引潮力引起的地球引力场时空变化的理论研究

地球重力场的时空结构与分布特性无论在基础理论研究,还是在地理空间信息建设中都具有重要的意义。地球表面上的观测仪器检测到的只是某一个质点的重力变化(拉格朗日变化),但是理论研究却是基于欧拉引力和引力位场方程进行的。本文基于连续介质力学的基本理论,在改正了文献[5]的一处原则性错误之后,推导出了引力和引力位的Lagrange和Euler增量表达式。本文工作对于高精度地球重力场的时空变化的理论研究具有参考价值。     

北祁连山银灿铜矿矿床地质特征及成因

银灿铜矿地处于北祁连走廊南山北坡—冷龙岭岛弧带中,矿区出露一套具双峰式火山岩特征的火山沉积建造,矿体主要赋存在石英角斑岩中并存在明显分带,上部为铜矿体向下部变为锌矿体,矿石类型属黄铁矿型多金属矿石,成矿作用过程直接或间接与火山活动有关,是北祁连地区早古生代典型的海相火山岩型块状硫化物矿床。     

AutoCAD与ArcGIS数据转换研究与应用

结合珠海市空间数据自适应动态更新系统的建设实践,提出AutoCAD与ArcGIS空间数据转换技术路线。阐述了这一过程中数据标准建立、质量控制和数据转换等关键技术。在此基础上,编程实现AutoCAD与GIS空间数据的相互转换以及空间数据库中GIS数据与AutoCAD数据的直接转换。试验结果显示,AutoCAD空间数据在编码、规整、转换和质检等处理后,可生成符合标准的GIS数据。     

稀土元素对鲁西铜石、铜井、龙宝山杂岩体的同源性制约

20世纪80年代,在山东省平邑县发现归来庄大型金矿床,实现了鲁西黄金找矿的重大突破。此后,鲁西相继发现卓家庄、磨坊沟和龙宝山金矿。近年,又在沂南金矿的深部发现新的矿体,鲁西良好的金矿成矿前景引起了地质学界的广泛关注。目前,鲁西发现的金矿床主要分布在铜石、铜井和龙宝山等燕山期杂岩体的附近。这些岩体在成因上有什么关系值得研究。通过对上述岩体稀土元素的地球化学分析,每种岩体不同期次侵入的岩浆岩的稀土元素分布形式和3种岩体综合稀土元素分布形式均呈向右陡倾的弧形线,且配分曲线形态基本相似,都没有明显的Ce、Eu异常,指示了岩体之间存在同源性,均来自深部同一岩浆房。该认识对于指导鲁西黄金找矿具有一定的意义。     

黄土高原半干旱区异常能量闭合率特征分析

以兰州大学半干旱气候与环境观测站（简称SACOL站）4 a的陆面通量数据为基础,利用普通最小二乘法（OLS）和能量平衡比率（EBR）方法,对能量平衡的异常闭合特征及其与相对垂直湍强（RIw）的关系进行了研究,并进行了能量滞后分析。结果表明,能量过闭合和负闭合现象分别主要发生在白天和夜间,大小遵从正态分布;较大异常闭合产生的原因主要是日出日落时净辐射与地表热通量接近以及降水影响造成湍流通量出现异常大值。一般来说,垂直湍流运动越强,异常闭合越少,闭合度越向1收敛,反之亦然。强湍流或极弱湍流都不利于产生异常闭合,过闭合、负闭合的最适相对垂直湍强RIw约为0.11、0.14。另外,能量支出项的相对滞后也是造成包括负闭合在内的异常闭合的原因之一。剔除湍强较弱的点或将地表热通量G0、感热H、潜热LE相位相对净辐射Rn提前30 min后,异常闭合所占比重减少;月平均EBR法过闭合度降低,OLS法闭合度提高。     

基于GoogleSketchUp的3DGIS建模技术研究与应用

分析了GIS三维模型的特点,阐述了GIS三维建模原理及流程,在VisualC#．Net平台下,利用GoogleSketchUp实现了三维场景的可视化和查询功能。     

Synchronous structure control of superlarge ore deposits

The control of synchronous structures on formation of superlarge stratabound ore deposits is immense. Based on studies of ore deposits in South Qiniing, northern Guangdong, Langshan and other areas, three new ideas in comparison with examples of ore control of synchronous structures both in China and abroad are proposed: (i) multiorder ore control of synchronous structures, which means that synchronous structures of different orders display different controls on ore deposits; (ii) synchronous structures in different stages of basin evolution display different controls on basin fluid system and ore-forming system; (iii) synchronous strurture accompanying hydrothermal mineralization as a preexisting weak surface in earth crust often reactivate in later tcctono-thermal event to be a channelway for magma or thermal fluids which superimposed on and reformed preexisting ore beds to form large or superlarge composite ore deposits.     

基于MODIS反演祁连山七一冰川雪粒径

基于MODIS 500 m分辨率数据,利用MODTRAN 4+模型和可见光波段、近红外波段的波段比方法反演雪粒径,建立1个消融期内的雪粒径变化的时间序列,通过采集七一冰川上设立的观测点对应时间段内雪粒径验证MODIS模拟的雪粒径值,结合位于观测点附近的气象站的气温数据,探讨气温对雪粒径的影响。结果表明,雪粒径的增长存在着明显的日变化趋势;模拟的雪粒径普遍高于实测的雪粒径值,因此反演模型需要约为1.1倍的校正因子;气温对雪粒径的影响显著。     

Petrogenetic and Metallogenetic Background of the Dajing Cu–Sn–Ag–Pb–Zn Ore Deposit, Inner Mongolia, and Characteristics of the Mineralizing Fluid

Abstract: The Dajing Cu–Sn–Ag–Pb–Zn ore deposit, Inner Mongolia of China, is a fissure‐filling hydrothermal ore deposit that occurs within the Upper Permian Linxi group. No magmatic pluton and volcanic rocks outcrop on the surface of the deposit. Most of ore veins show clear‐cut boundary with country rocks. Wallrock alterations that include silicification, carbonation, chlori–tization, and sericitization are generally weak and occur in the close vicinity of ore veins. Mineralization is divided into three stages: (1) cassiterite–arsenopyrite–quartz stage, (2) sulfide stage, and (3) Pb–Zn–Ag–carbonate stage. These mineralization stages have distinct ranges of homogenization temperatures, 290–350C for Stage 1, 260–320C for Stage 2, and 150–250C for Stage 3. However, salinities for Stages 1, 2, and 3 overlap and range between 2.2 and 10.4 wt % NaCl equivalent. The dD values relative to V‐SMOW of inclusion water from quartz are lower than –88% and centered at –100 to –130%. The δ³⁴S values relative to CDT of sulfide ore minerals and δ¹³C values relative to PDB of carbonate gangue minerals, vary from –0.3 to +2.6%, and from –7.0 to –2.9%, respectively. Integrated isotopic data point to two major contributions to the mineralizing fluid that include a dominant meteoric‐derived water and the other from hypogene magma for sulfur and carbon species. Analyses of inclusion gas and liquid compositions are performed. The H₂O and CO₂ are the two most abundant gaseous components, whereas SO₄^2‐ and Cl^‐, and Na⁺, Ca²⁺, and K⁺ are the major anions and cations, respectively. A linear trend is shown on the gaseous H₂O versus CO₂ plot. Phase separation is excluded as cause for the trend on the basis of isotope data and fluid inclusion microthermometry. In addition, a weak wallrock alteration does not support fluid‐rock interaction as an efficient mechanism. Hence, the linear H₂O–CO₂ trend is interpreted in terms of absorption or dilution of CO₂–dominant magmatic vapor by meteoric‐derived water. Cooling effects resulting from dilution may have caused precipitation of ore minerals. Major and trace element compositions of regional granites show a high‐K calc–alkaline characteristics and an arc–affinity. Lead isotopic compositions of galena samples from the Dajing deposit exhibit elevated U/Pb and Th/Pb ratios. These characteristics indicate a common source of supra subduction zone mantle wedge for regional granites and metals from the Dajing deposit.     

绘图方式对直流电测深等值线断面图的影响

以一条测线的直流电测深资料为例,分别用人工和Surfer软件绘制出视电阻率等值线断面图进行比较,从而说明:正确地应用Surfer软件绘制等值线图非常重要,关键是网格化前对x、y值的表达方式以及选择那种插值方法,如何插值才能取得理想的效果,否则会直接影响资料解释,甚至会得出错误的结论。