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Fluid Evolution, H-O Isotope and Re-Os Age of Molybdenite from the Baiyinhan Tungsten Deposit in the Eastern Central Asian Orogenic Belt, NE China, and Its Geological Significance
- Source :
- Minerals, Volume 10, Issue 8, Minerals, Vol 10, Iss 664, p 664 (2020)
- Publication Year :
- 2020
- Publisher :
- Multidisciplinary Digital Publishing Institute, 2020.
-
Abstract
- The quartz-vein-type Baiyinhan tungsten deposit is located at the eastern part of the Central Asian Orogenic Belt, NE China. Analyses of fluid inclusions, H-O isotope of quartz and Re-Os isotope of molybdenite were carried out. Three stages of mineralization were identified: The early quartz + wolframite + bismuth stage, the middle quartz + molybdenite stage and the late calcite + fluorite stage. Quartz veins formed in the three stages were selected for the fluid inclusion analysis. The petrographic observation and fluid inclusion microthermometry results revealed three types of fluid inclusions: CO2-H2O (C-type), liquid-rich (L-type) and vapor-rich (V-type). The homogenization temperatures of C-type, V-type and L-type inclusions were 233&ndash<br />374 &deg<br />C, 210&ndash<br />312 &deg<br />C, and 196&ndash<br />311 &deg<br />C, respectively. The salinity of the three types of inclusions was identical, varying in the range of 5&ndash<br />12 wt%. The H-O isotope analyses results showed that quartz had &delta<br />18OH2O and &delta<br />DSMOW compositions of &minus<br />2.6&permil<br />to 4.3&permil<br />and &minus<br />97&permil<br />to &minus<br />82&permil<br />respectively, indicating that the ore-forming fluids were mainly derived from magmatic water with a minor contribution of meteoric water. The addition of meteoric water reduces the temperature and salinity of the ore-forming fluids, which leads to a decrease of the solubility of tungsten and molybdenum in the fluids and eventually the precipitation of minerals. Re-Os isotopic analysis of five molybdenite samples yielded an isochron age of 139.6 &plusmn<br />7.6 Ma (2&sigma<br />) with an initial 187Os of &minus<br />0.05 &plusmn<br />0.57 (MSWD = 3.5). Rhenium concentrations of the molybdenite samples were between 3.1 ug/g and 8.5 ug/g. The results suggest that the metals of the Baiyinhan deposit have a crust origin, and the mineralization is one episode of the Early Cretaceous tungsten mineralization epoch which occurred at the eastern part of the Central Asian Orogenic Belt.
- Subjects :
- inorganic chemicals
Wolframite
lcsh:QE351-399.2
010504 meteorology & atmospheric sciences
H-O isotope
Geochemistry
engineering.material
010502 geochemistry & geophysics
01 natural sciences
complex mixtures
Re-Os dating
Petrography
Magmatic water
Fluid inclusions
Quartz
0105 earth and related environmental sciences
Isochron
lcsh:Mineralogy
Chemistry
technology, industry, and agriculture
Geology
respiratory system
eastern Central Asian Orogenic Belt
Geotechnical Engineering and Engineering Geology
fluid inclusions
Molybdenite
engineering
Meteoric water
quartz-vein tungsten deposit
Subjects
Details
- Language :
- English
- ISSN :
- 2075163X
- Database :
- OpenAIRE
- Journal :
- Minerals
- Accession number :
- edsair.doi.dedup.....4d48e12aa99f11ad661773564f1d0194
- Full Text :
- https://doi.org/10.3390/min10080664