The role of carbonate-fluoride melt immiscibility in shallow REE deposit evolution

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62156489%3A43210%2F19%3A43915243" target="_blank" >RIV/62156489:43210/19:43915243 - isvavai.cz</a>

Alternative codes found

RIV/62156489:43410/19:43915243 RIV/00216305:26310/19:PU133154

Result on the web

<a href="https://doi.org/10.1016/j.gsf.2018.02.005" target="_blank" >https://doi.org/10.1016/j.gsf.2018.02.005</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.gsf.2018.02.005" target="_blank" >10.1016/j.gsf.2018.02.005</a>

Result language

angličtina

Original language name

The role of carbonate-fluoride melt immiscibility in shallow REE deposit evolution

Original language description

The Lugiin Gol nepheline syenite intrusion, Mongolia, hosts a range of carbonatite dikes mineralized in rare-earth elements (REE). Both carbonatites and nepheline syenite-fluorite-calcite veinlets are host to a previously unreported macroscale texture involving pseudo-graphic intergrowths of fluorite and calcite. The inclusions within calcite occur as either pure fluorite, with associated REE minerals within the surrounding calcite, or as mixed calcite-fluorite inclusions, with associated zirconosilicate minerals. Consideration of the nature of the texture, and the proportions of fluorite and calcite present (TILDE OPERATOR+D9129 and 71 mol%, respectively), indicates that these textures most likely formed either through the immiscible separation of carbonate and fluoride melts, or from cotectic crystallization of a carbonate-fluoride melt. Laser ablation ICP-MS analyses show the pure fluorite inclusions to be depleted in REE relative to the calcite. A model is proposed, in which a carbonate-fluoride melt phase enriched in Zr and the REE, separated from a phonolitic melt, and then either unmixed or underwent cotectic crystallization to generate an REE-rich carbonate melt and an REE-poor fluoride phase. The separation of the fluoride phase (either solid or melt) may have contributed to the enrichment of the carbonate melt in REE, and ultimately its saturation with REE minerals. Previous data have suggested that carbonate melts separated from silicate melts are relatively depleted in the REE, and thus melt immiscibility cannot result in the formation of REE-enriched carbonatites. The observations presented here provide a mechanism by which this could occur, as under either model the textures imply initial separation of a mixed carbonate-fluoride melt from a silicate magma. The separation of an REE-enriched carbonate-fluoride melt from phonolitic magma is a hitherto unrecognized mechanism for REE-enrichment in carbonatites, and may play an important role in the formation of shallow magmatic REE deposits.

Czech name

—

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

—

OECD FORD branch

10511 - Environmental sciences (social aspects to be 5.7)

Project

<a href="/en/project/LQ1601" target="_blank" >LQ1601: CEITEC 2020</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2019

Confidentiality

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

Name of the periodical

Geoscience Frontiers

ISSN

1674-9871

e-ISSN

—

Volume of the periodical

10

Issue of the periodical within the volume

2

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

11

Pages from-to

527-537

UT code for WoS article

000459141200016

EID of the result in the Scopus database

2-s2.0-85061291283