Development of REE mineralization in the giant Maoniuping deposit (Sichuan, China): insights from mineralogy, fluid inclusions, and trace-element geochemistry

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62156489%3A43410%2F19%3A43915016" target="_blank" >RIV/62156489:43410/19:43915016 - isvavai.cz</a>

Alternative codes found

RIV/00216305:26620/19:PU136072

Result on the web

<a href="https://doi.org/10.1007/s00126-018-0836-y" target="_blank" >https://doi.org/10.1007/s00126-018-0836-y</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00126-018-0836-y" target="_blank" >10.1007/s00126-018-0836-y</a>

Result language

angličtina

Original language name

Development of REE mineralization in the giant Maoniuping deposit (Sichuan, China): insights from mineralogy, fluid inclusions, and trace-element geochemistry

Original language description

Rare-earth deposits associated with intrusive carbonatite complexes are the world&apos;s most important source of these elements (REE). One of the largest deposits of this type is Maoniuping in the Mianning-Dechang metallogenic belt of eastern Tibet (Sichuan, China). In the currently mined central part of the deposit (Dagudao section), REE mineralization is hosted by a structurally and mineralogically complex Late Oligocene (26.4 +- 1.2 Ma, 40Ar/39Ar age of fluorphlogopite associated with bastnäsite) hydrothermal vein system developed in a coeval syenite intrusion. Low-grade stockworks of multiple veinlets and breccias in the lower part of the orebody grade upwards into progressively thicker veins (up to 12 m in width) that are typically zoned and comprise ferromagnesian micas (biotite to fluorphlogopite), sodium clinopyroxenes (aegirine to aegirine-augite), sodium amphiboles (magnesio-arfvedsonite to fluororichterite), K-feldspar, fluorite, barite, calcite, and bastnäsite. The latter four minerals are most common in the uppermost 80 m of the Dagudao section and represent the climax of hydrothermal activity. Systematic variations in the fluid inclusion data indicate a continuous hydrothermal evolution from about 230-400 oC (fluid inclusions in feldspar, clinopyroxene, and amphibole) to 140-240 oC (fluid inclusions in bastnäsite, fluorite, calcite). Hydrothermal REE transport was probably controlled by FMINUS SIGN , (SO4)2MINUS SIGN , ClMINUS SIGN , and (CO3)2MINUS SIGN as complexing ligands. We propose that at Dagudao, silicate magmas produced orthomagmatic fluids that explored and expanded a fissure system generated by strike-slip faulting. Initially, the fluids had appreciable capacity to transport REE and, consequently, no major mineralization developed. The earliest minerals to precipitate were alkali- and Fe-rich silicates containing low levels of F, which caused progressive enrichment of the fluid in Ca, Mg, F, Cl, REE, (SO4)2MINUS SIGN , and (CO3)2MINUS SIGN , leading to the crystallization of aegirine-augite, fluororichterite, fluorphlogopite, fluorite, barite, calcite, and bastnäsite gradually. Barite, fluorite, calcite, and bastnäsite are the most common minerals in typical ores, and bastnäsite generally postdates these gangue minerals. Thus, it is very probable that fluid cooling and formation of large amount of fluorite, barite, and calcite triggered bastnäsite precipitation in the waning stage of hydrothermal activity.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10504 - Mineralogy

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Mineralium Deposita

ISSN

0026-4598

e-ISSN

—

Volume of the periodical

54

Issue of the periodical within the volume

5

Country of publishing house

DE - GERMANY

Number of pages

18

Pages from-to

701-718

UT code for WoS article

000467483400006

EID of the result in the Scopus database

2-s2.0-85053221728