内蒙古黄岗梁铁锡矿床辉钼矿Re-Os年龄及其成因意义

Isotope age of Re-Os in molybdenite and genetic implication of Huanggangliang Fe-Sn deposit in Inner Mongolia

黄岗梁铁锡矿床是大兴安岭南段黄岗—甘珠尔庙成矿带的大型多金属矿床,有关其成因的研究直接影响着该区多金属矿床的区域找矿方向及对晚古生代和晚中生代2次造山作用地球动力学过程的成矿效应研究,但目前对矿床成因尚无统一认识。文章对两件辉钼矿样品Re-Os同位素进行了分析,得到了(141.2±4.3)Ma、(264.8±3.9)Ma的模式年龄,将其与该区及周边矿床中矿石和脉石矿物的年龄数据进行了比较,认为黄岗梁辉钼矿Re-Os同位素年龄数据比较可靠,应作为矿床的成矿年龄。认为黄岗梁铁锡矿床经历二叠纪喷流沉积和燕山期岩浆热液叠加的两期成矿作用。

Huanggangliang Fe-Sn deposit is a large scale polymetallic deposit located in the Huanggang - ganzhuermiao metallo- genic belt in Daxinganling range mountain area. The genesis study is important for the determination of the prospecting direction, and understanding of contribution of the orogenic movement which happened in the late Paleozoic and late Mesozoic periods. Two molybdenite samples were collected and analyzed to get Re-Os isotopic data, and the results showed that the model ages is （141.2±4.3）Ma and （264.8±3.9） M a respectively. When compared with the ages of ore minerals and gangue minerals that were formed around the deposit, it showed that the Huanggangliang Fe-Sn deposit was formed under the contribution of exhalative sedimentation that happened in the Permian period and the magmatic hydrothermal events of Yanshanian.