地幔流体的交代作用——来自碱性正长岩及其深源岩石包体的证据

滇西玉龙县小桥头硅化霓辉正长斑岩中,含有较多镁铁-超镁铁质深源包体岩石。经岩相学和电子探针及扫描电镜分析发现,伴随交代蚀变,寄主岩和各类镁铁-超镁铁质包体岩石中,普遍发育沿粒间和矿物晶体裂隙或解理纹贯入或穿插的黑色不透明物质,主要由微晶硅酸盐矿物和磁铁矿组成。本文研究认为,硅酸盐矿物与磁铁矿在背散射电子图像中表现为熔离特征,这种在透光显微镜下呈黑色不透明的微晶固体,是引发交代蚀变、具熔浆流体特点和超临界流体性质的地幔流体交代作用的一种微观表现。     

Three-dimensional mapping of salt stores in the Murray-Darling Basin,Australia: 2. Calculating landscape salt loads from airborne electromagnetic and laboratory data

Salt is widespread in the Australian landscape – in soil, regolith and groundwater – leading to concerns that land management practices may be putting much agricultural land and important water resources at risk of salinisation. Defining the location and nature of salt stores is an important first step in understanding the processes leading to salinity of soils, streams and groundwater resources, and predicting areas that may be at risk. Airborne geophysics can define subsurface salt stores and mobilisation pathways. Airborne electromagnetics (AEM) can map the three-dimensional conductivity structure of the landscape but does not, intrinsically, quantify the amount of salt. Salinity, moisture content, porosity and mineralogy all contribute to the electromagnetic signal, and each can vary significantly throughout the landscape.In the Lower Balonne catchment, Queensland, the relationship between AEM and the amount of salt in the landscape was quantified using laboratory analyses of pore fluids from core samples. A general statistical relationship was established between AEM conductivity and salt load (defined as the product of pore fluid salinity, porosity and moisture content)—with a significant positive correlation although data were generally widely dispersed. Comparison of calculated salt load with borehole electromagnetic logs gives insight into the factors contributing to dispersion in the AEM data.The relationship transforms bulk conductivity to salt load in 5 m layers, allowing the generation of a three-dimensional map of the salt load. This is a powerful tool for identifying areas that may require monitoring and management interventions to reduce salinity risk. An example is given of salt loads beneath an established irrigation area in the Lower Balonne catchment, Queensland.     

胶西北金成矿区He、Ar同位素组成及成矿流体来源研究

胶东半岛西北地区是我国重要的金成矿区,主要受三山岛断裂、焦家断裂、招平断裂带控制。为探讨3条主要成矿带成矿流体的来源与区别,对成矿带内典型矿床载金黄铁矿中流体包裹体进行了He、Ar同位素测试。结合前人数据表明三山岛成矿带3He/4He均值为1.95 Ra,焦家成矿带^3He/^4He均值为1.74 Ra,招平成矿带^3He/^4He均值为1.54 Ra,从西往东逐渐降低,说明地幔流体参与成矿自西往东逐渐降低。黄铁矿流体包裹体中放射性成因Ar所占比例范围三山岛成矿带1.17%~87.12%,平均33.04%,焦家成矿带15.57%~90.00%,平均55.75%,招平成矿带7.94%~92.69%,平均44.23%,说明在成矿过程中,地壳成矿流体参与成矿作用焦家成矿带最高,招平成矿带次之,三山岛成矿带最低。结合H、O稳定同位素研究,认为成矿流体主要来源于地壳,并有地幔流体加入,具地壳流体和地幔流体混合特征,上升过程中可能还有少量大气降水的参与。     

高温高压下水的剪切粘滞度的平衡分子动力学计算

本项工作用ＴＩＰ４Ｐ模型对水分子进行了平衡分子动力学模拟。根据Ｇｒｅｅｎ－Ｋｕｂｏ理论,计算了温度从６５２Ｋ到８１４Ｋ,密度从０．５３６０ｇ／ｃｍ３到０．８６３８ｇ／ｃｍ３六个不同温度和密度水的剪切粘滞度,并和实验值进行了对比。在所计算的温度和密度范围,平衡分子动力学计算结果与实验值的平均绝对值差别为１５％,好于使用非平衡分子动力学方法获得的粘滞度值。平衡分子动力学的方法将是获得地学中高温高压下流体输运性质的重要途径。     

滇-黔-桂微细浸染型金矿床时空分布与成矿流体来源研究

滇-黔-桂微细浸染型金成矿带处于滇-黔-桂裂谷中。金矿床分布与深大断裂存在依附性。金矿带基本展布于深大断裂限定的三角区内,金矿床则分布于深大断裂旁侧或其交叉部位。由幔源岩浆岩(超基性岩及玄武岩)和幔源矿物沿深大断裂分布可推断,深大断裂延伸较深,可达上地幔,属超壳深大断裂。金矿床分布不受地层层位的限制,金矿化具有多层位成矿性。铅、硫、碳、氢、氧同位素地球化学综合对比研究表明,成矿热液中的矿质、矿化剂和水具深源与浅源的混合特征。热液成矿期矿石中石英及萤石的电子自旋共振(ESR)定年结果为68.40±32.41Ma,表明本区金矿床的成矿可能发生在燕山晚期-喜山早期。     

New Experimental Platform for Studies of Turbulence and Turbulent Mixing in Accelerating and Rotating Fluids at High Reynolds Numbers

We present a new experimental platform for studies of turbulence and turbulent mixing in accelerating and rotating fluids. The technology is based on the ultra-high performance optical holographic digital data storage. The state-of-the-art electro-mechanical, electronic, and laser components allow for realization of turbulent flows with high Reynolds number (>10⁷) in a relatively small form-factor, and quantification of their properties with extremely high spatio-temporal resolutions and high data acquisition rates. The technology can be applied for investigation of a large variety of hydrodynamic problems including the fundamental properties of non-Kolmogorov turbulence and turbulent mixing in accelerating, rotating and multiphase flows, magneto-hydrodynamics, and laboratory astrophysics. Unique experimental and metrological capabilities enable the studies of spatial and temporal properties of the transports of momentum, angular momentum, and energy and the identification of scalings, invariants, and statistical properties of these complex turbulent flows.     

滇西马厂箐铜钼多金属矿床成矿流体来源及演化过程——来自石榴子石原位微量元素及H- O同位素组成的限定

滇西马厂箐铜钼多金属矿床位于三江特提斯成矿域,是一个与喜马拉雅期富碱斑岩侵入有关的多金属矿床。前人研究表明,马厂箐铜钼多金属矿床形成于斑岩-矽卡岩成矿系统,但由于缺乏系统矿物学研究,目前对矽卡岩矿化过程和成矿效应仍不清楚,限制了对该矿床成矿过程的全面认识。因此,本文以马厂箐矿床矽卡岩型矿化中的石榴子石为研究对象,利用H-O同位素、电子探针(EPMA)以及LA-ICP-MS原位微区技术开展了同位素及成分分析,限定成矿流体来源以及反演成矿流体演化过程。石榴子石可分为早期自形石榴子石(Grt I)和晚期他形石榴子石(Grt II)。Grt I与辉石共生,并伴有黄铁矿、黄铜矿等金属矿物组合,属于钙铝-钙铁榴石固溶体(And_{49.37～99.58}Gro_0～49.79);Grt II更富Fe,属钙铁榴石系列(And_{67.50～99.85}Gro_0～31.84)。两期石榴子石均富含Th、U、Nd,亏损Ba、Sr、Hf、Nb,富轻稀土。基于石榴子石矿物化学特征认为,Grt I可能是在弱酸性、氧化、低水岩比(W/R)条...     

松辽盆地白垩系火山岩储层岩石物理声学特性分析

采集松辽盆地徐家围子地区9口探井57块营城组火山岩石样品,在模拟实际地层温度、压力条件下进行岩石物理参数测试,以期逐步实现火山岩储层流体的地球物理直接识别。采用超声脉冲透射法测定岩样的声学参数(纵波速度和横波速度),进行了不同流体状态下岩样的岩石物理参数特征分析。结果表明,在双参数域空间,特别是在体性-剪性双参数空间,火山岩含气储层与含水储层较易区分。     

粤北302铀矿床同位素地球化学研究

位于粤北诸广山岩体东南部的302铀矿床是我国规模较大、埋藏较深的花岗岩型铀矿床之一。该矿床产于印支期油洞岩体和燕山早期长江岩体的断裂蚀变带内,矿区内NWW向基性岩脉十分发育,矿体呈似脉状、扁豆状或透镜状。同位素研究表明,矿石的沥青铀矿Sm-Nd和U-Pb等时线年龄（70 Ma）与油洞岩体（232 Ma）、长江岩体（160 Ma）的年龄相差巨大;主成矿期成矿流体的δDH2O值为-65‰～-82‰（平均为-75‰）,δ18OH2O值为6.8‰～0.6‰（平均为3.9‰）,反映出成矿流体主要由地幔流体组成;方解石的δ13C值为-8.4‰～-5.3‰,表明矿化剂ΣCO2也来自地幔;矿区内辉绿岩的（87Sr/86Sr）i值为0.70861～0.70882,花岗岩的（87Sr/86Sr）i值为0.73519～0.77152,萤石的（87Sr/86Sr）i值为0.71474～0.71697,表明成矿组分Sr可能来源于基性脉岩（幔源）与赋矿花岗岩体（壳源）,并呈不同程度的混合,而主成矿组分铀主要来源于赋矿花岗岩体。     

Calcium,Na, K and Mg Concentrations in Seawater by Inductively Coupled Plasma‐Atomic Emission Spectrometry: Applications to IAPSO Seawater Reference Material,Hydrothermal Fluids and Synthetic Seawater Solutions

We report a measurement procedure to determine simultaneously the major cation concentrations (Na, Ca, K and Mg) of seawater‐derived solutions by inductively coupled plasma‐atomic emission spectrometry. The best results were obtained when the IAPSO (‘standard’) seawater reference material was diluted by thirty times with Milli‐Q^® water. We obtained an average reference value r_K (the ratio of the mass fraction of potassium to that of chlorine, i.e., (g kg^?1)/(g kg^?1)) for IAPSO seawater of 0.0205 ± 0.0006 (2.9% RSD), not significantly different from 0.0206 ± 0.0005 (2.4% RSD) for seawater composition reported in the literature. The measured Na, Ca and Mg concentrations correspond to r_Na, r_Ca and r_Mg values of 0.5406 ± 0.0026 (0.5% RSD), 0.02192 ± 0.00048 (2.2% RSD) and 0.06830 ± 0.00047 (0.7% RSD), respectively, in line with previous values measured by wet‐chemistry and atomic absorption spectrophotometry or wet‐chemical titration. Our measurement procedure was used successfully on synthetic seawater solutions and high‐temperature hydrothermal fluids.