现代地质2017，Vol.31Issue(6)：1095-1113,19.
内蒙古巴彦都兰铜矿地质特征及矿床成因——岩石地球化学、锆石U-Pb年代学及Hf同位素证据
U-Pb Zircon, Geochemical and Hf Isotopic Constraints on Origin of the Bayandulan Copper Deposit, Inner Mongolia, China
摘要
Abstract
The Bayandulan high-mesothermal vein-type copper deposit is a newly discovered deposit in the Erenhot-East Ujimqin Banner metallogenic belt.In this paper,the authors present the new results of zircon laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb dating,rock geochemistry and insitu Hf isotopic analyses of biotite monzogranite from the deposit.These data provide insights into the timing as well as the mineralization of the Bayandulan deposit.The LA-ICP-MS U-Pb dating yields the crystallization ages of (300.2 ± 2.2) Ma and (300.0 ± 2.0) Ma for biotite monzogranite.The rock geochemistry of the granite is rich in Si,high potassium calc-alkali,weakly peraluminous,together with highly enriched the light rare earth element (LREE),Rb,K and other large-ion lithophile element (LILE),depleted Sr,Nb,Ta and other high field-strength element (HFSE).The granite has high positive εHf(t) values of 6.1-10.7 and two-stage model ages (TDM2) of 632-924 Ma,which reveals that granites are mainly derived from the partial melting of young accreted lower crust converted from the subduction of oceanic crust.Based on these analytical results,we inferred that the tectonic setting of the Bayandulan deposit has been entered into the post-orogenic stage and gradually turned to widely extension setting,since the Hegenshan back-arc basin closed between Late Carboniferous and Early Permian.During this period,the lithosphere delamination effect after collision and the upwelling of the mantle material under tension mechanism made young accreted lower crust reactivation,then acidic magma mixed with mantle source material,the emplacement of the magma brought sufficient metal elements and hydrothermal fluids,which in the end formed the Bayandulan copper deposit.关键词
巴彦都兰铜矿/锆石U-Pb年代学/Hf同位素/后碰撞构造环境/二连浩特—东乌旗多金属成矿带/内蒙古Key words
Bayandulan copper deposit/zircon U-Pb geochronology/Hf isotope/post-collisional setting/Erenhot-East Ujimqin Banner metallogenic belt/Inner Mongolia分类
天文与地球科学引用本文复制引用
余超,柳振江,宓奎峰,王常波,张杰,王建平,刘家军,张梅..内蒙古巴彦都兰铜矿地质特征及矿床成因——岩石地球化学、锆石U-Pb年代学及Hf同位素证据[J].现代地质,2017,31(6):1095-1113,19.基金项目
内蒙古自治区地质勘查基金项目(2014-01-YS01) （2014-01-YS01）
中国地质调查局地质矿产资源调查评价专项(1212011220923) （1212011220923）
中国地质调查局新兴产业资源战略调查评价专项工程项目(1212011220673). （1212011220673）
