Trace elements in magmatic and hydrothermal quartz:Implications on the genesis of the Xingluokeng Tungsten Deposit,South China  

作　　者：Qing-Qing Zhang You-Wei Chen Jian-Feng Gao 

机构地区：[1]State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Acta Geochimica》2024年第3期441-458,共18页地球化学学报（英文）

基　　金：This study is financially supported by the National Science Fund for Distinguished Young Scholars(No.42025301);Guizhou Provincial 2020 Science and Technology Subsidies(No.GZ2020SIG).

摘　　要：The Xingluokeng deposit is the largest gran-ite-related tungsten deposit within the Wuyi metallogenic belt in South China.The Xingluokeng intrusion primarily consists of porphyritic biotite granite,biotite granite,andfine-grained granite.The deposit is represented by veinlet-disseminated mineralization with K-feldspathization and biotitization,alongside quartz-vein mineralization with gre-isenization and sericitization.This study investigates in-situ analyses of quartz compositions from both the intrusion and hydrothermal veinlets and veins.Trace element correlations indicate that trivalent Al^(3+)and Fe^(3+)replace Si^(4+)within the quartz lattice,with monovalent cations(such as Li^(+),Na^(+),and K^(+))primarily serving as charge compensators.Low Ge/Al ratios(<0.013)of quartz from granites suggest a mag-matic origin.The low Al/Ti and Ge/Ti ratios,accompanied by high Ti contents in quartz,suggest that the porphyritic biotite granite and biotite granite are characterized by rela-tively low levels of differentiation and high crystallization temperatures.In contrast,thefine-grained granite exhibits a higher degree of fractionation,lower crystallization tem-peratures,and a closer association with tungsten miner-alization.Ti contents in quartz from quartz veins indicate Qz-Ⅰformed at temperatures above 400°C,while Qz-Ⅱto Qz-Ⅴformed at temperatures below 350°C.Variations in different generations of quartz,as indicated by Al content and(Al+Fe)/(Li+Na+K)ratio,suggest that Qz-Ⅰprecipi-tated from a less acidicfluid with a stable pH,whereas Qz-Ⅱto Qz-Ⅴoriginated from a more acidicfluid with notable pH variations.Consequently,alkaline alteration and acidic alteration supplied the essential Ca and Fe for the precipita-tion of scheelite and wolframite,respectively,highlighting a critical mechanism in tungsten mineralization at the Xin-gluokeng deposit.

关 键 词：QUARTZ Xingluokeng Tungsten deposit Trace elements South China 

分 类 号：P618.67[天文地球—矿床学]