四川冕宁尤黑木铁铜多金属矿床成矿时代和成因探讨:地球化学和独居石U-Pb定年证据  

Metallogenic epoch and genesis of the Youheimu iron-copper polymetallic deposit in Mianning,Sichuan:evidence from U-Pb dating of monazite and geochemistry of rocks and ores

作　　者：王玉山 周勇[1] 吕小军 王飞 金飞 陈泽军 万平益 WANG Yushan;ZHOU Yong;LYU Xiaojun;WANG Fei;JIN Fei;CHEN Zejun;WAN Pingyi(No.605 Party,Sichuan Bureau of Metallurgical Geology&Exploration,Meishan 620860,China)

机构地区：[1]四川省冶金地质勘查局六〇五大队,四川眉山620860

出　　处：《桂林理工大学学报》2023年第4期547-558,共12页Journal of Guilin University of Technology

基　　金：四川省地质矿产勘查开发局项目(SCDKZCKJXM-2022039)。

摘　　要：扬子地块西缘的康滇铁铜成矿带是我国重要的富铜和富铁矿石产地之一,但其多个矿床的成矿时代和矿床成因还存在争议。位于四川冕宁的尤黑木铁铜多金属矿床多个矿体均成一定规模,对该矿床铁铜矿体围岩与矿石进行了地球化学分析,并对矿石进行LA-ICP-MS独居石U-Pb定年。尤黑木铁铜矿体围岩(黑云石英片岩)原岩为火山沉积形成的以黏土矿物为主的泥质岩,其中有古老沉积物组分的加入。该铁铜矿体LA-ICP-MS独居石U-Pb年龄有两组:一组为812.8±4.6 Ma,代表围岩康定群冷竹关组形成年龄;另一组为698.5±5.0 Ma,代表铁铜矿体的成矿年龄。综合分析认为,研究区东部酸性岩浆带来的热液流体顺着围岩层间破碎带运移,与围岩发生交代作用及矽卡岩化,形成矿体,因此该矿床为岩浆热液-矽卡岩成因。The Kangdian iron-copper metallogenic belt on the western margin of the Yangtze landmass is one of the important copper rich and iron rich ore producing areas in China.However,the metallogenic epoch and gen-esis of many of its deposits are still controversial.Many orebodies of Youheimu iron-copper polymetallic ore de-posit located in Mianning,Sichuan,have reached a certain scale.There are few previous studies and reports on this,and its genesis and mineralization age are still unclear.In this paper,the wall rock and ore of the iron-copper orebody of the deposit are analyzed by geochemistry,and the ore is dated with LA-ICP-MS monazite U-Pb.The protolith of wall rock(biotite quartz schist)of the Heheimu iron-copper orebody is argillaceous rock mainly composed of clay minerals formed by volcanic deposition,with the addition of ancient sediment compo-nents.The LA-ICP-MS monazite U-Pb dating in Youheimu iron-copper orebody has two groups:one group is 812.8±4.6 Ma,representing the formation age of Lengzhuguan formation of Kangding Group;the other group is 698.5±5.0 Ma,representing the mineralization age of iron-copper orebody.The hydrothermal fluid brought by acid magma in the east of the study area flows in to the interlayer fracture zone of the wall rock,undergoes meta-somatism and skarnization with the surrounding rock,and forms iron-copper orebody.The genesis of the deposit is magmatic hydrothermal skarn.

关 键 词：铁铜多金属矿床 独居石U-Pb定年 地球化学 成矿时代 矿床成因 尤黑木 

分 类 号：P611.3[天文地球—矿床学]