西藏墨竹工卡县邦铺钼(铜)矿床辉钼矿稀土—微量元素特征及对成矿流体性质的指示   总被引：3，自引：0，他引：3  

王立强  唐菊兴  王登红  罗茂澄  陈伟  黄凡 《地质论评》2012,58(5):887-892

文章以西藏墨竹工卡县邦铺钼(铜)矿床辉钼矿为研究对象,采用高精度电感耦合等离子质谱( ICPMS)对辉钼矿进行了稀土和微量元素测试.测试结果显示辉钼矿具有轻稀土富集的右倾配分模式,轻重稀土内部分馏明显.辉钼矿稀土元素不同程度地出现铕负异常和铈负异常现象,分析得出其铕负异常可能是继承了成矿流体自身铕亏损的特征,而铈负异常...  相似文献   

青海省祁连县东沟铜矿床成矿特征及成因研究     

武鹏  马彦青  李向民  徐学义  余吉远  王国强  唐卓  韩媛 《矿床地质》2012,31(6):1337-1349

通过对东沟铜矿床的成矿特征、流体包裹体地球化学以及矿床成因研究,获得了如下认识:① 成矿环境为晚寒武世的大洋扩张脊环境,容矿岩石为蛇绿岩套上部的基性火山岩,矿床成矿金属组合为Cu-Zn(少量),围岩蚀变主要有硅化、绿泥石化、碳酸盐化及绿帘石化等,其中,硅化、绿泥石化与矿体的关系最为密切;② 对不同类型矿石中黄铁矿、黄铜矿的电子探针分析均表明,具有低温或中低温热液成矿的特征;③ 流体包裹体地球化学研究表明,该区成矿期石英中包裹体类型简单,仅有纯液体包裹体和液体包裹体,气相分数低,液体包裹体气相成分以CO₂为主,液相成分主要为H₂O;矿床成矿流体温度为150～200℃,盐度w(NaCl_eq)为13%～16%,密度为0.87～0.95 g/cm³;④ 矿床属于"塞浦路斯"型块状硫化物矿床。关键字 地球化学;成矿特征;流体包裹体;塞浦路斯型矿床;东沟铜矿;北祁连  相似文献   

超深井高温钻井液技术概况及研究方向的探讨   总被引：7，自引：0，他引：7  

胡继良 《地质与勘探》2012,48(1):155-159

[摘 要] 我国未来深部大陆科学钻探深度为12000m ～ 13000m,井底温度将达到350℃以上,钻井液将面临超高温高压环境,钻井液技术将面临严峻考验。本文重点介绍了国内外典型深井及超深井钻探和高温地热井钻探钻井液使用情况,提出了抗高温钻井液的主要技术难点是高温高压及污染条件下钻井液流变性、滤失量、润滑性控制。耐温250℃以上钻井液处理剂及体系、耐高温钻井液试验仪器和地面循环降温系统是超高温钻井液技术研究方向。  相似文献   

山东省埃子王家—原疃矿区成矿流体特征及流体来源     

杨柳 《地质与勘探》2012,48(2):217-226

[摘 要] 通过对埃子王家-原疃矿区流体包裹体岩相学、测温学及铅、硫同位素等的分析,研究其成矿流体性质和演化,并探讨矿床成矿流体和成矿物质来源,结果表明:①流体包裹体主要为气液两相包裹体;包裹体液相成分阳离子以K⁺、Na⁺、Ca²⁺、Mg²⁺为主,阴离子以SO²₄、Cl^-、F^-为主;气相成分以H₂O、CO₂、CH₄为主;②成矿流体均一温度、盐度分别为120～350℃,4. 26%～8. 66%,为中低温(200℃以下为70%)、低盐度的流体;③²⁰⁶Pb/²⁰⁴Pb 范围为16. 217～18. 034;²⁰⁷Pb/²⁰⁴Pb 范围为15.180～16.889;²⁰⁸Pb/²⁰⁴Pb 范围为36. 586～39. 987。分析认为,本区铅同位素来源应为壳幔混合源。  相似文献   

滇西马厂箐钼铜金矿床深部地质过程的系列成矿效应     

肖继雄 《地质与勘探》2012,48(3):546-561

[摘 要] 马厂箐钼铜金矿床是金沙江-哀牢山断裂带上与喜马拉雅期富碱斑岩有关的典型矿床之一,其成矿作用具有特殊性。本文应用透岩浆流体成矿理论,重点探讨了马厂箐钼铜金矿床深部地质过程中成岩与由地幔流体作用引发壳幔混染并形成系列成矿的关系。通过对马厂箐矿床成岩成矿时代的厘定、岩矿石稀土和微量元素、稀有气体及Pb-Sr-Nd 同位素研究,论证了成矿流体和岩浆流体均来自于富集地幔,这种成矿流体是包含于富碱岩浆并与其互不混溶的地幔流体。在上升运移过程中,地幔流体可随富碱岩浆的结晶成岩过程对岩体进行同步自交代蚀变而在斑岩体内或其深部形成矿床;也可与岩浆分离而独立运移,在岩体与围岩的接触带及地层围岩中进行交代蚀变成矿。在这一成岩成矿过程中, 引发并促进壳幔物质混染和叠加成矿,由此导致了马厂箐矿区成矿分带表现为从岩体到围岩、从高温到低温的不同矿种和不同类型的系列成矿效应。  相似文献   

阿姆河盆地卡洛夫-牛津阶碳酸盐岩储层地球化学特征和成岩流体分析   总被引：2，自引：1，他引：1  

郑荣才  刘合年  吴蕾  陈仁金  史建南  李凤杰 《岩石学报》2012,28(3):961-970

卡洛夫-牛津阶碳酸盐岩为土库曼斯坦阿姆河盆地主力天然气产层,以储层岩石学分析为基础,结合Fe、Sr、Mn微量元素和C、O、Sr同位素及流体包裹体地球化学特征,分析了储层成因和成岩流体性质,得出以下几点认识:(1)由厚壳蛤壳体测定的87Sr/86Sr比值在全球锶同位素地层曲线上可标定的年龄为157.2Ma,储层发育层位属于卡洛夫-牛津阶;(2)卡洛夫-牛津阶为一持续海侵-海退旋回,持续海侵期是礁、滩相储层形成期,而持续海退期为致密盖层发育期;(3)较高的Fe和Sr及较低的Mn含量,以及伴随成岩强度加大δ13C变化不大而δ18O向负值方向偏移的演化趋势,证明成岩作用发生在缺乏大陆淡水影响和以温度为主控因素的还原性封闭系统中;(4)综合同位素地球化学与流体包裹体和镜质体反射率特征,可确定洛夫-牛津阶碳酸盐岩仍处在中成岩阶段;(5)礁、滩相灰岩的溶蚀、埋藏白云化和充填缝、洞的方解石是不同成岩阶段的水-岩反应产物,成岩流体主要来自于深部富Sr的地层热卤水。  相似文献   

Mineral compositions and fluid evolution of the Tonglushan skarn Cu–Fe deposit,SE Hubei,east-central China     

《International Geology Review》2012,54(7):737-764

The Tonglushan Cu–Fe deposit (1.12 Mt at 1.61% Cu, 5.68 Mt at 41% Fe) is located in the westernmost district of the Middle–Lower Yangtze River metallogenic belt. As a typical polymetal skarn metallogenic region, it consists of 13 skarn orebodies, mainly hosted in the contact zone between the Tonglushan quartz-diorite pluton (140 Ma) and Lower Triassic marine carbonate rocks of the Daye Formation. Four stages of mineralization and alterations can be identified: i.e. prograde skarn formation, retrograde hydrothermal alteration, quartz-sulphide followed by carbonate vein formation. Electron microprobe analysis (EMPA) indicates garnets vary from grossular (Ad_20.2–41.6Gr_49.7–74.1) to pure andradite (Ad_47.4–70.7Gr_23.9–45.9) in composition, and pyroxenes are represented by diopsides. Fluid inclusions identify three major types of fluids involved during formation of the deposit within the H₂O–NaCl system, i.e. liquid-rich inclusions (Type I), halite-bearing inclusions (Type II), and vapour-rich inclusions (Type III). Measurements of fluid inclusions reveal that the prograde skarn minerals formed at high temperatures (>550°C) in equilibrium with high-saline fluids (>66.57 wt.% NaCl equivalent). Oxygen and hydrogen stable isotopes of fluid inclusions from garnets and pyroxenes indicate that ore-formation fluids are mainly of magmatic-hydrothermal origin (δ¹⁸O = 6.68‰ to 9.67‰, δD = –67‰ to –92‰), whereas some meteoric water was incorporated into fluids of the retrograde alteration stage judging from compositions of epidote (δ¹⁸O = 2.26‰ to 3.74‰, δD= –31‰ to –73‰). Continuing depressurization and cooling to 405–567°C may have resulted in both a decrease in salinity (to 48.43–55.36 wt.% NaCl equivalent) and the deposition of abundant magnetite. During the quartz-sulphide stage, boiling produced sulphide assemblage precipitated from primary magmatic-hydrothermal fluids (δ¹⁸O = 4.98‰, δD = –66‰, δ³⁴S values of sulphides: 0.71–3.8‰) with an extensive range of salinities (4.96–50.75 wt.% NaCl equivalent), temperatures (240–350°C), and pressures (11.6–22.2 MPa). Carbonate veins formed at relatively low temperatures (174–284°C) from fluids of low salinity (1.57–4.03 wt.% NaCl equivalent), possibly reflecting the mixing of early magmatic fluids with abundant meteoric water. Boiling and fluid mixing played important roles for Cu precipitation in the Tonglushan deposit.  相似文献   

The Qiyugou gold-bearing breccia pipes,Xiong'ershan region,central China: fluid-inclusion and stable-isotope evidence for an origin from magmatic fluids     

《International Geology Review》2012,54(1):25-45

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Mineralization and fluid evolution of the Jiyuan polymetallic Cu–Ag–Pb–Zn–Au deposit,eastern Tianshan,NW China     

《International Geology Review》2012,54(7):816-832

The newly discovered Jiyuan Cu–Ag–(Pb–Zn–Au) deposit is located in the southern section of the eastern Tianshan orogenic belt, Xinjiang, northwestern China. It is the first documented deposit in the large Aqikekuduke Ag–Cu–Au belt in the eastern Tianshan orogen. Detailed field observations, parageneses, and fluid inclusion studies suggest an epithermal ore genesis for the main Cu–Ag mineralization, accompanied by a complicated hydrothermal alteration history most likely associated with the multi-stage tectonic evolution of the eastern Tianshan. The Jiyuan Cu–Ag ore bodies are located along the EW-striking, south-dipping Aqikekuduke fault and are hosted by Precambrian marble and intercalated siliceous rocks. Early-stage skarn alteration occurred along the contact zone between the marble layers and Early Carboniferous diorite–granodiorite and monzogranite intrusions; the skarns are characterized by diopside–tremolite–andradite–pyrite–(magnetite) assemblages. Local REE-enriched synchysite–rutile–arsenopyrite–(clinochlorite–microcline–albite) assemblages are related to K–Na alteration associated with the monzogranite intrusions and formed under conditions of high temperature (310°C) and high salinity (19.9 wt.% NaCl). Subsequent hydrothermal alteration produced a series of quartz and calcite veins that precipitated from medium- to low-temperature saline fluids. These include early ‘smoky’ quartz veins (190°C; 3.0 wt.% NaCl) that are commonly barren, coarse-grained Cu–Ag mineralized quartz veins (210°C; 2.4 wt.% NaCl), and late-stage unmineralized calcite veins (140°C; 1.1 wt.% NaCl). Tremolite and Ca-rich scapolite veins formed at an interval between early and mineralized quartz veins, indicating a high-temperature, high-salinity (>500°C; 9.5 wt.% NaCl) Ca alteration stage. Fluid mixing may have played an important role during Cu–Ag mineralization and an external low-temperature Ca-rich fluid is inferred to have evolved in the ore-forming system. The Jiyuan auriferous quartz veins possess fluid characteristics distinct from those of the Cu–Ag mineralized quartz veins. CO₂-rich fluid inclusions, fluid boiling, and mixing all demonstrate that these auriferous quartz veins acted as hosts for the orogenic-type gold mineralization, a common feature in the Tianshan orogenic belt.  相似文献   

Geological and geochemical constraints on genesis of the Liziyuan gold-dominated polymetal deposit,western Qinling orogen,central China     

《International Geology Review》2012,54(16):1944-1966

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