Petrogenesis and Mineralization of Xitian Tin-Tungsten Polymetallic Deposit: Constraints from Mineral Chemistry of Biotite from Xitian A-Type Granite, Eastern Hunan Province
Zhou Yun
Liang Xinquan
Cai Yongfeng
Fu Wei
Abstract：Chemical composition of biotite is always used to reveal source characteristics,tectonic environment,late hydrothermal process and enrichment of ore-forming elements.The Xitian tin-tungsten polymetallic deposit is one of the most important polygenetic compound deposits in South China.This study presents detailed mineral composition of biotites and feldspars from Xitian granite,which is closely related to the formation of the deposit.Electron microprobe analyzer (EMPA) analysis indicates that the biotites have low MgO (0.12％-1.35％) and high FeOT (15.47％-23.24％) contents with Fe/(Fe+Mg) ratios of 0.87 to 0.99,resembling to those of siderophyllite.These features indicate that their host rocks were mainly derived from partial melting of crustal materials.Estimation results of crystallization temperatures and oxygen fugacity suggest that the Xitian granite has high crystallization temperatures and low oxygen fugacities.Therefore,it is proposed that hydrothermal fluids during the late stage of magmatic evolution are favour of Sn enrichment.These hydrothermal fluids could be an important source of ore-forming fluids.High iron indexes and crystallization temperatures and low oxygen fugacities in the ore-forming system are favorable for mineralization of Xitian tin-tungsten deposit.
Keywords：biotitemineral compositionpetrogenesis and mineralizationgraniteXitian tin-tungsten polymetallic depositgeochemistry
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 1647-1657 )