【作者】 赵华雷；

【导师】 孙丰月； 任云生；

【作者基本信息】 吉林大学 ， 矿物学岩石学矿床学， 2014， 博士

【摘要】 吉黑东部地区地处西伯利亚板块和华北板块之间的中亚造山带东段，是一个经历了古亚洲洋构造域和太平洋构造域叠加转换的复杂构造区，成矿地质条件优越，矿产资源丰富。本文选择该区近年来找矿取得较大突破，但理论研究相对薄弱的钨矿床为研究对象，通过杨金沟、五道沟、白石砬子、翠宏山和羊鼻山等典型矿床地质地球化学特征、成矿流体特征、成岩成矿时代和构造背景等研究，确定了区内钨矿床的成因类型，讨论了不同矿床的成岩成矿物质来源和成矿地球动力学背景。取得的主要成果如下：1.对东北地区近年来新发现的首个大型钨矿床—珲春杨金沟白钨矿矿床进行了系统研究。首次提出该矿床属国内外少见的含白钨矿石英脉型，时空及成因上与二叠纪末期I-S型过渡花岗岩密切相关，成矿时代为三叠纪（热液白云母40Ar/39Ar年龄（230.79±1.19）Ma），成岩成矿物质具有深源性，成岩成矿作用与兴蒙造山带东段古生代末期古亚洲洋的俯冲作用有关。2.根据矿床成因，将本区钨矿床划分为热液脉型和矽卡岩型两种。热液脉型矿床的主矿体一般呈脉状发育于地层或岩体中，矿石矿物组成较为简单，围岩蚀变主要有硅化、云英岩化、高岭土化、白云母化和绿泥石化；矽卡岩型钨矿床的主矿体一般呈扁豆状和透镜状产于中酸性侵入岩和地层的接触带上，围岩蚀变主要为矽卡岩化、硅化、绿泥石化、绿帘石化、高岭土化、碳酸盐化、萤石化等，根据矿石中的矿物组合，进一步分为独立型和共（伴）生型矽卡岩型钨矿床。3.热液脉型钨矿床与成矿关系密切的岩体主要为花岗闪长岩，具有髙硅、富铝、富碱的特征，显示为准过铝质-弱过铝质钙碱性花岗岩的I型或I-S型过渡花岗岩特征。矽卡岩型钨矿床成矿相关岩体可分为两类，第一类为I型花岗岩，以石英闪长岩、石英二长岩为代表，为准铝质碱钙性系列岩石，富集轻稀土元素，亏损重稀土元素和Nb、Ta等高场强元素；第二类以混合岩化片麻状花岗岩为代表的与S型花岗岩，为过铝质富钾钙碱性系列岩石，富集轻稀土元素和Rb，亏损重稀土元素和Ba、Sr、Nb、Ta、Ti等元素。4.不同矿床主成矿阶段流体包裹体、H-O同位素研究结果表明，热液脉型钨矿床包裹体气相组分主要为H2O、CO2和N2，偶见少量的CH4，成矿流体属NaCl-H2O-CO2体系，主要来自岩浆水。矽卡岩型钨矿床包裹体中的气相成分主要为H2O和CO2，偶见少量的CH4等，成矿流体属NaCl-H2O体系，主要为岩浆水和大气降水的混合。白钨矿单矿物的稀土、微量元素分析结果显示，热液脉型钨矿床中白钨矿单矿物的轻重稀土分馏不明显，并具有强烈的正Eu异常，显示为Ⅱ型白钨矿的特征，成矿物质来源较深；矽卡岩型钨矿床白钨矿单矿物具有一定程度的轻重稀土分馏，并以弱的正Eu或负Eu异常为特征；成矿物质与赋矿地层和成矿岩体具有密切联系。5.成岩成矿年代学研究显示，以杨金沟矿床为代表的热液脉型钨矿床形成于二叠纪晚期-三叠纪早期，成矿年龄约为（230.79±1.19）Ma。矽卡岩型钨矿床明显分为两期，早期以佳木斯地区的羊鼻山铁钨矿床为代表，成矿相关岩体的锆石U-Pb年龄为（507.6±1.0）Ma；晚期以翠宏山钨钼多金属矿床和白石砬子钨矿床为代表，白石砬子矿床成矿岩体的侵位年龄为（198.27±0.80）Ma，翠宏山矿床辉钼矿Re-Os等时线年龄为（198.9±3.7）Ma。6.代表性矿床的成岩成矿时代、成矿岩体的岩石地球化学特征及区域构造演化的综合研究表明，吉黑东部热液脉型钨矿床形成于晚二叠世-三叠世时期古亚洲洋向东北地块群俯冲作用有关的活动大陆边缘构造背景，成岩成矿物质应为壳源或壳幔混合源。以翠宏山和白石砬子为代表的早侏罗世矽卡岩型钨矿化主要发生于岛弧活动大陆边缘环境，其成岩成矿物质为壳幔混合源，形成于早侏罗世太平洋板块向欧亚板块俯冲的动力学背景下；以羊鼻山为代表早古生代钨矿化形成于同碰撞的构造环境，成岩成矿物质为壳源，与早奥陶世佳木斯地块与松嫩-张广才岭地块之间的陆陆碰撞有关。更多还原

【Abstract】 Eastern Jilin and Heilongjiang Provinces is located in the east part of Central AsiaOrogenic Belt, situated between the Siberian Plate and North China Plate. This area is acomplex tectonic region that experienced superposition activities of Paleo Asian Oceanand Pacific Ocean tectonic domain, which resulted in advantageous metallogenicgeological conditions and abundant mineral resources. Geological prospecting of tungstendeposits in recent years has made obvious breakthroughs in the area, but the theory level isrelatively low. This thesis focuses on the geological and geochemical characteristics,ore-forming fluid, geochronology and tectonic settings of typical deposits, such asYangjingou, Wudaogou, Baishilazi, Cuihongshan, Yangbishan, and discusses their theore-forming materials source and geodynamic settings. Such major conclusions are drawnas followings.1. The Yangjingou scheelite deposit recently discovered in Hunchun area, firstlarge-scale tungsten deposits in Northeast China, has been systematically studied. Thedeposit is identified as scheelite-quartz vein type which is rare type in both at home andabroad. It’s proved that Yangjingou deposit is closely related to Late Permian I-S transitiontype and formed in Triassic (40Ar/39Ar age of hydrothermal muscovite is（230.79±1.19）Ma). The diagenetic and metallogenetic material of this deposit was derived from the deepsource. Moreover, the diagenesis and mineralization of Yangjingou deposit are associatedwith the subduction of Paleo Asian Ocean to Xing’an-Mongolia Orogenic Belt in latePaleozoic.2. According to their ore genesis, tungsten deposits in the area can be divided into hydrothermal vein type and skarn type. The major orebodies of hydrothermal vein typedeposits are usually hosted by stratum or Late Paleozoic granitic intrusions, and aregenerally scheelite-quartz veins. The mineral composition of the ore is relatively simple.Wall-rock alterations include silicification, greisenization, kaolinization, muscovitizationand chloritization. The orebodies of skarn deposits are usually lenticular and are controlledby contact zone between granites and the stratum. Wall-rock alteration types includeskarnization, silicification, chloritization, epidotization, kaolinization, carbonatization andfluoritization. The skarn type can be further divided into independent skarn type andaccompanying skarn type thanks to ore mineral assemblages in these deposits.3. Granite intrusions associated with hydrothermal vein type tungsten mineralizationare mainly granodiorite. These rocks have high-Si, Al and alkali-rich, and display thefeatures of bequasi-peraluminous/weakly peraluminous calc-alkaline series, which areusually I type granites or I-S transition type granites. Granite associated withmineralization of skarn mineralization can be divided into two groups, the first is I-type,represented by quartz diorite or quartz monzonite, and the second is S-type, represented bymigmatized gneissic granite. Quartz diorite or quartz monzonite belongs to bequasi-aluminous calc-alkaline series, have enrichment of LREE and depletion of HREE and thehigh field-strength element (Nb, Ta etc). Migmatized gneissic granite belongs toperaluminous calc-alkaline series, have enrichment of LREE, Rb and depletion of HREE,Ba, Sr, Nb, Ta, Ti etc.4. Studies on fluid inclusions and H-O isotope from the main mineralization stage ofdifferent deposits show that gas components of fluid inclusions from hydrothermal veintype deposits are mainly H2O, CO2and N2, and occasionally small amounts of CH4. Theore-forming fluid of hydrothermal vein-type deposits are the NaCl-H2O-CO2system andmainly from magmatic water. Gas components of fluid inclusions from skarn deposits aremainly H2O, CO2and occasionally a small amount of CH4, which indicates that theore-forming fluid of skarn deposits belongs to the NaCl-H2O system and the mixture ofmagmatic water and meteoric waters.Rare earth element and trace element analysis of the scheelite show that scheelitesfrom hydrothermal vein-type tungsten deposits have no fractionation of LREE and HREEand a strong positive Eu anomaly, show the characterization of Ⅱ-type which originated from deep source. Scheelites from skarn deposits have obviously fractionation of LREEand HREE and a weak Eu anomaly (positive or negative), and ore-forming material isclosely related with the ore-bearing stratum and metallogenetic rock.5. Diagenetic and metallogenetic ages of different tungsten deposits show thathydrothermal vein type deposits (represented by Yangjingou deposit) were formed in thelate Permian to early Triassic, and the metallogenic age was determined to230.79±1.19Ma. Skarn tungsten deposits are clearly divided into two phases, the earlier isrepresented by Yangbishan tungsten deposit in Jiamusi region, zircon U-Pb ages ofmetallogenetic intrusion in Yangbishan deposit is determined to (507.6±1.0) Ma. Thelater is represented by Cuihongshan W-Mo polymetallic deposit and Baishilazi tungstendeposit. The emplacement age of metallogenetic granitic intrusion from Baishilazi depositwas (198.27±0.80) Ma, and molybdenite Re-Os isochron age of Cuihongshan deposit is(198.9±3.7) Ma.6. By comprehensive studies of diagenetic and metallogenetic age, geochemicalcharacteristics of representative deposits and tectonic evolution, it can be concluded thathydrothermal vein-type tungsten deposits in Eastern Jilin and Heilongjiang Provincesformed at island-arc active continental margin in Late Permian-Triassic period, when thesubduction of Paleo Asian Ocean to the northeast block groups played an important role intectonic evolution of this area. Early Jurassic skarn deposits, represented by Cuihongshanand Baishilazi, occurred at island-arc active continental margin, with diagenetic andmetallogenetic material from crust-mantle mixed source, formed under the subduction ofthe Pacific plate to the Eurasian Plate including the study area in early Jurassic. EarlyPaleozoic skarn deposit represented by Yangbishan formed under the tectonic setting ofsyn-collisional, with diagenetic and metallogenetic material from crust, and is closelyrelated to the continental collision between the Jiamusi Massif and Songnen Massif inEarly Ordovician.更多还原