- and Zr-thorite, zircon, and cyrtolite have been identified in
granites. Greisens contain cassiterite, ferrocolumbite (Ta/Nb = 0.02−0.06), pyrochlore-group minerals, ilmenorutile, rutile,
wolframite, polycrase-(Y), monazite-(Ce), fluocerite-(Ce), bastnaesite-(Ce), cerphosphorhuttonite, thorite, and other minerals.
The ferrocolumbite + ilmenorutile assemblage is typical of quartz-muscovite greisen, whereas the rutile + ilmenorutile + wolframite
+ W-columbite assemblage is contained in the quartzmuscovite-topaz greisen as a result of an increase in Eh and decrease in
pH and potassium activity of solution in the back zone. The compositions of Th- and REE-bearing minerals indicate the important
role of phosphate and fluorine complexes in the transport of these elements. 相似文献
7.
The fault-line REE-bearing carbonatites of the Arshan deposit were described for the first time twenty years ago (Bulnaev, 1985, 2000). The elevated REE contents were explained by the occurrence of bastnaesite and allanite. Fine parisite grains after bastnaesite phenocrysts were noted as well (Ripp et al., 2000). In the present study, parisite and allanite replacing bastnaesite were examined with SEM/EDS. The investigation has shown the metasomatic origin of both minerals and their essentially cerium composition. Sm, Eu, Gd, Dy, and Yb in amounts of n(0.001–0.1)% were detected with spectrochemical analysis. 相似文献
8.
Drits A. V. Kravchishina M. D. Sukhanova I. N. Belyaev N. A. Karmanov V. A. Flint M. V. 《Oceanology》2021,61(6):984-993
Oceanology - Sedimentation rates in the northern Kara Sea between September 2019 and July 2020 were calculated from integrated monthly values for sedimentary matter, organic carbon, nitrogen, total... 相似文献
9.
Doklady Earth Sciences - In the taxitic gabbro-dolerites of the upper contact zone of the Norilsk-1 intrusion, five boron minerals were found: kotoite Mg3(BO3)2, suanite Mg2B2O5, warwickite... 相似文献
10.
G. A. Palyanova Yu. L. Mikhlin N. S. Karmanov K. A. Kokh Yu. V. Seryotkin 《Doklady Earth Sciences》2017,474(2):636-640
The forms of Au and Ag occurrence in the crystallization products of melts in the Fe–S–Ag–Au system depending on the proportions of Fe/S and Ag/Au have been studied at (Fe + S)/(Ag + Au) = 0.1. It is shown that the S-rich systems with S/Fe = 2 contain Au–Ag sulfides and Au–Ag alloys. The systems depleted in S with S/Fe = 1 contain only Au–Ag alloys. The results of XPS provide evidence for the sulfide and metallic components of Au and Ag among the crystallization products of melts in the system studied at S/Fe = 2 and a metallic component with S/Fe = 1. According to the data of electron microprobe analysis, the content of “invisible” forms of noble metals in pyrite and pyrrhotite is < 0.024 wt % for Au and <0.030 wt % for Ag; the contents of “invisible” Au and Ag in troilites are 0.040 ± 0.013 wt % Au and 0.079 ± 0.016 wt % Ag. 相似文献