大兴安岭南段锡多金属矿床成矿岩体全岩地球化学、锆石U-Pb年龄、Hf同位素特征及其地质意义--以边家大院、毛登、宝盖沟矿床为例  

Whole-rock Geochemistry,Zircon U-Pb Ages,and Hf Isotopic Characteristics of Ore-related Intrusions of the Tin Polymetallic Deposits in the Southern Great Xing'an Range and Their Geological Significance:Case Studies of the Bianjiadayuan,Maodeng,and Baogaigou Deposit

作　　者：张雪旎 张宇飞[2] 彭蓉 杨颖 曾庆栋[4] ZHANG Xueni;ZHANG Yufei;PENG Rong;YANG Ying;ZENG Qingdong(School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083;Shandong Provincial Lunan Geology and Exploration Institute(Shandong Provincial Bureau of Geology and Mineral Resources No.2 Geological Brigade),Jining,Shandong 272100;MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037;Key Laboratory of Mineral Resources/Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]山东省鲁南地质工程勘察院(山东省地质矿产勘查开发局第二地质大队),山东济宁272100 [3]中国地质科学院矿产资源研究所自然资源部成矿作用与资源评价重点实验室,北京100037 [4]中国科学院地质与地球物理研究所/矿产资源研究重点实验室,北京100029

出　　处：《地球学报》2025年第2期343-360,共18页Acta Geoscientica Sinica

基　　金：国家科技重大专项项目(编号:2024ZD1001507);国家自然科学基金青年基金项目(编号:41672095);国家自然科学基金重点项目(编号:92062218)联合资助。

摘　　要：大兴安岭南段是我国北方最重要的锡多金属成矿区。边家大院、宝盖沟和毛登锡多金属矿床是其中典型代表,其矿体均与燕山期花岗质侵入岩有密切的空间关系。对上述矿床含矿花岗侵入岩,即边家大院石英斑岩,宝盖沟花岗岩以及毛登花岗斑岩进行锆石U-Pb测定,结果显示成岩年龄分别为(136.9±0.8)Ma,(143.6±0.8)Ma和(135.0±1.4)Ma,均侵位于早白垩世。全岩主量元素分析显示,这些花岗侵入岩都具有高硅、钾和钠,低钙、镁和钛的特征,为准铝质-弱过铝质、高钾钙碱性花岗岩。微量元素分析显示花岗岩具有富集大离子亲石元素而亏损高场强元素的特征。稀土元素分析显示它们均具有明显的负Eu异常。根据全岩地球化学特征及锆石TZr温度(753~796℃)判断,这些花岗岩属于高分异I型花岗岩。研究表明3个岩体_(εHf)(t)为–0.86~13.7,T_(DM2)=307~1240 Ma,锆石Hf同位素分析结果表明这些花岗岩主要为新元古代年轻地壳部分熔融形成。结合地球化学和地质年代学研究表明,大兴安岭南段早白垩纪高分异I型花岗岩具有较大的寻找锡矿的潜力。The southern Great Xing'an Range is the most important tin-polymetallic mineralization zone in Northern China,highlighted by the Bianjiadayuan,Baogaigou,and Maodeng deposits.These deposits are closely spatially associated with the Yanshanian granitic intrusions.Precision zircon U-Pb isotopic dating of ore-bearing intrusions revealed emplacement ages of(136.9±0.8)Ma,(143.6±0.8)Ma,and(135.0±1.4)Ma for the Bianjiadayuan quartz porphyry,the Baogaigou granite,and the Maodeng granitic porphyry,respectively.According to detailed major element analyses,these granitic intrusions were classified as metaluminous to weak peraluminous,high-K calc-alkaline granites.Trace element studies showed an enrichment in LILE and a depletion in HFSE of these intrusions,with pronounced negative Eu anomalies.We classified these granites as highly differentiated I-type granites,based on their whole-rock geochemical characteristics and Zr saturation temperature(753–796℃).Zircon Hf isotope analysis(_(εHf)(t)=–0.86–13.7,T_(DM2)=307–1240 Ma)indicated that these granitic predominantly originated from partial melting of Neoproterozoic juvenile lower crust.Geochemical and geochronological studies suggested that Early Cretaceous highly differentiated I-type granites in the southern Great Xing’an Range showed significant potential for tin exploration.

关 键 词：大兴安岭南段 锡矿 高分异花岗岩 早白垩世 

分 类 号：P595[天文地球—地球化学]