湘东锡田合江口锡钨多金属矿床地质特征及辉钼矿Re-Os同位素年龄  

Geological characteristics and molybdenite Re-Os isotopic age of Hejiangkou tungsten and tin polymetallic deposit,East Hunan,China

作　　者：邓湘伟[1,2] 刘继顺[1,2] 戴雪灵 

机构地区：[1]中南大学有色金属成矿预测教育部重点实验室,长沙410083 [2]中南大学地球科学与信息物理学院,长沙410083 [3]湖南省有色地质勘查局,长沙410016

出　　处：《中国有色金属学报》2015年第10期2883-2897,共15页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划前期研究专项(2007CB416608);湖南省创新基金资助项目(CX2010B105);中南大学优秀博士生基金资助项目(2010ybfz050)

摘　　要：对合江口矿的矿床地质特征,特别是岩相学和矿相学特征进行系统研究,并对该矿床中的辉钼矿进行Re-Os同位素测年,获得印支期(225±3.6 Ma)成岩成矿作用的地质和年代学证据;结合以往的成岩成矿时代资料,认为锡田地区存在多期成矿事件,并讨论成矿动力学演化特征。结果表明:合江口矿床的第Ⅰ期成矿事件发生在印支期,成矿物质来源为壳幔混合源,发生于挤压大地构造背景中,矿化较弱;第Ⅱ期为燕山早期,在拉张的构造背景下,幔源物质大规模参与成矿,是本区的主成矿期;第Ⅲ期为燕山晚期,是与花岗斑岩脉侵入相关的斑岩-矽卡岩型矿体的成矿期,该期形成的矿体为锡田矿田内新发现类型,也是下一步的找矿方向之一。The geology and mineralogy of the Hejiangkou deposit and conducted Re-Os isotopic dating on molybdenite from the Hejiangkou deposit were systematically studied. The dating results provided new evidence for the mineralization that occurred during the Indosinian （225±3.6 Ma）. By combining the rock-forming ages and mineralization ages obtained by both previous researches, the Xitian area experienced multi-periods mineralizations. Moreover, the metallogenetic tectonic settings of different mineralizations were also discussed. The results show that period I is the Indosinian mineralization period that involves mixing between both crust-derived and mantle-derived ore-forming materials. The period of mineralization took place under the compressional tectonic regime and featured by the weak mineralization. Period Ⅱ is the early Yanshanian mineralization that represents the main mineralization period of the area and is related to a large influx of mantle-derived materials under an extensional regime. Period Ⅲ is the late Yanshanian porphyry-skarn type mineralization that is related to the emplacement of granite-porphyry veins and is a recently discovered type in the Xitian orefield. The porphyry-skarn type mineralization also becomes the target of the futureore-prospecting.

关 键 词：锡钨矿床 多期成矿作用 RE-OS同位素 合江口 锡田 钦杭带 

分 类 号：P597.3[天文地球—地球化学]