【作者】 李光耀；

【导师】 肖荣阁；

【作者基本信息】 中国地质大学(北京) ， 矿物学、岩石学、矿床学， 2012， 硕士

【摘要】 查干德尔斯钼矿床是近年来在内蒙古西部中蒙边境地区发现的一个具大型规模的隐伏矿床，辉钼矿化呈浸染状、团块状、细脉状分布在中细粒二长花岗岩体中，具斑岩型矿床的特点。矿床成矿期花岗岩为似斑状黑云母二长花岗岩，刘翼飞等（2012）对花岗岩样品进行锆石SHRIMP U-Pb年龄测定结果分别为253.3±2.8Ma和253.8±3.7Ma，显示成矿期花岗岩形成于253-254Ma，为晚二叠世。蔡明海（2011）对矿区辉钼矿Re-Os测年研究（~243Ma）对比显示，矿床的成岩成矿时间差约为10Ma，这与成矿期花岗岩的结构构造特征相符，也可与国内外较多的斑岩型矿床类比，反映出查干德尔斯钼矿床是成矿岩体——黑云母二长花岗岩经历长时间岩浆-热液演化的产物。元素地球化学研究显示，成矿期花岗岩具有高硅、高碱、过铝质和高钾钙碱性特征。其源岩受到早期陆缘弧俯冲作用改造及地壳物质混染，后来发生部分熔融。花岗岩微量元素也继承了早期陆缘弧成因的一些特征。岩浆形成以后，在深部岩浆房内发生了以斜长石和钾长石为主导的分离结晶作用，并在上侵到地壳浅部区域后受下元古界宝音图群的混染，赋矿花岗岩体形成的构造背景为古生代末期向中生代转换的后碰撞环境。更多还原

【Abstract】 Chagandeersi molybdenum deposit, located in central-west Inner Mongolia,China, is a newly discovered large scale deposit. It is a porphyry molybdenumdeposit characterized by disseminated, spot and veinlet mineralizations hosted inmedium-fine grained monzonitic granite. Geochronological and elemental data arepresented for the ore-forming granites. The data(by Liu Yifei,2012) show that theore-forming granite was emplaced and crystallized in the Late Permian(253-254Ma).Compared with the molybdenite Re-Os dating(243Ma) form literature(CaiMinghai,2011), it indicate that the Chagandeersi molybdenum deposit was formedabout10Ma after the ore-forming granite.The major elements data show these granites are high K calc-alkaline series,metaluminous-peraluminous and characteristic of high silicon, high alkali.Combined with the trace elements features, it indicates that the ore-forming magmasis most plausibly originated by partial melting of previous subduction modifiedsource, and has inherited some features of subduction related magma. Theore-forming magma has undergone plagioclase and potash feldspar dominatedcrystal fractionation process before transported to the ore forming structure and werecontaminated by the baoyintu gneiss. The forming of these granites andChagandeersi molybdenum deposit were favored by the post-collision regime as thechemical features show.更多还原