【作者】 孟兆贤；

【导师】 孙景贵；

【作者基本信息】 吉林大学 ， 地质工程， 2012， 硕士

【摘要】 黑龙江省东宁县洋灰洞子铜矿床是近几年发现的，作者在黑龙江省有色金属地质勘查七O二队工作期间，参与了项目有关的设计和野外生产工作。在收集和整理前人资料的基础上，通过两年多的野外生产和学习，着重研究了洋灰洞子铜矿床含矿石英脉的流体包裹体和矿石矿物中硫铅同位素特征，并讨论了洋灰洞子铜矿床的成矿物质来源、成矿流体运移及演化和成矿作用，最终确定洋灰洞子铜矿床的成因类型。通过本文的研究，得出了以下结论：（1）洋灰洞子铜矿床位于中国东部中生代环太平洋成矿带的北东端，黑龙江省东南部的完达山—太平岭金铜多金属成矿带上，区域性敦化—密山深大断裂的东侧。区域出露的地层主要为新元古界黄松群杨木组和阎王殿组，古生界下二叠统双桥子组和少量的中生界下侏罗统绥芬河组及第三系船底山玄武岩。研究区内岩浆活动强烈，以中深成的花岗岩为主，可分张广才岭期、印支晚期和燕山早期，主要岩石类型为花岗闪长岩、二长花岗岩、花岗斑岩、花岗闪长斑岩、流纹斑岩等。（2）洋灰洞子铜矿床的矿石矿物主要是有黄铜矿、黄铁矿、毒砂，还有少量辉钼矿、闪锌矿、方铅矿、磁黄铁矿等。围岩蚀变主要有硅化、黑云母化、绢（白）云母化、绿泥石化、碳酸盐化、绿帘石化等，与成矿关系密切的有黑云母化、硅化、绢（白）云母化。根据矿体的相互穿切关系、共生组合、矿石结构构造等特征，同时结合洋灰洞子铜矿床流体包裹体测温结果将洋灰洞子铜矿床划分为热液期和表生期两个成矿期，而前者又包括石英—黄铁矿阶段（Ⅰ）、石英—硫化物阶段（Ⅱ）、多金属硫化物阶段（Ⅲ）、碳酸岩阶段（Ⅳ）四个成矿阶段。（3）洋灰洞子铜矿床的流体包裹体主要为气液两相包裹体和少量透明无色的纯气相或纯液相包裹体。个体相对较小集中在4μm～10μm之间，气液比[V气/（V气+V液）]集中在10%～20%、大于20％、大于80％三个区间。均一温度变化于130℃～420℃之间，显示四阶段成矿特征即：早期石英—黄铁矿阶段（Ⅰ）的成矿温度在380℃～420℃之间；中期石英—硫化物阶段（Ⅱ）的成矿温度在330℃～370℃之间，此阶段是成矿的主要阶段之一；中晚期多金属硫化物阶段（Ⅲ）的成矿温度在190℃～290℃之间，为最主要的成矿阶段；晚期碳酸岩阶段（Ⅳ）的成矿温度在130℃～180℃之间，晶洞中偶见颗粒状黄铁矿等硫化物。成矿流体的盐度区间为0.87wt%NaCl～13.55wt%NaCl，平均值为5.57wt%NaCl，中值介于4.0wt%NaCl～8.0wt%NaCl之间；成矿流体的密度在0.56g/cm~3～0.98g/cm~3之间，平均值为0.84g/cm~3，中值为0.70g/cm~3～0.90g/cm~3；气液两相包裹体的压力区间为9.69MPa～32.82MPa；成矿深度区间为0.36km～1.22km，平均成矿深度为0.77km。综上所述，洋灰洞子铜矿床成矿流体具有中高温、低盐度、低压力与成矿浅的特征。（4）该矿床中与成矿密切相关的花岗闪长斑岩的锆石U-Pb年龄为194.8±1.9Ma，推断其成矿时代应为早侏罗世。成矿作用过程为：早侏罗世花岗闪长斑岩体上侵，提供了热量和少量岩浆热液，驱动阎王殿组千枚岩地层中的建造水，沿构造裂隙产生对流循环，同时在其循环过程中淋滤地层（主要为新元古界阎王殿组千枚岩）和侵入岩体，使其中成矿元素活化、迁移、富集，最终成矿物质由于温度、PH值等物理化学条件的改变，并在层间薄弱部位或构造破碎带中沉淀，形成铜矿体。（5）基于矿床地质特征，物质来源，流体演化及成岩成矿时代等方面的研究结果，初步确定洋灰洞子铜矿床为早侏罗世形成的中高温热液交代型铜矿床。更多还原

【Abstract】 The Yanghuidongzi copper deposit, located in the Dongning county,Heilongjiang province was found in recent years. I took part in related designand field work of the project when I was in Non-ferrous Metal GeologicalExploration702team, Heilongjiang province. Based on collected andorganized previous data, I have studied the deposit according to field workabout two years. The author mainly studied on characteristics of ore-bearingquartz-hosted fluid inclusion and S, Pb isotope from ore mineral of theYanghuidongzi copper deposit, and discussed source of metallogenic material,migration and evolution of ore-forming fluid, and metallogenesis. Finally, theauthor determined the genetic type of Yanghuidongzi copper deposit, anddraw the following conclusions according to research in this paper:(1) The Yanghuidongzi copper deposit is located in the northeast part ofMesozoic circum Pacific metallogenic belt, east China, the southeastHeilongjing of Wandashan-Taipingling gold, copper polymetallic metallogenicbelt, east of Dunhua-Mishan fault. The exposed stratum mainly are theNeo-proterozoic Huangsong complex Yangmu group and Yanwangdian group,Paleozoic Lower Triassic Shuangqiaozi group and less Mesozoic LowerJurassic Suifenghe group, as well as Cenozoic Chuandishan basalt. Themagmatism in the area is intensity and mainly on mesogene granite. Thegranite can be classified into three periods: Zhangguangcailing epoch, LateIndo-Chinese epoch and Late Yanshanian. The rock type is mainly ongranodiorite, monzonite granite, granite porphyry, porphyritic granodiorite and porphyritic rhyolite.(2) The ore mineralogy is dominated by chalcopyrite, pyrite, arsenopyrite,with minor molybdenite, sphalerite, galena, pyrrhotite. Wall-rock alterationassociated with mineralization consists of biotite development, silicificationand sericitization. Four stages of mineralization have been identified usingmineral paragenetic relationships:(I) a quartz–pyrite stage,(II) aquartz–sulfide stage,(III) a polymetallic sulfide stage, and (IV) a carbonatitestage.(3) The fluid inclusions from the Yanghuidongzi copper deposit isdominated by gas–liquid inclusion and minor colorless pure gaseous or pureliquid inclusions. The fluid inclusions are relatively small and focus on4μm–10μm. The ratio of gas and liquid focus on10%–20%,＞20%and＞80%. The homogenization temperature vary from130℃to420℃with fourstages of metallogenic characteristic: a quartz–pyrite stage (I) withmetallogenic temperature of380℃–420℃, a middle quartz–sulfide stage (II)with metallogenic temperature of330℃–370℃, and this stage is one of mainmetallogenic stages. The middle–late polymetallic sulfide stage (III) withmetallogenic temperature of190℃–290℃, and this stage is mainmetallogenic stage. The late a carbonatite stage (IV) with metallogenictemperature of130℃–180℃and granulate pyrite was observed in geode.The salinity of ore–forming fluid is range from0.87%to13.55wt%NaCl andmean value is5.57wt%NaCl. The mid–value is range from4.0%to8.0wt%NaCl. The density of ore–forming fluid is range from0.56g/cm~3to0.98g/cm~3and mean value is0.84g/cm~3. The mid–value is range from0.70g/cm~3to0.90g/cm~3. The pressure for gas–liquid inclusion is range from9.69MPa to32.82MPa. The depth for metallogenesis is range from0.36km to1.22kmand mean value is0.77km. In conclusion, the ore–forming fluid for theYanghuidongzi copper deposit is characterized by medium-high temperature,low salinity, low pressure and low metallogenic depth.(4) The zircons from porphyritic granodiorite, which is closely related tometallogenesis yielded U–Pb age of194.8±1.9Ma, and inferred thatmetallogenic epoch is the Early Jurassic. The process of metallogenesis isdiscussed following: The intruded upward of the Earlyl Jurassic porphyriticgranodiorite provided heat and minor magmatic hydrothermal, which drived formation water from the Yanwangdian group phylite migrated along tectonicfissure. Meanwhile, magmatic hydrothermal leached stratum (theNeo-proterozoic Yanwangdian group phylite) and intrusion rock, which madeore–forming elements activated, migrated and enriched. Then theore–forming elements deposited in structural fracture zone and formed copperdeposit with changing of physical and chemical conditions of metallogenicmaterials, such as temperature, PH value.(5) Based on research into geologic characteristic, material source,evolution of fluids and petrologenesis and metallogenesis, we preliminaryconfirmed that the Yanghuidongzi copper deposit is a medium-hightemperature pyrometasomatic deposit formed in the Early Jurassic.更多还原