Genesis of the Weizigou Au Deposit, Heilongjiang Province, NE China: Constraints from LA-ICP-MS Trace Element Analysis of Magnetite, Pyrite and Pyrrhotite, Pyrite Re-Os Dating and S-Pb Isotopes

Minerals

Siyu Lu¹  Yujie Hao¹  Yu Gao¹ 

[1] College of Earth Sciences, Jilin University, Changchun 130061, China;

关键词: Weizigou Au deposit;    LA-ICP-MS;    pyrite Re-Os dating;    S-Pb isotope;    IOCG deposit;   

DOI  :  10.3390/min11121380

来源: DOAJ

【 摘 要 】

The Weizigou Au deposit in Heilongjiang Province, NE China, located in the southern Jiamusi Massif, shows similarities to IOCG deposits. To determine the mineralization age, sources of ore-forming materials and genetic type, pyrite Re-Os dating, S-Pb isotopic analysis, in situ sulfur analysis and LA-ICP-MS analysis of trace elements in magnetite, pyrite and pyrrhotite were conducted. Four pyrite samples yielded a Re-Os isochron age of 197 ± 11 Ma, implying the occurrence a metallogenic event in the Early Jurassic. The δ³⁴S values of sulfides display a relatively narrow range from 4.70‰ to 12.83‰ (mainly 9.90‰ to 12.83‰), which may be accounted for the extensively exposed granitic gneiss and meta-gabbro, with δ³⁴S values of 7.44‰ to 8.44‰ and 4.37‰ to 10.54‰, respectively. Sulfide lead isotopic compositions have ²⁰⁶Pb/²⁰⁴Pb = 18.605–20.136, ²⁰⁷Pb/²⁰⁴Pb = 15.637–15.710 and ²⁰⁸Pb/²⁰⁴Pb = 38.534–39.129, indicating that the lead was derived from a mixed source. Magnetite has the characteristics of a lower Ti content and higher Zn content, indicating that it should be of hydrothermal origin, which may be related to IOCG-type mineralization. Pyrite and pyrrhotite have a Co/Ni ratio greater than 1 and a lower As content, indicating that they are of magmatic hydrothermal origin. Integrating the above analysis results, we inferred that the Weizigou Au deposit experienced the IOCG-type mineralization in the Middle-Late Permian, associated with magmatic-hydrothermal mineralization in the Early Jurassic.

【 授权许可】

Unknown