【作者】 贾志业；

【导师】 薛春纪；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2011， 硕士

【摘要】 莱历斯高尔-肯登高尔一带是西天山地区重要的铜钼矿集区,近年来受到多方关注。本文通过莱历斯高尔-3571铜钼矿、肯登高尔铜钼矿两个典型矿床,在区域地质、矿区地质基础上,利用岩相学、矿相学、岩石及矿床地球化学、年代学等方面来研究岩浆过程和铜钼成矿作用。莱历斯高尔-3571铜钼矿矿体呈脉状、板状和透镜状产在花岗闪长斑岩体顶部或边部、接触带和附近围岩中,具典型斑岩型矿床矿化蚀变分带特征。肯登高尔铜钼矿矿体呈板状、不规则脉状和透镜状产在花岗闪长岩与上石炭统碳酸盐岩外接触带矽卡岩中,受接触带构造控制,铜钼硫化物内生热液成矿经历了矽卡岩期和石英-硫化物期,属矽卡岩型铜钼矿。莱历斯高尔-3571铜钼矿花岗闪长斑岩小岩体具有高硅、低镁、富铝、富碱、高钾钙碱性等特点,肯登高尔铜钼矿花岗闪长岩体具高硅、富碱、低镁、高钙、准铝质、高钾钙碱性的特点,表明岩浆的高酸、富碱、高钾地球化学环境有利于Cu、Mo的富集。岩石化学成分分析显示,岩体形成均与准噶尔洋壳向伊犁板块这一俯冲过程有关。流体包裹体显微测温和激光拉曼探针分析显示,莱历斯高尔-3571铜钼矿成矿流体早阶段为高中温、中低盐度的NaCl-H₂O体系,随后演化为高中温、低盐度的NaCl-H₂O-CO2体系,晚阶段演化为中温、低盐度NaCl-H₂O体系;肯登高尔铜钼矿主成矿流体属于中低温、低盐度、低密度的NaCl-H₂O流体。H、O同位素研究表明,成矿流体起源于岩浆水,成矿晚阶段不同程度混入大气降水。S、Pb同位素组成及辉钼矿Re含量研究表明,莱历斯高尔-3571铜钼矿、肯登高尔铜钼矿成矿与洋壳俯冲过程中的岩浆活动有关,成矿金属可能来自于俯冲洋壳熔融的岩浆。莱历斯高尔-3571铜钼矿成岩成矿于晚泥盆世-早石炭世;肯登高尔花岗闪长岩体锆石SHRIMP U-Pb年龄为313±4Ma,辉钼矿Re-Os等时线年龄为313.9±2.5Ma,成岩成矿于晚石炭世。显示铜钼矿成岩成矿于晚泥盆世-晚石炭世。综上所述,晚泥盆世-晚石炭世的高酸、富碱、高钾岩体对寻找斑岩-矽卡岩型铜钼矿具有指示意义。更多还原

【Abstract】 As a important Cu-Mo ore concentration area in western Tianshan, the Lailigao`er-Kendenggaoer region is paid much attention to. Based on regional geology and mine geology, the magmatic processes and Cu-Mo mineralization by petrography, mineralography, geochemistry of petrology and ore deposit, geochronology of Lailisigao`er-3571 Cu-Mo deposit and kendenggaoer Cu-Mo deposit are studied in this paper.In the Lailisigao`er-3571 Cu-Mo deposit, the Cu-Mo sulfide ore-body with veins, tabular and lens in shape occurring in the top or edge parts of the granodiorite porphyry, contact belts and the wall-rock nearby, shows the typical mineralized alteration zoning characteristics of Porphyry deposit. The Kendenggaoer Cu-Mo ore bodies with tabular, laminated and lenticular shape occurs in the outer contact belt between late Carboniferous granodiorite and carbonate rocks of Upper Carboniferous, controlled by contact zone structure. The Kendenggaoer Cu-Mo sulfide endogenic mineralization has obviously experienced two stages,skarn stageand quartz-sulfide stage, showing the characteristics of skarn-type Cu-Mo deposit.Geochemical analysis shows that the Lailisigao`er granodiorite porphyry is rich in Si, Al, K and Na, and poor in Mg, with high-K calc-alkaline characteristic and the Kendenggaoer granodiorite has a relatively high quantity of SiO₂, Na₂O+K₂O and CaO, and low quantity of MgO, with metaluminous and high-K calc-alkaline characteristic. The characteristic of petrology geochemistry shows that the high-acid, rich-alkali, high-potassium magma is beneficial to the Cu-Mo enrichment, and the formation of rock mass happened after Junggar oceanic crust subducted to Kazakhstan-Yili plate.The analysis of the microthermometry and Laser Raman spectroscopy shows that the ore-forming fluid of Lailisigao`er-3571 Cu-Mo deposit in the early stage is a NaCl-H2O system, which has high-middle temperature, mid-low salinity, and then evolves a H2O-NaCl-CO<sub>2</sub> system, which has high-middle temperature, low salinity, and continuing evolves into a NaCl-H<sub>2</sub>O system, which has middle temperature, low salinity. The main ore-forming fluid of Kendenggaoer is a NaCl-H<sub>2</sub>O system, which has mid-low temperature, low salinity and density. The study of H<sup>-</sup>, O-isotopic composition shows that the ore-forming fluid is originated from magmatic water, with a little mixing of precipitate water in the late stage.The study of S-, Pb-isotopic composition and the Re content of the molybdenite of Lailisigao`er-3571 Cu-Mo deposit and Kendenggaoer Cu-Mo deposit shows that the ore-forming process is related to magmatic activity in the process of ocean crust subduction, and the ore-forming metals may come from the subduction ocean melting magma.The forming of the Ores-Bearing Porphyries and ore-bodies in the Lailisigao`er-3571 Cu-Mo deposit occurs in the late Devonian or early Carbiniferous. In the Kendenggaoer Cu-Mo deposit, the granodiorite is dated as 313±4Ma by Zircon SHRIMP U-Pb method, and the model age and isochron age of molybdenite Re-Os are 315.4±1.8Ma and 313.9±2.5Ma. The study of chronology shows rock mass and ore body are formed in the late Devonian or late Carbiniferous in the Lailisigao`er-Kendenggaoer region.To sum up, the high-acid, rich-alkali, high-potassium rock mass in the late Devonian or late Carbiniferous has indicative significance for the exploration of prophyry - skarn type Cu-Mo deposit.更多还原