湘东北地区主要有色金属矿床成矿物质来源——来自硫、铅同位素的证据

Metallogenic material sources of important non-ferrous metal deposits in northern Northeast Hu’nan Province:Evidence from S and Pb isotopes

湘东北地区有色金属矿床成矿物质来源综合研究相对缺乏。以桃林铅锌矿、栗山铅锌矿、井冲钴铜多金属矿为研究对象,分析矿床主成矿期矿石硫化物单矿物的硫、铅同位素地质特征,结合七宝山铜多金属矿等研究现状,综合研究湘东北地区有色金属矿床的成矿物质来源规律。硫同位素特征表明,4个矿床的成矿物质整体为深部岩浆硫源,其中,七宝山矿床为较典型的岩浆硫源,桃林、栗山、井冲等矿床混入了少量地层硫源,且桃林矿床比栗山、井冲矿床混入地层硫源的比例更高。铅同位素特征表明,4个矿床的成矿物质来源以上地壳为主,但混入了少部分幔源物质,且七宝山、井冲的幔源物质混入比例更高。

The comprehensive research on the metallogenic material sources of the main non-ferrous metal deposits in northeastern Hu'nan Province has been very insufficient. Focusing on the Taolin lead- zinc deposit, Lishan lead- zinc deposit and Jingchong Cobalt- copper polymetallic deposit, the authors analyzed their S and Pb isotope geological characteristics of the single mineral of sulfide ore in their main metallogenic period, explored comprehensively the law of ore- forming material sources about the nonferrous metal ore deposits in northeastern Hu'nan Province, combined with research status of other deposits such as the Qibaoshan copper polymetallic deposit. The S isotope characteristics show that the metallogenic material of four deposits came from the deep magmatic sulfur source on the whole. The Qibaoshan ore deposit is a typical magmatic sulfur source,whereas the Taolin, Lishan and Jingchong deposits are all mixed with a small amount of formation sulfur. Moreover, the deposit with higher percentage of formation sulfur source is Taolin deposit. The Pb isotope characteristics show that the metallogenic material source of the four deposits is given priority to the upper crust, but is mixed with minor mantle source material on the whole. The higher mixing proportion of mantle source material came from Qibaoshan and Jingchong.