Chronology and Fluid Inclusions of the Guoluolongwa Gold Deposit in Qinghai Province

作者：Yanna Xiao · 发表于：Acta Geological Sinica · 年份：2014 · 被引用次数：15 · 研究领域：Geochemistry and Geochronology of Asian Mineral Deposits、Geochemistry and Geologic Mapping、Geoscience and Mining Technology

The Guoluolongwa gold deposit is located in the eastern section of East Kunlun orogenic belt and the south of the central Kunlun fault.40 Ar/39 Ar dating has yielded ages of 201.8~229.3Ma,centering at 202. 2~204.6 Ma and with an average date of 202.7±1.5 Ma.The homogenization temperature of fluid inclusions ranges from 126~280℃while the salinity ranges from 6.8%~17.5%NaCl.The characteristics of ore-forming fluids show that mineralization was closely related to magmatic hydrothermal fluid, indicating that the deposit is a medium temperature magmatic hydrothermal deposit.The fluid inclusions are dominantly H2O and CO2,with minor CH4and H2.The cation ions in fluid inclusions are mainly Na+ and K+,and the main anion ions are SO2-4and Cl-.All fluid inclusion are generally characterized by Cl-SO2-4and Na+K+,indicating which the ore-forming fluid belong to CO2-Na+(K+,Ca+)-Cl-(SO2-4, F-)-H2O type fluids.Hydrothermal activities at the late stage contain distinct separation of H2O and CO2.And this resulted in the transformation and enrichment. Measurement of fluid inclusions compositions suggests that the ore-forming fluid is alkaline,S-rich fluid with Na+K+,and this is consistent with that of the ore-forming fluids in the whole East Kunlun metallogenic belt.