Helium and argon isotope trace in ore-forming fluid of Sawuer gold belt in Xinjiang,China

• Published in: Chinese science bulletin Vol. 49; no. 13; pp. 1408 - 1414
• Main Author: SHEN, Ping
• Format: Journal Article
• Language: English
• Published: Beijing Springer Nature B.V 2004; Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
• Subjects: Argon; Belts; Deposits; Fluid inclusions; Gold; Helium; Island arcs; Isotopes; Meteoric water; Mineralization; Oceanic crust; Pyrite; Sediments; Subduction (geology); 同位素跟踪; 幔源流; 火山晚期热水金矿床; 矿石形成流体; He-Ar isotope; meteoric water; Sawuer gold belt; mantle-derived fluid; volcanogenic late-stage hydrothermal gold deposit; ore-forming fluid
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1360/03wd0620

The helium and argon isotope compositions of fluid inclusions hosted in pyrite have been measured from Kuoerzhenkuola and Buerkesidai gold deposits in Sawuer gold belt, northern Xinjiang. The results show that fluidinclusion ^3He/^4He ratios are 0.64 Ra-4.25 Ra and 1.16 Ra-9.48 Ra, ^40Ar/^36Ar ratios are 282-359 and 312-525 for Kuoerzhenkuola and Buerkesidai gold deposits respectively.The ore-forming fluids of two deposits possessed the same source and derived mainly from mantle beneath the island arc (including oceanic crust and oceanic sediments by subduction of oceanic plate). They were diluted by incorporating meteoric water to form a mixture of mantle- and partial meteoric water-derived fluid. The ore-forming fluids of twodeposits are of the same evolutionary histories. From the early to the late mineralization stages, the ratios of meteoric water/mantle- derived fluid in ore-forming fluid increasedgrad ually. Based on these results and detailed geological and geochemical studies on the two deposits, it is proposed that the geneses of the two gold deposits are the same, being volcanogenic late-stage hydrothermal gold deposits occurring in the same volcanic apparatus.