scholarly journals Gem-Quality Zircon Megacrysts from Placer Deposits in the Central Highlands, Vietnam—Potential Source and Links to Cenozoic Alkali Basalts

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 89 ◽  
Author(s):  
Vuong Bui Thi Sinh ◽  
Yasuhito Osanai ◽  
Christoph Lenz ◽  
Nobuhiko Nakano ◽  
Tatsuro Adachi ◽  
...  
Keyword(s):  
Rare Earth ◽  
Alkali Basalt ◽  
Earth Element ◽  
Alkali Basalts ◽  
Potential Source ◽  
Icp Ms ◽  
Close Proximity ◽  
Placer Deposits ◽  
Central Highlands ◽  
Lithospheric Mantle Source

Gem-quality zircon megacrysts occur in placer deposits in the Central Highlands, Vietnam, and have euhedral to anhedral crystal shapes with dimensions of ~3 cm in length. These zircons have primary inclusions of calcite, olivine, and corundum. Secondary quartz, baddeleyite, hematite, and CO2 fluid inclusions were found in close proximity to cracks and tubular channels. LA-ICP-MS U-Pb ages of analyzed zircon samples yielded two age populations of ca. 1.0 Ma and ca. 6.5 Ma, that were consistent with the ages of alkali basalt eruptions in the Central Highlands at Buon Ma Thuot (5.80–1.67 Ma), Pleiku (4.30–0.80 Ma), and Xuan Loc (0.83–0.44 Ma). The zircon geochemical signatures and primary inclusions suggested a genesis from carbonatite-dominant melts as a result of partial melting of a metasomatized lithospheric mantle source, but not from the host alkali basalt. Chondrite-normalized rare earth element patterns showed a pronounced positive Ce, but negligible Eu anomalies. Detailed hyperspectral Dy3+ photoluminescence images of zircon megacrysts revealed resorption and re-growth processes.

scholarly journals The sequential REE (Rare Earth Elements) extraction of weathered crusts of granitoids from Sibolga, Indonesia

2021 ◽  
Vol 882 (1) ◽  
pp. 012020
Author(s):  
I Setiawan
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Sequential Extraction ◽  
Ion Adsorption ◽  
Potential Source ◽  
Ms Analysis ◽  
Icp Ms ◽  
The Future ◽  
Placer Deposits ◽  
Mineralogical Compositions

Abstract Indonesia needs a proven technology for REE extraction to build a national REE industry. Monazite that has been recovered from placer deposits at Bangka-Belitung areas is the most potential REE source. In the future, ion adsorption type will be another potential source of REE deposits. This paper describes the sequential REE extraction of the weathered crusts of granitoids from Sibolga using sequential extraction ICP-MS analysis is applied to determine bulk samples mineralogical compositions and REE content. The total REE (∑REE) content of weathered crusts of granitoids from Sibuluhan Sihaporas A ranges from 265 to 479 ppm, while the amount of ∑REE leached by sequential extraction range from 151 to 263 ppm, and the percentage of adsorbed ∑REE ranges from 55 to 74%. In comparison, Sibuluhan Sihaporas B ranges from 302 to 634 ppm, 82 to 198 ppm, and 28 to 44%, respectively. ∑REE content of weathered granitoids crusts from Sarudik ranges from 135 to 219 ppm, while that SREE leached by sequential extraction range from 21 to 82 ppm, and percentage of adsorbed ∑REE range from 11 to 50 %, while that Sibolga Julu ranges from 191 to 304 ppm, 111 to 138 ppm, and 27 to 44%.

scholarly journals A User‐Friendly Workbook to Facilitate Rapid and Accurate Rare Earth Element Analyses by ICP‐MS for Multispiked Samples

2020 ◽  
Vol 21 (9) ◽  
Author(s):  
Y. Wu ◽  
L. D. Pena ◽  
S. L. Goldstein ◽  
C. Basak ◽  
L. L. Bolge ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Icp Ms ◽  
User Friendly

Rare earth element determination in heavy crude oil by USN-ICP-MS after digestion using a microwave-assisted single reaction chamber

2016 ◽  
Vol 31 (6) ◽  
pp. 1185-1191 ◽  
Author(s):  
Gabriel T. Druzian ◽  
Leticia S. F. Pereira ◽  
Paola A. Mello ◽  
Marcia F. Mesko ◽  
Fabio A. Duarte ◽  
...  
Keyword(s):  
Rare Earth ◽  
Crude Oil ◽  
Rare Earth Element ◽  
Earth Element ◽  
Reaction Chamber ◽  
Heavy Crude Oil ◽  
Microwave Assisted ◽  
Icp Ms ◽  
Heavy Crude ◽  
Single Reaction

In this work a method for rare earth element (REE) determination by inductively coupled plasma mass spectrometry (ICP-MS) was proposed after heavy crude oil digestion by microwave-assisted wet digestion (MAWD) using a single reaction chamber (SRC) system.

scholarly journals Mineralogical and geochemical characterisation of the Kipawa syenite complex, Quebec: implications for rare-earth element deposits

2022 ◽  
Author(s):  
S Matte ◽  
M Constantin ◽  
R Stevenson
Keyword(s):  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Crustal Contamination ◽  
Hydrothermal Activity ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Gneissic Granite ◽  
Icp Ms ◽  
Regional Tectonic

The Kipawa rare-earth element (REE) deposit is located in the Parautochton zone of the Grenville Province 55 km south of the boundary with the Superior Province. The deposit is part of the Kipawa syenite complex of peralkaline syenites, gneisses, and amphibolites that are intercalated with calc-silicate rocks and marbles overlain by a peralkaline gneissic granite. The REE deposit is principally composed of eudialyte, mosandrite and britholite, and less abundant minerals such as xenotime, monazite or euxenite. The Kipawa Complex outcrops as a series of thin, folded sheet imbricates located between regional metasediments, suggesting a regional tectonic control. Several hypotheses for the origin of the complex have been suggested: crustal contamination of mantle-derived magmas, crustal melting, fluid alteration, metamorphism, and hydrothermal activity. Our objective is to characterize the mineralogical, geochemical, and isotopic composition of the Kipawa complex in order to improve our understanding of the formation and the post-formation processes, and the age of the complex. The complex has been deformed and metamorphosed with evidence of melting-recrystallization textures among REE and Zr rich magmatic and post magmatic minerals. Major and trace element geochemistry obtained by ICP-MS suggest that syenites, granites and monzonite of the complex have within-plate A2 type anorogenic signatures, and our analyses indicate a strong crustal signature based on TIMS whole rock Nd isotopes. We have analyzed zircon grains by SEM, EPMA, ICP-MS and MC-ICP-MS coupled with laser ablation (Lu-Hf). Initial isotopic results also support a strong crustal signature. Taken together, these results suggest that alkaline magmas of the Kipawa complex/deposit could have formed by partial melting of the mantle followed by strong crustal contamination or by melting of metasomatized continental crust. These processes and origins strongly differ compare to most alkaline complexes in the world. Additional TIMS and LA-MC-ICP-MS analyses are planned to investigate whether all lithologies share the same strong crustal signature.

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