Geochemistry and Sr-Nd-Pb Isotopes of the Granites from the Hashitu Mo Deposit of Inner Mongolia, China： Constraints on Their Origin and Tectonic Setting

作     者：DING Chengwu DAI Pan BAGAS Leon NIE Fengjun JIANG Sihong WEI Junhao DING Chengzhen ZUO Pengfei ZHANG Ke 

作者机构：MLR Key Laboratory of Metallogeny and Mineral AssessmentInstitute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China Faculty of Earth ResourcesChina University of Geosciences(Wuhan)Wuhan 430074HubeiChina School of Earth and EnvironmentThe University of Western Australia35 Stirling HighwayCrawleyWestern Australia 6009 Geophysical Research Institute of BGP Inc.China National Petroleum CorporationZhuozhou 072751 HebeiChina School of the Earth Sciences and ResourcesChina University of GeosciencesBeijing 100083China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2016年第90卷第1期

页      面：106-120页

核心收录：

学科分类：070902[理学-地球化学] 081803[工学-地质工程] 0709[理学-地质学] 07[理学] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：part of the ongoing project "Superimposed tectonic activities and large-scale oreforming processes of the Hinggan-Mongolia Orogenic Belt" financially supported by the State Basic Research Program of China(2013CB429805) 

主　　题：granite Sr-Nd-Pb isotopes Hashitu Mo deposit Great Hinggan Range 

摘      要：The Hashitu molybdenum deposit is located in the southern part of the Great Hinggan Range, NE China. Molybdenum mineralization is hosted by and genetically associated with monzogranite and porphyritic syenogranite. Sr-Nd-Pb isotopes of the intrusions show that the porphyritic syenogranite has initial ^87Sr/^86Sr ratios of 0.70418-0.70952, ENd（t） values of 1.3 to 2.1 （t=143 Ma）, ^206Pb/^204Pb ratios of 19.191-19.573, ^207Tpb/^204pb ratios of 15.551-15.572, and ^208Pb/^204Pb ratios of 38.826-39.143. The monzogranite has initial 87Sr/86Sr ratios of 0.70293-0.71305, εNd（t） values of 1.1 to 2.0 （t=-147 Ma）, ^206Pb/^204pb ratios of 19.507-20.075, ^207Pb/^204Pb ratios of 15.564-15.596, and ^208Pb/^204Pb ratios of 39.012-39.599. The calculated Nd model ages （TDM） for monzogranite and porphyritic syenogranite range from 866 to 1121 Ma and 795 to 1020 Ma, respectively. The granitic rocks in the Hashitu area have the same isotope range as granites in the southern parts of the Great Hinggan Range. The isotope composition indicates that these granites are derived from the partial melting of a juvenile lower crust originating from a depleted mantle with minor contamination by ancient continental crust. The integrating our results with published data and the Late Mesozoic regional tectonic setting of the region suggest that the granites in the Hashitu area formed in an intra-continent extensional setting, and they are related to the thinning of the thickened lithosphere and upwelling of the asthenosphere.