塔里木北部地区三叠系储层溶蚀作用机理

塔里木北部地区三叠系储层在成岩演化过程中曾经历两期溶蚀作用，深埋成岩环境的晚期溶蚀较早期近地表－浅埋成岩环境溶蚀要剧烈得多，溶蚀作用的最大特点是铝硅酸盐矿物较碳酸盐矿物剧烈。溶蚀作用发生的机理是由于三叠系储层处于８０～１２０℃热窗、成岩流体富含低分子量羧酸、碱度由低分子量羧酸控制，铝硅酸盐和碳酸盐矿物均处于去稳定状态。溶蚀作用的发育程度受控于储层砂体的沉积和岩石学特征以及早期成岩发育程度。     

Cracking mechanisms during galena mineralization in a sandstone-hosted lead–zinc ore deposit: case study of the Jinding giant sulfide deposit, Yunnan, SW China

There are two types of lead–zinc ore bodies, i.e., sandstone-hosted ores (SHO) and limestone-hosted ores (LHO), in the Jinding giant sulfide deposit, Yunnan, SW China. Structural analysis suggests that thrust faults and dome structures are the major structural elements controlling lead–zinc mineralization. The two types of ore bodies are preserved in two thrust sheets in a three-layered structural profile in the framework of the Jinding dome structure. The SHO forms the cap of the dome and LHO bodies are concentrated beneath the SHO cap in the central part of the dome. Quartz, feldspar and calcite, and sphalerite, pyrite, and galena are the dominant mineral components in the sandstone-hosted lead–zinc ores. Quartz and feldspar occur as detrital clasts and are cemented by diagenetic calcite and epigenetic sulfides. The sulfide paragenetic sequence during SHO mineralization is from early pyrite to galena and late sphalerite. Galena occurs mostly in two types of cracks, i.e., crescent-style grain boundary cracks along quartz–pyrite, or rarely along pyrite–pyrite boundaries, and intragranular radial cracks in early pyrite grains surrounding quartz clasts. The radial cracks are more or less perpendicular to the quartz–pyrite grain boundaries and do not show any overall (whole rock) orientation pattern. Their distribution, morphological characteristics, and geometrical relationships with quartz and pyrite grains suggest the predominant role of grain-scale cracking. Thermal expansion cracking is one of the most important mechanisms for the generation of open spaces during galena mineralization. Cracking due to heating or cooling by infiltrating fluids resulted from upwelling fluid phases through fluid passes connecting the SHO and LHO bodies, provided significant spaces for crystallization of galena. The differences in coefficients of thermal expansion between pyrite and quartz led to a difference in volume changes between quartz grains and pyrite grains surrounding them and contributed to cracking of the pyrite grains when temperature changed. Combined thermal expansion and elastic mismatch due to heating and subsequent cooling resulted in the radial and crescent cracking in the pyrite grains and along the quartz–pyrite grain boundaries.     

基于地基GPS-TEC的中国区域地震电离层效应研究

基于中国陆态网络地基GPS-TEC观测,针对2008～2019年发生在中国区域的7个M_S≥6.0地震,采用滑动四分位距法分析了地震前后的电离层扰动时空分布特征。结果显示,5个地震的震前2～6天,GPS-TEC值出现负异常扰动,地震发生期间及震后电离层TEC出现正异常扰动,主要集中在震后2～7天;GPS观测站距离震中越近,垂直上空的TEC扰动越明显,扰动空间最大范围可达2000km。随着震级的增加,震前电离层TEC异常扰动的发生率有所增加,且异常覆盖的范围也有所扩大。因此,认为震前一周内的电离层TEC变化可能提供揭示电离层扰动与地震活动之间关系的线索。     

用T/P测高数据反演海域重力异常

以反解 Stokes公式为数学模型 ,应用由 T/ P测高数据计算的大地水准面高反演了海域平均重力异常 ,并与船测平均重力异常和 OSU91A位模型计算的平均重力异常进行了比对分析 ,得出了一些有益的结论。     

空间直角坐标和大地坐标的转换

目前国内在空间直角坐标和大地坐标转换公式使用问题上 ,还明显缺乏必要的统一性。针对这个问题 ,本文作者在全面分析和比较国内外现有各种转换方法的基础上 ,重点推荐和介绍根据 Bowring研究思路导出的转换公式 ,这组公式既简单又具有很高的计算精度 ,能够满足各个部门的使用要求     

数字地图图像的基本形态学变换和结构元素的分解

本文是作者关于“数学形态学与数字地图图像的分析和识别”研究成果的一部分。文章提出了地图图形的集合概念和地图图像形态分析的基元确定原则,证明了结构元素的基元最小分解定理;同时,介绍了基本的形态学变换,统一并扩展了带约束条件的数学形态学变换模型;从而,奠定了数字地图图像分析和识别的数学基础。     

A strip adjustment procedure to mitigate the impact of inaccurate mounting parameters in parallel lidar strips

Lidar (laser scanning) technology has been proven as a prominent technique for the acquisition of high-density and accurate topographic information. Because of systematic errors in the lidar measurements (drifts in the position and orientation information and biases in the mirror angles and ranges) and/or in the parameters relating the system components (mounting parameters), adjacent lidar strips may exhibit discrepancies. Although position and orientation drifts can have a more significant impact, these errors and their impact do not come as a surprise if the quality of the GPS/INS integration process is carefully examined. Therefore, the mounting errors are singled out in this work. The ideal solution for improving the compatibility of neighbouring strips in the presence of errors in the mounting parameters is the implementation of a rigorous calibration procedure. However, such a calibration requires the original observations, which may not be usually available. In this paper, a strip adjustment procedure to improve the compatibility between parallel lidar strips with moderate flight dynamics (for example, acquired by a fixed-wing aircraft) over an area with moderately varying elevation is proposed. The proposed method is similar to the photogrammetric block adjustment of independent models. Instead of point features, planar patches and linear features, which are represented by sets of non-conjugate points, are used for the strip adjustment. The feasibility and the performance of the proposed procedure together with its impact on subsequent activities are illustrated using experimental results from real data.     

Shear Alteration, Mass Transfer and Gold Mineralization: An Example from Jiaodong Ore Deposit Concentrating Area, Shandong, China

Since Ramsay and Graham (1970 ) system atically deliv-ered study results of ductile shear zone,the study on shearzone has been put forward rapidly and has obtained greatachievements.After the“gold- bearing shear zone” type ofmetallogenic model proposed by Bonnemaison(1986 ) ,lots ofstudies showed that large gold- bearing shear zone system,which underwent multi- stage and multi- level tectonic- m inerl-ization evolution,is a complex deformational metam orphic ge-ological body with different d…     

长江流域旱涝典型年大气水汽输送

利用我国125个探空站一日两次自地面至100hpa共11个层次上的观测资料,对长江流域典型夏涝年(1980年)和夏旱年(1985年)我国大气中水汽总输送场、涡动输送场及散度场进行了计算分析。结果表明:当水汽总输送场从西北、西南和东南三支气流携带的水汽交汇于长江流域,且整个水汽输送场稳定持久,则在水汽辐合带附近导致大量降水,形成洪涝;反之,当三支气流微弱不稳定,不能形成水汽辐合带条件,则形成干旱。涡动输送亦反映出类似的特征。稳定且强盛的西南气流水汽输送是形成降水的主要条件和原因。     

中国近海海面地形的计算与研究

介绍了海面地形的研究现状,并根据几何水准求得了中国近海的海平面倾斜及其精度.给出应用水文资料计算中国近海海面地形的公式及其计算结果.探讨了由球函数模型计算中国近海海面地形的理论和方法,并对不同方法进行了比较,得出了一些有益的结论.