东昆仑祁漫塔格地区白干湖钨锡矿田白云母^(40)Ar/^(39)Ar定年及地质意义  

Muscovite ^(40)Ar/^(39)Ar dating of the Baiganhu W-Sn orefield,Qimantag,East Kunlun Mountains,and its geological implications

作　　者：郑震[1] 陈衍景[1] 邓小华[2] 岳素伟[3] 陈红瑾[1] 

机构地区：[1]北京大学造山带与地壳演化重点实验室,北京100861 [2]北京矿产地质研究所,北京100012 [3]华南理工大学广州学院,广东广州510802

出　　处：《中国地质》2016年第4期1341-1352,共12页Geology in China

基　　金：中国地质调查局项目"环塔里木前寒武纪铜镍-钨锡矿成矿规律及找矿方向"(1212011140056)资助~~

摘　　要：东昆仑祁漫塔格地区白干湖钨锡矿田是认识中国西北地区钨锡矿床成矿规律的重要窗口。作者对采自含矿石英脉的2个白云母样品进行40Ar/39Ar定年,获得其坪年龄分别为(422.7±4.5)Ma和(421.8±2.7)Ma。2个样品的等时线年龄与反等时线年龄也在误差范围内一致,分别为(424±15)Ma和(418±24)Ma,表明分析数据可信。获得的白云母40Ar/39Ar坪年龄指示成矿作用发生在晚志留世,与原特提斯洋闭合事件密切相关,闭合后的陆陆碰撞使富含成矿物质的变质沉积物重熔而形成花岗岩浆;花岗岩浆侵入并析出含矿热液,导致钨锡成矿。elt provides a key window toinsight into the W-Sn mineralization in Northwest China. In this paper, the authors present results from the 40Ar/39Ar dating of twomuscovite samples collected from the ore- bearing quartz veins in the Baiganhu W- Sn ore district, which yielded two 40Ar/39Arplateau ages of 422.7 ± 4.5 Ma and 421.8 ± 2.7 Ma, respectively. These two samples also yielded consistent （within errors）isochronal and inverse isochronal ages of 424 ± 15 Ma and 418 ± 24 Ma, respectively, suggesting that the analytical results arereliable. The new plateau ages show that the mineralization occurred in the Late Silurian, associated with the tectonic- thermalevents induced by the closure of Proto-Tethys. The post-subduction continental collision caused the formation of granitic magmassourced from re- melting of the metalliferous metamorphosed Proterozoic sediments. The W- Sn mineralization resulted by thehydrothermal fluids exsolved from the granitic magmas during their upward emplacement.

关 键 词：40Ar/39Ar定年 白云母 白干湖钨锡矿田 祁漫塔格 东昆仑造山带 

分 类 号：P597.3[天文地球—地球化学] P618.67[天文地球—地质学] P618.44