内蒙古查干德尔斯钼矿成矿期花岗岩地球化学特征及成岩背景  

Metallogenic Granite Geochemical Characteristics and Diagenetic Background of the Chagandeersi Molybdenum Deposit,Inner Mongolia

作　　者：李光耀 肖荣阁[3] 李志丹 王佳营 LI Guang-yao;XIAO Rong-ge;LI Zhi-dan;WANG Jia-ying(Tianjin Center, China Geological Survey, Tianjin 300170, China;Key Laboratory of Uranium Geology, China Geological Survey, Tianjin 300170, China;China Univercity of Geosciences (Beijing), Beijing 100083, China)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国地质调查局铀矿地质重点实验室,天津300170 [3]中国地质大学(北京),北京100083

出　　处：《科学技术与工程》2021年第28期12010-12019,共10页Science Technology and Engineering

基　　金：中国地质调查项目(12120113057300,DD20190119,DD20211191);国家自然科学基金(41502082)。

摘　　要：查干德尔斯钼矿床位于中蒙边界西段宝音图隆起,是近年勘查发现的一处大型隐伏矿床。辉钼矿化常见于晚二叠世花岗质岩体中,多呈浸染状、网脉状分布,具斑岩型矿床特征。通过对成矿期查干德尔斯岩体——似斑状黑云母二长花岗岩开展系统的元素地球化学分析研究,进而探讨其成岩背景。结果表明:查干德尔斯岩体具有高硅、高碱、过铝质和高钾钙碱性特征。通过微量元素地球化学研究,认为查干德尔斯岩体的原岩受到早期陆缘弧俯冲作用,进而部分熔融,岩浆上侵到浅部地壳后与下元古界宝音图群发生混染,并且伴随成矿物质的富集沉淀。Nb-Y和Rb-(Y+Nb)构造环境判别图解显示,德尔斯岩体形成演化的构造背景为晚古生代末期的后碰撞环境。Chagandeersi molybdenum deposit is located in Baoyintu uplift in the western part of the China-Mongolian border.It is a large-scale concealed deposit discovered in recent years.Molybdenite mineralization is common in the Late Permian granites,which is disseminated,stockwork,and has the characteristics of porphyry deposits.Based on the systematic element geochemical analysis of the porphyry biotite monzogranite-the Chagandeersi pluton in the metallogenic period,its diagenetic background was discussed.The results show that the Chagandeersi pluton was characterized by high silicon,high alkali,peraluminous and high potassium calc alkaline.By studying trace element geochemistry,it was considered that the protolith of Chagandeersi pluton was subducted by the early continental margin arc,and then partially melted.After the magma intruded into the shallow crust,it was mixed with the Baoyintu group of Lower Proterozoic,accompanied by the enrichment and precipitation of ore-forming materials.The discrimination diagrams of Nb-Y and Rb-(Y+Nb)tectonic environments show that the tectonic setting of the Chagandeersi pluton is a post collisional environment at the end of Late Paleozoic.

关 键 词：斑岩型钼矿床 高钾钙碱性 后碰撞环境 查干德尔斯 

分 类 号：P597.3[天文地球—地球化学] P611.1[天文地球—地质学]