云南个旧老厂细脉带型锡矿白云母^40Ar-^39Ar年龄及其地质意义  

^(40)Ar-^(39)Ar dating of muscovite from Laochang veinlet-like Sn deposit in Gejiu tin polymetallic ore district and its geological significance

作　　者：杨宗喜[1] 毛景文[1,2] 陈懋弘[2] 童祥 武俊德 程彦博[1] 赵海杰[2] 

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]中国地质科学院矿产资源研究所,北京100037 [3]云南锡业集团,云南个旧661400

出　　处：《矿床地质》2009年第3期336-344,共9页Mineral Deposits

基　　金：国家重点基础研究发展计划973"项目(编号:2007CB411407和2007CB411405);中国地质调查局项目(编号:1212010634001)资助成果

摘　　要：细脉带型锡矿是云南个旧矿田老厂矿区的主要矿床类型之一。文章利用40Ar-39Ar同位素测年方法对老厂细脉带型锡矿床白云母-电气石-石英脉中的白云母进行了年龄测试。结果显示,该白云母的40Ar-39Ar同位素坪年龄为(82.7±0.7)Ma,表明其形成时代为晚白垩世。进一步结合区域资料,指出包括个旧锡多金属矿床在内的右江褶皱带内与岩浆作用有关的矿床具有相同的成矿地质背景,为华南晚中生代岩石圈大规模伸展的产物。The veinlet-like Sn ore is one of the main ore types in the Laochang deposit of Gejiu orefield. ^40Ar-^39Ar dating of muscovite separated from the quartz-tourmaline-muscovite vein in Laochang ore district gives a ^40Ar-^39Ar plateau age of （82.7 ± 0.7） Ma, suggesting that the ore-forming process in the Laochang veinlet-like Sn deposit took place in late Cretaceous. Based on geochronological data of the Dulong Sn-Zn deposit, the Bainiuchang Ag deposit, the Dachang tin polymetaUic orefield and the Wangshe Cu-W deposit and an analysis of the tectonic evolution in the South China Block, the authors hold that these deposits resulted from the large-scale extension in South China under the same geodynamic condition in late Mesozoic.

关 键 词：地球化学 40Ar-39Ar同位素年龄 白云母 细脉带型锡矿 个旧老厂 

分 类 号：P618.44[天文地球—矿床学] P597.3[天文地球—地质学]