铜陵地区焦冲金硫矿床闪长玢岩锆石LA-ICP-MS U-Pb年龄及其地质意义  

LA-ICP-MS zircon U-Pb dating of dioritic porphyrite in Jiaochong Au-S deposit,Tongling area,and its geological significance

作　　者：阙朝阳[1,2] 吴淦国[1] 张达[1] 张志辉[1,3] 狄永军[1] 方红薇[1] 袁琴[1] 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]云南文山麻栗坡紫金钨业集团,云南文山663600 [3]中国地质调查局发展研究中心,北京100037

出　　处：《矿床地质》2013年第6期1221-1235,共15页Mineral Deposits

基　　金：安徽铜陵焦冲金(硫)多金属矿及蛤蟆岭金矿成因及成矿预测研究项目;全国危机矿山接替资源找矿项目(20089938);111计划(B07011)的联合资助

摘　　要：铜陵矿集区内广泛分布的铁铜硫金矿床被认为与中生代发生的大规模成岩作用密切相关，其中形成于140～150Ma之间的晚侏罗世高钾钙碱性岩体是主要的成矿岩体。文章选取铜陵焦冲金硫矿区与成矿相关的闪长玢岩开展了锆石LA-ICP—MSU—Pb同位素年代学研究，测得闪长玢岩LA-ICP—MS锆石U_Pb同位素年龄为（128．0±2。2）Ma，表明铜陵地区除晚侏罗世与大规模成矿作用相关的高钾钙碱性岩浆作用外，还存在一期早白垩世与金硫多金属成矿作用相关的岩浆活动。4个中一晚石炭世岩浆锆石一致年龄（309～328Ma）表明该区可能存在海西期的岩浆作用，但其规模、背景及与成矿的关系还需进一步研究。其他2组继承岩浆成因锆石核的一致性年龄（1870--1931Ma、600--808Ma）表明铜陵地区与扬子克拉通一样存在明显的古元古代及新元古代的岩浆作用。The Fe, Cu, S and Au deposits distributed all over the Tongling area are considered to be closely related to the large scale magmatic activities that occurred in Mesozoic, in which the late Jurrasic high K calc-alkalic intrusions formed in 140~150 Ma are the main ore-forming plutons. The authors selected the dioritic porphyrite related to the Jiaochong Au-S deposit to conduct LA-ICP-MS zircon U-Pb dating of the pluton, and yielded an age of （128.0±2.2） Ma. It is suggested that, in addition to the late Jurrasic high K calc-alkalic intrusions related to large scale mineralization, there also existed early Cretaceous magmatism in the Tongling area, which corresponded to Au-S mineralization. Four middle and late Carboniferous concordant ages of magmatic zircons （309~328 Ma） indicate that there possibly existed Hercynian magmatism, whose scale, setting and relationship with mineralization, however need further investigation. The other two groups of concordant ages for old inherited cores of magmatic origin （1870~1931 Ma and 600~808 Ma） suggest Paleo-and Neo-proterozoic magmatism in the Tongling area.

关 键 词：地球化学 IAICP-MSU-Pb年龄 锆石 闪长玢岩 焦冲金硫矿床 铜陵 

分 类 号：P618.51[天文地球—矿床学]