J 2023

Gadolinium-dominant monazite and xenotime: Selective hydrothermal enrichment of middle REE during low-temperature alteration of uraninite, brannerite, and fluorapatite (the Zimná Voda REE-U-Au quartz vein, Western Carpathians, Slovakia)

ONDREJKA, Martin, Pavel UHER, Štefan FERENC, Stanislava MILOVSKÁ, Tomáš MIKUŠ et. al.

Základní údaje

Originální název

Gadolinium-dominant monazite and xenotime: Selective hydrothermal enrichment of middle REE during low-temperature alteration of uraninite, brannerite, and fluorapatite (the Zimná Voda REE-U-Au quartz vein, Western Carpathians, Slovakia)

Autoři

ONDREJKA, Martin (garant), Pavel UHER, Štefan FERENC, Stanislava MILOVSKÁ, Tomáš MIKUŠ, Alexandra MOLNÁROVÁ, Radek ŠKODA (203 Česká republika, domácí), Richard KOPÁČIK a Peter BAČÍK

Vydání

American Mineralogist, Mineralogical Society of America, 2023, 0003-004X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 3.100 v roce 2022

Kód RIV

RIV/00216224:14310/23:00132873

Organizační jednotka

Přírodovědecká fakulta

DOI

UT WoS

000974358600013

Klíčová slova anglicky

Monazite; xenotime; hingganite; Gd-enrichment; REE fractionation; MREE enrichment; tetrad effect; Western Carpathians

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 9. 1. 2024 08:53, Mgr. Marie Šípková, DiS.

Anotace

V originále

A hydrothermal quartz vein with REE-U-Au mineralization in the Zimna Voda (Gemeric Unit, Western Carpathians, Slovakia) is associated with contact metamorphism between Permian granites and host phyllites and metaquartzites. It contains unique REE minerals of the monazite and xenotime groups. Monazite-(Ce), monazite-(Nd), monazite-(Sm), and Gd-dominant monazite ["monazite-(Gd)"], along with xenotime-(Y) to Gd-dominant xenotime ["xenotime-(Gd)"] and Gd-rich hingganite-(Y) show heterogeneous compositions and reflect a strong fractionation trend toward the enrichment of MREE (Sm to Dy), particularly Gd. Here, the gadolinium abundance reported in "monazite-(Gd)" (=23.4 wt% Gd203) and Gd-rich xenotime-(Y) to "xenotime-(Gd)" (<28.7 wt% Gd203) and accompanied by Gd-rich hingganite-(Y) (<15.8 wt% Gd203), is among the highest Gd concentrations ever reported in natural minerals. The Gd-richest compositions show the following formulas: (Gd0.31Sm0.24 Nd0.15Ce0.10La0 .05Dy0.03Y0.03...)0.98P04 ["monazite-(Gd)"], (Gd0.36Y0.32Dy0.13Sm0.08Tb0.05...)0.98 (P0.96As0.04)1.0004 ["xenotime-(Gd)"] and (Y0.71Gd0.43Dy0.23Sm0.22Tb0.06Er0.04Nd0.06...Ca0.06)1.9 6 (o0.87Fe2+0.13)1.00(Be1.82B0.18)2.00(Si1.90As0.10)2.0008(OH1.7000.30)2.00 [hingganite-(Y)]. The MREE-rich monazites, xenotimes, and hingganite-(Y) precipitated in response to the alteration of primary uraninite, brannerite, and fluorapatite by low-temperature hydrothermal fluids of heterogeneous compositions on a microscale. These are responsible for the strong enrichment of individual MREE, especially Gd in the secondary minerals. This is accompanied by the advancing development of the W-type tetrad effect on REE through monazite species. The substantial incorporation of Gd into both REE-selective monazite and xenotime structures that are accompanied by LREE vs. HREE segregation indicates the possibility of differently sized REE3+ miscibility in REEPO4 solid solutions, as well as the stabilization of the Gd-rich orthophosphate structure by substitution of the remaining A-site cations with smaller HREE+Y in the xenotime-type, and/ or larger LREE in the monazite-type structure.