Origin of heavy rare earth element enrichment in carbonatites
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F41601670%3A_____%2F23%3AN0000010" target="_blank" >RIV/41601670:_____/23:N0000010 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1016/j.gca.2023.08.025" target="_blank" >http://dx.doi.org/10.1016/j.gca.2023.08.025</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.gca.2023.08.025" target="_blank" >10.1016/j.gca.2023.08.025</a>
Alternative languages
Result language
angličtina
Original language name
Origin of heavy rare earth element enrichment in carbonatites
Original language description
Heavy rare earth elements (HREE) are currently in high demand for use in high technology, renewable energy and low-carbon transport, but they are the least abundant in nature. Carbonatites are the primary source of REE; however, they are dominated by light REE (LREE). It remains unknown whether carbonatites have the potential to form economic HREE mineralization. Here we report a xenotime-bearing carbonatite in the Bachu REE deposit, northwestern Tarim Large Igneous Province (TLIP), China, and infer the origin of HREE in carbonatites. The rocks evolved from dolomite to calcite carbonatites, and their HREE content correspondingly increased. Both types of rocks have similar monazite U-Pb ages (ca. 300 Ma), and are older than the major eruption of flood basalt of the TLIP, and associated alkaline complexes. They contain higher εNd(t) (2.4–4.1) and lower initial Sr isotopic ratios [(87Sr/86Sr)i = 0.7036–0.7041] than the basalts but similar values to those of younger alkaline rocks. The carbonatites are inferred to be directly derived from low-degree melting of lithospheric mantle sources induced by a deep-seated mantle plume. Calcite carbonatites contain characteristic xenotime, which is associated with burbankite, sulfates, and minor quartz. The rock-forming calcite shows high HREE abundance and flat REE patterns (La/Ybcn = 0.3–2.1). Apatite and LREE minerals in calcite carbonatites also have a higher HREE content (e.g., Y2O3 up to 2 wt%) than those in dolomite rocks. This finding indicates that the early dolomite carbonatite underwent strong fractionation of dolomite and LREE minerals, resulting in HREE and alkali enrichment in the evolved calcite rocks. High amounts of alkalis further enhance the solubility of REE, particularly HREE, in the residual melts. Silica assimilation from the country rocks facilitates the HREE mineralization by sequestering alkalis. Therefore, HREE enrichment in carbonatites may require substantial fractional crystallization of initial melts as well as alkali conservation during ascent.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
<a href="/en/project/GX19-29124X" target="_blank" >GX19-29124X: EVOLUTION AND POST-EMPLACEMENT HISTORY OF CARBONATITES: IMPLICATIONS FOR THE MOBILITY AND CONCENTRATION OF CRITICAL METALS</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2023
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Geochemica et Cosmochimica Acta
ISSN
0016-7037
e-ISSN
1872-9533
Volume of the periodical
362
Issue of the periodical within the volume
December 2023
Country of publishing house
US - UNITED STATES
Number of pages
12
Pages from-to
115-126
UT code for WoS article
001110835400001
EID of the result in the Scopus database
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