西天山阿希金矿浊沸石化与古地热成矿流体系统的初步研究

通过野外考察、显微镜下薄片鉴定、X射线物相分析和矿物红外光谱等研究,确定了阿希金矿浊沸石化的普遍存在;根据浊沸石化发生的规律及其与矿床形成的关系,确定浊沸石化主要见于矿体的上部和外围,发育在地热流体系统的边缘和演化晚期,可作为寻找浅成低温热液型金矿的标志之一。导致阿希金矿浊沸石化的流体性质与热泉型金矿成矿流体和现代地热田类似,流体作用发生在石炭纪,证明西天山地区具有良好的浅成低温热液型金矿的形成和保存环境,因此找矿前景较好。     

陕西凤县八卦庙金矿流体包裹体的成分特征

对赋存于南秦岭泥盆系浅变质碎屑岩中的陕西凤县八卦庙金矿主成矿阶段的石英中流体包裹体进行研究，发现八卦庙金矿成矿流体盐度变化较大，从中等偏低盐度到富含子矿物的高盐度流体包裹体均有分布，通过光学显微镜，EPMA、SEM/EDS观察发现子矿物主要为黄铁矿，石盐及一些成分复杂的子矿物，LRM分析流体包裹体成分以富含CO2为特征，除此之外还检出了CO，CO2，CH4，H2S，C2H4等，表明矿床成矿流体具有相对还原的复杂物理化学条件，不同于一般的热液金矿床。     

甘肃省文县阳山金矿带安坝里南矿段流体包裹体研究

阳山金矿不同温度盐度的成矿流体发生了混合。两种流体的混合、冷却、稀释及pH、EH值的改变、温度压力的变化,造成沉淀,成矿物质来源于围岩。沉淀区域为裂隙发育区,属层间破碎带或裂隙发育带控矿。     

辽宁凌海市金家金矿床流体包裹体研究

金家金矿床位于辽宁省凌海市,包括刘屯和金屯两个矿体,矿石类型主要为硫化物石英脉型.对采取地表、坑道及钻孔中的含金石英脉样品进行包裹体测温和成分分析,以研究矿床形成的物理化学条件.结果表明,成矿只有一期,成矿流体是含CO2 及Ca2+、Na+、Cl-的NaCl-H2O-CO2体系.均一温度直方图呈单峰式,成矿温度平均为2...     

北淮阳成矿带东段东溪低硫型浅成热液金矿床：来自蚀变矿物、流体包裹体和氢氧同位素的证据

北淮阳成矿带东段早白垩世晓天火山盆地产出戴家河金矿、东溪金矿、隆兴金矿等一系列浅成低温热液型金矿床.主要针对晓天火山盆地中规模最大的东溪金矿开展详细的围岩蚀变观察、X射线衍射矿物鉴定、流体包裹体显微测温、激光拉曼探针和氢氧同位素分析.X射线衍射矿物鉴定证实东溪金矿发育有低硫型浅成低温热液型金矿中特征性蚀变矿物-冰长石的存在,结合普遍发育的硅化-碳酸盐化,推断东溪金矿形成于偏碱性的环境.流体包裹体岩相学研究表明,东溪金矿主要发育富液相的气液两相水溶液包裹体,成矿期流体的均一温度范围为216～254℃,盐度为0.2 wt.%～1.7 wt.%NaCl eq.,属中低温度、低盐度的流体.成矿后期流体的均一温度明显降低,其盐度也略有降低,显示了更广泛的大气降水的参与.氢氧同位素数据显示,东溪金矿的成矿流体远离岩浆水的范围,而靠近大气降水演化线.氢氧同位素数据,结合中低温度、低盐度的流体特征,表明循环的大气降水广泛参与了成矿作用.对蚀变矿物、流体包裹体和氢氧同位素分析结果表明,东溪金矿是典型的低硫型浅成低温热液金矿床.     

小秦岭金矿田含金石英流体包裹体中的有机成分及其与金矿化的关系

本文首次对小秦岭金矿中含金石英流体包裹体的有机成分进行了研究,探讨了包裹体中的有机质与金矿化之间的关系。结果表明,有机质对金矿的形成起到了重要作用。文中依据含金石英包裹体中有机成分的时空变化,提出了小秦岭金矿深部金矿化的某些评价标志。     

贵州省天柱县地豆冲金矿流体包裹体特征研究

通过对流体包裹体镜下观察、温度和成分测定,获取贵州省天柱县地豆冲金矿石英包裹体以原生液体包裹体为主,大小3-16μm,气液比集中于5%-15%;流体包裹体的均一温度在142.3-307.1℃;流体盐度为2.74-10.11 wt%NaCl,密度为0.81-0.93 g/cm3,气相成分以H2O为主,含少量CO2、N2、CH4;成矿压力为265.25-451.67 bar,成矿深度为1001.43-1705.25 m.该矿床属成矿压力低的浅成中低温热液矿床,其成矿流体具低盐度、低密度的特征。     

河南老湾金矿床流体包裹体及稀土元素地球化学研究

老湾金矿床产于中元古界龟山组,主要岩性为二云石英片岩和斜长角闪片岩。矿体受NWW向的韧脆性构造和NE向及NW向的次级构造控制,呈似层状、层状和脉状产出。矿床流体包裹体研究表明,成矿流体具有中-低温度、低盐度和低密度特征;流体包裹体液相成分中富含K+、Na+,二者比值显示成矿流体主要为岩浆水。矿床、围岩和老湾花岗岩的稀土元素研究认为,成矿物质主要来源于围岩和花岗岩。     

贵州省锦屏县八克金矿流体包裹体地球化学研究

贵州省锦屏县八克金矿流体包裹体以原生包裹体为主,少量次生包裹体。包裹体大小在2-10μm之间,个别大于10μm;以含CO2三相包裹体为主,其次气液两相包裹体,少量纯CO2包裹体;成矿流体包裹体的均一温度集中在240℃-300℃,气液两相包裹体平均盐度4.29 wt%NaC l-6.51 wt%NaC l,密度为0.75 g/cm3-0.92 g/cm3,三相包裹体平均盐度:1.91 wt%NaC l-5.11 wt%NaC l,密度为0.62 g/cm3-0.97 g/cm3,得出结论是八克金矿属于低盐度低密度的中温矿床。     

东营凹陷油气充注历史的流体包裹体分析

对东营凹陷胜坨和牛庄油田油气包裹体进行了分析,结合其构造发育史、沉积埋藏史、热史和生烃史等的综合研究,探讨了东萱凹陷油气成藏充注过程中油气运移的相态、运移通道及其成藏过程的时间。首次在东营发现的沸腾包裹体说明了胜坨油田呈现“突发式”成藏的可能性和牛庄油田砂岩体油气充注的时间是东营末期至馆陶期,牛庄油田牛２１井区的油气充注时间是东营末期至现今。     

新疆东天山典型金矿床成矿物质来源探讨

作者根据对新疆东天山典型金矿床的沉淀成矿环境、地球化学特征、稳定同位素特征等的系统分析和研究，论证了形成金矿床的硅质流体最初是一种以水为主要溶剂，以溶解态、胶体态氧化硅为主要溶质的高温高压(超临界态)溶液，其来源于地幔，是一种溶解了大量SiO2的地幔流体。而成矿元素主要来源于硅质流体上升运移过程中所经围岩，以致成矿物质来源具异源性。这对研究内生金矿床的成矿机制和成因有着十分重要的意义。     

Discovery and geological implication of rodingites derived from eclogites of ophiolites at Changawuzi, western Tianshan, China

We here report the first case of rodingites that were formed at the expense of eclogite enclosed in the ultramafic rocks of Changawuzi ophiolites. The rodingites contain a mineral assemblage of grossular, diopside, prehnite, chlorite, and relict omphacite and Fe-Mg-Al garnets. The presented data indicate that the formation of the rodingites resulted from a phase of secondary serpentinization during exhumation of the subducted oceanic plate. The rodingitization started at 370～410 ℃/6.5～8.5 kbar, while pervasive rodingitization took place under the condition of 200～350 ℃/4～6 kbar. The established PT path shows a retrograde track from eclogites to rodingites. We conclude that the process of rodingitization could also take place under subduction conditions in addition to its more common occurrence under ocean-floor metamorphic conditions.     

Fluid inclusions in whiteschist in the ultrahigh-pressure metamorphic belt of Dabie Shan, China

Hualiangting whiteschist in the Dabie Shan ultrahigh-pressure eclogite complex is a specific Mg-Al- rich metamorphic rock. Its protolith was a felsic dyke, which suffered replacement by high-pressure fluids during eclogite-facies metamorphism. Based on fluid inclusion results in whiteschist, primary high-pressure fluids are CO2-bearing aqueous solutions. Those prove that there exists CO2-H2O fluid during the ultrahigh-pressure metamorphism. Pseudosecondary H2O inclusions were trapped during ultrahigh-pressure exhumation, whereas secondary H2O inclusions were related to the latest evolutionary stage of the ultrahigh-pressure exhumation.     

新疆西准噶尔扎合金矿地质特征及成因

扎合金矿位于准噶尔板块萨吾尔晚古生代岛弧区的中南段,矿体赋存于海西晚期—印支早期侵入的中性闪长岩岩体及围岩接触部位.矿区内发育北西向和北东向两组断裂.北西向断裂既是成矿热液运移的通道,也是金元素富集成矿的场所,岩体为金矿提供了成矿物质和部分热液.根据矿体产出地质特征,扎合金矿属构造蚀变岩型金矿床;据成矿作用分析,该金矿属中低温热液金矿床.     

Fluid mineralization of the Dajing Sn-polymetal deposit： Evidence from LA-ICP-MS analysis of individual fluid inclusions

LA-ICP-MS analyses on single fluid inclusions trapped in fluorite and quartz from the Sn-Cu orebody of the Dajing deposit and from the Sn ore-body of the Huanggangliang deposit were conducted to trace the source and evolution of Cu-rich and Sn-rich fluids in the Dajing deposit using the Rb/Sr and Sn/Cu ratios of the fluids. The results show that the Cu-rich fluids in the Dajing deposit, relatively rich in Na and probably derived from deep-seated basic magma, contain Cu several to several tens of times more than Sn, and Sr several to several tens of times more than Rb, while the Sn-rich fluids, relatively rich in K and probably derived from high level granitic magma, contain Sn several to several tens of times more than Cu, and Rb several to several tens of times more than Sr. It is suggested that the Sn-rich and the Cu-rich fluids were mixed at the stage of moderate to low temperature and low salinity, resulting in the formation of Cu-Sn orebodies at the central part of the Dajing deposit.     

Zircon U-Pb age of granitic gneiss on Duku highway in western Tianshan of China and its geological implications

Granitic gneiss on Duku highway in western Tianshan has been dated by the U-Pb zircon method. When plotted on the concordia diagram, the results give linear data array and the upper intercept age of (882 ± 33)Ma, and the age was considered as the crystallization age of the protolith. Granitic gneiss has high ASI value (1.09), high LILE and LREE contents, significantly negative Eu depletion, distinctly negative Ba, Sr, P, Ti and Nb anomalies and indicate continental crust parentage, which is consistent with high initial⁸⁷Sr/⁸⁶Sr ratios value (0.7170) and very negative ε_Nd(t)=-14.1. The protolith magma is interpreted as a product of partial melting of the basement rocks of older basement crust.