Инд. авторы:	Lazareva E.V., Zhmodik S.M., Prokopiev A.V., Karnanov N.S., Sergeenko A.I.
Заглавие:	Nodular monazite from placers in the Kular Ridge (Arctic Siberia, Russia): composition and age
Библ. ссылка:	Lazareva E.V., Zhmodik S.M., Prokopiev A.V., Karnanov N.S., Sergeenko A.I. Nodular monazite from placers in the Kular Ridge (Arctic Siberia, Russia): composition and age // Russian Geology and Geophysics. - 2018. - Vol.59. - Iss. 10. - P.1330-1347. - ISSN 1068-7971. - EISSN 1878-030X.
Внешние системы:	DOI: 10.1016/j.rgg.2018.09.010; SCOPUS: 2-s2.0-85054927299; WoS: 000447674000010;
Реферат:	eng: 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 (LnPO(4)center dot 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. (C) 2018, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.
Ключевые слова:	ZIRCON; XENOTIME; STREAM SEDIMENTS; BLACK-SHALE; AUTHIGENIC MONAZITE; DEPOSIT; EH-PH DIAGRAMS; RARE-EARTH-ELEMENTS; Kular Ridge; rare-earth elements; nodular monazite (kularite); U-PB; MINERALS;
Издано:	2018
Физ. характеристика:	с.1330-1347