黑龙江省完达山地区河口林场斑岩型锡多金属矿床花岗斑岩的形成年代、岩石成因及构造背景  

Geochronology, petrogenesis and tectonic setting of the granite porphyry related to Hekoulinchang tin polymetallic deposit in Wandashan area, Heilongjiang Province

作　　者：郝宇杰[1,2] 任云生 史雨凡[1] 商青青 孙振明 高煜 王崇一 杨群 HAO YuJie;REN YunSheng;SHI YuFan;SHANG QingQing;SUN ZhenMing;GAO Yu;WANG ChongYi;YANG Qun(College of Earth Sciences,Jilin University,Changchun 130061,China;Key Laboratory of Mineral Resources Evaluation of Northeast Asia,Ministry of Natural Resources,Changchun 130061,China;Institute of Disaster Prevention,Sanhe 065201,China;School of Prospecting&Surveying Engineering,Changchun Institute of Technology,Changchun 130021,China)

机构地区：[1]吉林大学地球科学学院,长春130061 [2]自然资源部东北亚矿产资源评价重点实验室,长春130061 [3]防灾科技学院,三河065201 [4]长春工程学院勘察与测绘工程学院,长春130021

出　　处：《岩石学报》2020年第3期837-855,共19页Acta Petrologica Sinica

基　　金：国家重点基础研究发展计划项目(2017YFC0601304);自然资源部东北亚矿产资源评价重点实验室开放基金课题(DBY-ZZ-18-05)联合资助。

摘　　要：黑龙江省宝清县河口林场锡多金属矿床位于兴蒙造山带东段的完达山地体内,为东北地区东部首个斑岩型锡多金属矿床。该矿床锡、银、铅、锌的平均品位分别为0.27%、122.89g/t、0.84%、1.43%,其中锡、银资源量达到中型,铅锌可达小型矿床规模。锡多金属矿体与花岗斑岩体具有密切的空间和成因关系,多呈细脉状、网脉状产在花岗斑岩体内部及其与上三叠统大佳河组硅质岩的侵入接触带两侧。野外地质调查和室内研究表明,矿区内的含矿花岗斑岩为锡多金属矿化的成矿岩体。该花岗斑岩的LA-ICP-MS锆石U-^Pb年龄为118.0±1.1Ma,表明其形成于早白垩世晚期。岩石地球化学特征研究表明,花岗斑岩中SiO2、K2O含量高,Fe2O3T、MgO、CaO以及过渡族元素含量低,属高钾-中钾钙碱性系列的Ⅰ型花岗岩。锆石εHf(t)为+3.4^+7.4,二阶段Hf模式年龄(tDM2)为701~956Ma。花岗斑岩的铅同位素组成为206^Pb/204^Pb=18.414~18.460、207^Pb/204^Pb=15.591~15.596、208^Pb/204^Pb=38.470~38.761,具有造山带及与俯冲过程相关的性质;^Sr初始值(87^Sr/86^Sr)i比值为0.708136~0.708331,εNd(t)值为-2.0^-3.0。根据岩石的元素地球化学和同位素地球化特征,判断河口林场含矿(成矿)花岗斑岩的初始岩浆源于基性新生下地壳物质的部分熔融,同时受到俯冲带浅部沉积物质的混染,结合区域构造演化资料分析认为,河口林场花岗斑岩及相关的斑岩型锡多金属矿化的构造背景可能与古太平洋板块向欧亚大陆板块的俯冲作用密切相关。The Hekoulinchang tin polymetallic deposit in Baoqing County of Heilongjiang Province is the first one discovered in the eastern part of the Northeast China.Tectonically,this deposit is located in Wandashan Terrane of eastern Xing'an-Mongolian Orogenic Belt.Its average grades of tin,silver,lead and zinc are 0.27%,122.89g/t,0.84%and 1.43%,respectively.This deposit is a medium-sized tin-silver deposit,and small-sized lead-zinc deposit.The thin-vein and stockwork tin polymetallic ore bodies are dominantly hosted within the granite porphyry body and its contact zone with the Upper Triassic Dajiahe Formation.According to the detailed field geological survey and data analysis,the ore-hosting granite porphyry should be the metallogenic intrusion.LA-ICP-MS zircon U-Pb dating of the granite porphyry yields an age of 118.0±1.1Ma,indicating that the intrusion emplaced at late Early Cretaceous.Its petro-geochemical characteristics show that the granite porphyry belongs toⅠ-type granite and high-medium-K calc-alkaline series,characterized by high contents of SiO2 and K2O,low contents of Fe2O3T,MgO,CaO,and transition elements.The zircon Hf isotope compositions of the granite porphyry samples indicate that the zircon has positiveεHf(t)values(+3.4^+7.4),and the two-stage Hf model age(tDM2)of 701~956Ma.The whole-rock lead isotope in granite porphyry has the characteristics of those in orogenic belt and subduction zone,as 206^Pb/204^Pb=18.414~18.460,207^Pb/204^Pb=15.591~15.596,208^Pb/204^Pb=38.470~38.761.The initial ^Sr value(87^Sr/86^Sr)i of the granite porphyry is 0.708136~0.708331,and the value ofεNd(t)is-2.0^-3.0.Due to studies on the petro-geochemistry and ^Sr-Nd-^Pb-Hf isotopes,it can be concluded that the original magma of the Hekoulinchang granite porphyry was mainly derived from partial melting of the basic juvenile lower crustal material and mixed with upper sedimentary materials in a subduction zone.Based on isotope dating and geochemical data in this paper,as well as knowledge of the regional tectonic evolution,it

关 键 词：河口林场斑岩型锡多金属矿床 花岗斑岩 锆石U-PB年龄 岩石地球化学 Sr-Nd-Pb-Hf同位素 黑龙江完达山地区 

分 类 号：P588.13[天文地球—岩石学] P597.3[天文地球—地质学]