In-situ composition and geologic significance of multi-stage quartz in Xicha Gold-Silver Deposit,Jilin Province
Xicha Gold-Silver Deposit is classified as a mesothermal vein type deposit formed in the Early Creta-ceous,primarily containing gold with associated silver.The mineralization process went through both a hydrothermal mineralization period and a supergene mineralization period,with the hydrothermal mineralization period divided into 3 stages,each characterized by the development of hydrothermal quartz.Using LA-ICP-MS in-situ micro-zone analysis techniques,micro element composition analysis of quartz at different mineralization stages was conducted.The results indicate that the second stage is the main mineralization stage with the strongest mineralization,serving as the primary gold mineralization phase.Gold-bearing minerals are predominantly sulfides,but during the second stage,the content of Sb and Bi significantly increases,and gold and silver show a positive correlation with other metallic elements such as copper,lead and zinc,suggesting that the gold-bearing minerals in the main mineralization stage may also include telluride and bismuthide,or be encapsulated in quartz in the form of fine particles.The quartz Ti geothermome-ter constructed based on the titanium content in hydrothermal quartz indicates a gradual decrease in mineralization temperature during the hydrothermal mineralization period.The systematic changes in Al,Ti,and Li content in quartz suggest a gradual increase in fluid pH from initial acidity towards neutral to weak alkalinity.