@article{oai:air.repo.nii.ac.jp:00005950,
 author = {Bounliyong, Patthana and Sumino, Hirochika and Arribas, Antonio},
 issue = {10},
 journal = {MINERALS},
 month = {},
 note = {K-Ar dating and He-3/He-4 and Ar-40/Ar-36 analyses were conducted on samples of hydrothermal quartz from the Thongkai-Ok Au deposit in the Vangtat orogenic Au belt of southern Laos to study the presence of excess argon in hydrothermal quartz and to better understand the origin of the ore-forming fluids. The K-Ar age of two hydrothermal quartz separates yielded apparent dates of 1040 and 1385 Ma. These ages are significantly older than the estimated age of Vangtat Au mineralization (similar to 200 Ma) and other regional geologic events, indicating the presence of an extraordinary amount of excess argon in the hydrothermal quartz crystals. In vacuo crushing analyses of the Thongkai-Ok hydrothermal vein quartz delivered He-3/He-4 approximate to 0.2-0.3 R/Ra and Ar-40/Ar-36 approximate to 455-725, suggesting the ore-forming fluid is mainly derived from a crustal component with a minor contribution of mantle and meteoric fluids.},
 title = {Large Amount of Excess Argon in Hydrothermal Quartz from the Vangtat Orogenic Gold Belt, Southern Laos: New In-Sight from K-Ar and Noble Gas Isotope Analyses},
 volume = {12},
 year = {2022}
}