投稿时间：2019-04-01
修订日期：2019-05-13
网络发布日期：2019-11-04
中文摘要:彭公庙岩体是南岭地区早古生代大花岗岩基的典型代表之一，在其周围发育有圳口、张家垄及杨梅坑等大-中型的钨矿床（点）。由于钨矿化主要产出于彭公庙岩体的内部及其周缘地层中，这些矿床过去一直被认为形成于早古生代，与彭公庙岩体有着紧密的成因联系。然而，这些矿床与大花岗岩基的时间及成因关系尚未准确厘定。文章在已有研究的基础上，对圳口钨矿进行了高精度白云母Ar-Ar测年，获得坪年龄为（148.0±0.7）Ma（MSDW=3.1），对应的等时线年龄为（148.1±0.8）Ma（MSDW=2.6），反等时线年龄为（148.1±0.8）Ma（MSDW=2.6），表明圳口钨矿床形成于晚侏罗世，明显晚于早古生代彭公庙大花岗岩基的侵位时间，是南岭地区中-晚侏罗世大规模钨锡成矿事件的一部分。通过总结研究发现，区域上早古生代花岗岩基周缘的钨锡矿床均形成于晚侏罗世，该结论不仅表明研究区深部晚侏罗世岩浆活动强烈，而且指示区内不同矿床之间在成因上密切相关。整个区域上的矿床类型和空间分布显示出不同的围岩性质制约了不同的矿化过程，从而形成不同的矿床类型。含矿热液沿着裂隙通道向上运移，当围岩为花岗岩时，形成了石英脉-云英岩型矿床，而当围岩为碎屑岩时，则形成石英脉型矿床。这些不同类型矿床可以构成一套矿床组合模型，互为找矿指示。
Abstract:The Penggongmiao granite batholith is one of the typical representatives of the Early Palaeozoic large granite batholiths in the Nanling region. Recently, large to medium-sized tungsten deposits, such as Zhenkou, Zhangjialong and Yangmeikeng, were discovered around the Penggongmiao granite batholith. Because of the main orebodies present in the interior of the Penggongmiao granite batholith and the surrounding strata, these deposits are considered that formation of Early Palaeozoic and relate to Penggongmiao granite. However, the timing and genetic relationship between these deposits and large granite batholith is unclear. Based on the existed research, the high-precision muscovite Ar-Ar dating of the Zhenkou tungsten deposit was carried out, and yielded a well-defined 40Ar/39Ar plateau age of (148.0±0.7) Ma(MSDW=3.1), with an isochron age of (148.1±0.8) Ma(MSDW=2.6)and an inverse isochron age of (148.1±0.8) Ma(MSDW=2.6), indicating that the Zhenkou tungsten deposit formed in the Late Jurassic. This age is consistent with the Zhenkou tungsten deposit was formed in the Late Jurassic and obviously later than the emplacement time of the Early Palaeozoic Penggongmiao granite batholith, which is part of the large-scale tungsten-tin metallogenic event of the Late Jurassic in the Nanling region. The comparative study on the area shows that the tungsten and tin deposits around the periphery of the Early Palaeozoic granite in the region are formed in the Late Jurassic, indicating not only the intense Late Jurassic granite magmatic activity of the deep, but also the close genetic relationship between different deposits in the area. The deposit types and spatial distribution in the whole region show that different physicochemical properties of wall rock may control the mineralization processes and ore deposit types. The ore-bearing hydrothermal fluid was brought by granite emplacement, and migrated along the presence of fault channe lways. When the surrounding rock is granite, quartz vein-greisen type deposit is formed, and when the surrounding rock is Sinian clastic rock, quartz vein type deposit may be formed. Therefore, different types of deposits can forming metallogenic model, which are prospecting indicators for each other.
keywords:geochemistry Ar-Ar dating Early Palaeozoic Penggongmiao granite Zhenkou tungsten southern Hunan Province
文章编号：
中图分类号：P618.67
文献标志码：
基金项目:本文得到国家自然科学基金项目（编号：41672095、41773041）、优秀青年科学基金项目（编号：41822304）和中国地质科学院基本科研业务费专项经费（编号：YYWF201711）联合资助
引用文本：
严宸,赵海杰,赵盼捞,袁顺达.2019.湘南圳口石英脉型黑钨矿床白云母Ar-Ar同位素测年及其对区域找矿勘查的指示[J].矿床地质,38(5):1147~1158YAN Chen,ZHAO HaiJie,ZHAO PanLao,YUAN ShunDa.2019.Muscovite Ar-Ar isotopic dating of Zhenkou quartz vein type wolframite deposit in southern Hunan Province and its significance for regional exploration[J].Mineral Deposits38(5):1147~1158
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