KŘÍBEK, Bohdan, Ilja KNÉSL, Petr DOBEŠ, František VESELOVSKÝ, Přemysl POŘÁDEK, Radek ŠKODA, Renata ČOPJAKOVÁ, Jaromír LEICHMANN and Filip KOŠEK. The Origin of Synchysite-(Ce) and Sources of Rare Earth Elements in the Rožná Uranium Deposit, Czech Republic. Minerals. MDPI, 2022, vol. 12, No 6, p. 1-26. ISSN 2075-163X. Available from: https://dx.doi.org/10.3390/min12060690.
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Basic information
Original name The Origin of Synchysite-(Ce) and Sources of Rare Earth Elements in the Rožná Uranium Deposit, Czech Republic
Authors KŘÍBEK, Bohdan (guarantor), Ilja KNÉSL, Petr DOBEŠ, František VESELOVSKÝ, Přemysl POŘÁDEK, Radek ŠKODA (203 Czech Republic, belonging to the institution), Renata ČOPJAKOVÁ (203 Czech Republic, belonging to the institution), Jaromír LEICHMANN (203 Czech Republic, belonging to the institution) and Filip KOŠEK.
Edition Minerals, MDPI, 2022, 2075-163X.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10505 Geology
Country of publisher Switzerland
Confidentiality degree is not subject to a state or trade secret
WWW URL
Impact factor Impact factor: 2.500
RIV identification code RIV/00216224:14310/22:00126295
Organization unit Faculty of Science
Doi http://dx.doi.org/10.3390/min12060690
UT WoS 000817325700001
Keywords in English synchysite; silica gel; uranium mineralization; the Rožná uranium deposit; rare earth elements
Tags rivok
Tags International impact, Reviewed
Changed by Changed by: Mgr. Marie Šípková, DiS., učo 437722. Changed: 21/7/2022 14:58.
Abstract
Synchysite was identified in the Rožná uranium deposit in a quartz–carbonate–sulfide vein, which is a part of the late (post-uranium and, post-Variscan) stage of the development of the hydrothermal system. The synchysite forms needles or lamellae, which are almost exclusively bound to the quartz filling of the veins. The structure of the quartz vein-filling, i.e., the preserved tubular syneresis crack pattern, Liesegang bands formed by hematite, chaotic grain size distribution of quartz grains, and ribbons of fibrous SiO2 grains, indicate that the synchysite crystallized in a silica gel. Its formation may be explained by the reaction of hydrothermal acid fluids rich in Fe2+ and rare earth elements (REEs) with alkaline Ca2+ HCO3− and F-rich fluids expelled from the gel during syneresis, or by its ageing. The subsequent recrystallization of the gel to form euhedral quartz grains was accompanied by the deformation of previously formed Liesegang rings, and the development of quartz rosettes. The study of fluid inclusions indicated that the silica gel originated at a very low temperature. The temperatures of the homogenization of two-phase inclusions in carbonate and quartz vein-filling varied between 38 and 74 °C, and the salinity ranged between 4 and 10 wt.% NaCl equiv. The δ13C carbonate values (from −4.65 to −5.21‰, PDB) indicate the deep-seated source of CO2, and δ18O values (from 14.76 to 18.22‰, SMOW) show that the source of the hydrothermal fluids was mainly surface water, with a possible admixture of fossil saline brines. The main sources of REEs are thought to have predominantly been uranium minerals (coffinitized uraninite and coffinite) that form a part of the breccia fragments embedded in the vein filling. The results illustrate the significant mobility of REEs in the late, low-temperature hydrothermal system, and they indicate the multiple remobilizations of REEs in the uranium deposits in general.
Links
EF16_026/0008459, research and development projectName: Dlouhodobý výzkum geochemických bariér pro ukládání jaderného odpadu
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