内蒙古曹四夭钼矿花岗斑岩地质-地球化学特征及U-Pb同位素测年  

Geological-geochemical characteristics and U-Pb isotopic dating of Caosiyao Mo-granitic porphyry body in Xinghe County,Ulanqab Banner of Inner Mongolia

作　　者：李香资[1] 权知心[1] 付恒一[1] 安婧雯 杨位坤[1] 

机构地区：[1]河南省地质矿产勘查开发局第二地质勘查院,郑州450000

出　　处：《地质找矿论丛》2016年第3期325-333,共9页Contributions to Geology and Mineral Resources Research

摘　　要：内蒙古兴和县曹四夭超大型钼矿床的成矿岩体花岗斑岩为微型岩株,岩石为强酸性花岗岩,富含Rb,Li,Be,Nb,Zr和Mo,其中Mo的含量为克拉克值的20倍,岩石稀土总量较低,为轻稀土富集型,Eu严重亏损;U-Pb同位素测年结果显示,加权平均年龄为(133.5±7.4)Ma,时代为中生代白垩纪早期,花岗斑岩的形成年龄基本上代表了钼矿床的成矿年龄;岩体侵入的构造背景为燕山晚期的板内造山环境;花岗斑岩的成因为S型与I型的过渡类型,岩浆物质原始来源于上地幔以浅,岩浆沿深大断裂上侵形成花岗斑岩,揭示出上地壳基底物质与岩浆的同熔过程。The super-large Mo deposit-hosted granitic porphyry body is the stronger acidic granite occur- ring in mini stock with less porphyritic crystals. It is rich in Rb, Li,Be, Nb,Zr and Mo. Its Mo content is as 20 times as clarke value. P, REE is low （122. 388×10 6） belonging to LREE enrichment type with Eu depletion. The weighted U-Pb isotopic average age is 133.5 ± 7.4 Ma corresponding to Early Cretaceous epoch. Rock-forming age of the granitic porphyry represents the ore-forming age. The intrusion occurred under intra-plate orogenic background during Late Yanshanian Period. It is a transitional type of S and I- type granite. The material source of magma is derived above the upper mantle and intrudes up along huge fault as syntactic granitic porphyry.

关 键 词：曹四夭钼矿 成矿岩体 花岗斑岩 岩石地球化学 U—Pb同位素测年 成矿时代 内蒙古 

分 类 号：P613[天文地球—矿床学] P597[天文地球—地质学]