The factors affecting mineralization potential of arc magma:Insights from silicate melt inclusions and zircon composition of igneous lava at Eastern Taiwan Island  

作　　者：Jianping LI Shitao ZHANG Gaobin CHU Huayong CHEN 

机构地区：[1]Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China [2]Department of Earth and Planetary Sciences,McGill University,Montreal H3A0E8,Canada [3]State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China [4]Guangzhou Tuoyan Analytical Technology Co.Ltd,Guangzhou 510600,China [5]Guangdong Provincial Key Laboratory of Mineral Physics and Materials,Guangzhou 510640,China [6]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Earth Sciences》2025年第3期768-780,共13页中国科学(地球科学英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant No. 41921003);the National Key R&D Program of China (Grant No. 2022YFC2903301);the National Natural Science Foundation of China (Grant No. 42003031);financial support from the China Scholarship Council program (CSC) during the stay at McGill University。

摘　　要：Subduction-related Cu-(Au) deposits which represent giant geochemical anomalies of metals and S in the upper crust are commonly associated with arc magmas. However, the fundamental differences between barren and fertile magma producing these deposits still remain highly controversial. In this study, we report the chemical compositions of zircon and silicate melt inclusions(SMIs) from barren arc lavas at eastern Taiwan Island aiming to increase our knowledge on the factors that affect the mineralization potential of arc magma systems. The zircon U-Pb dating shows the magmatism occurred at ~0.7 Ma and the andesitic lava formed at ~900–950℃ with a reduced magmatic environment. The plagioclase-hosted SMIs show an andesitic melt composition and variable Cu content features. The calculated H_(2)O content of parental melt is ~3–4 wt.%. The evidence presented above suggests that oxidation state(f O_(2)) and H_(2)O content are probably the key controls of Cu-(Au) fertility of arc magmas. We interpret that a reduced and relatively dry magma may be a potential hinderance to cause the absence of porphyry Cu deposits at the eastern Taiwan Island.

关 键 词：Silicate melt inclusions ZIRCON Redox state Arc magma Cu-(Au)mineralization potential 

分 类 号：P59[天文地球—地球化学]