伸展地区铲式正断层作用及其大地测量观测   总被引：1，自引：1，他引：1  

桂Kun长 《地质论评》1993,39(3):196-204

铲式正断层作用是伸展构造区最主要的构造运动形式。本文根据铲式正断层作用的几何学、运动学特征,结合华北平原伸展区大地测量观测成果,探讨伸展区构造形变铲式正断层现今活动的地表形变效应及其动态特征。  相似文献   

采用阶梯抽水试验资料确定含水层参数     

王必刚 《上海国土资源》1993,(3):27-36

本文采用阶梯降深的有关公式,结合某矿区的一次多孔抽水试验资料进行试算,并和雅柯布直线法和恢复水位法求得的参数比较,汁算结果令人满意,表明该法是种简便、有效的求参手段。  相似文献   

青藏块体及其周边地震活动   总被引：1，自引：0，他引：1  

赵振才 《高原地震》1993,(2)

本文从青藏块体及其周边地区地震活动幕的划分入手,分析各期地震活动的图象特征,寻求本区地震发生的时空规律,探讨本区的地震活动与印度板块运动的内在联系,从而对今后本区地震活动的大形势进行了预测。  相似文献   

国家地震局地震工程代表团赴美访问     

The Earthquake Engineering Delegation of SSB 《国际地震动态》1993,(3):12-16

  相似文献   

PROGRAM FOR PROCESSING OF HISTORICAL LABORATORY DATA BASED ON FUZZY SET THEORY AS A TOOL FOR DECISION SUPPORT     

J.KLAESSENS  J.VANSCHALKWIJK  P.COX  R.BEZEMER  B.VANDEGINSTE  G.KATEMAN 《地理学报(英文版)》1988,(1)

A computer program(FEA)is presented for processing historical laboratory data.It performs on a list ofsample entries stored in a laboratory information management system.Using an algorithm which is basedon fuzzy set theory,FEA classifies the entries into a limited number of clusters called sample types.Theclassification is fully user-defined.The program transforms the historical data into a representation whichis more suitable for studying the performance of the laboratory or which can be used as preparation for asimulation project.  相似文献   

Monte Carlo Radiative Transfer Modeling of Lightning Observed in Galileo Images of Jupiter   总被引：1，自引：0，他引：1  

U.A. DyudinaA.P. Ingersoll  A.R. VasavadaS.P. Ewald  the Galileo SSI Team 《Icarus》2002,160(2):336-349

We study lightning on Jupiter and the clouds illuminated by the lightning using images taken by the Galileo orbiter. The Galileo images have a resolution of ∼25 km/pixel and are able to resolve the shape of single lightning spots, which have half widths (radii) at half the maximum intensity in the range 45-80 km. We compare the shape and width of lightning flashes in the images with simulated flashes produced by our 3D Monte Carlo light-scattering model.The model calculates Monte Carlo scattering of photons in a 3D opacity distribution. During each scattering event, light is partially absorbed. The new direction of the photon after scattering is chosen according to a Henyey-Greenstein phase function. An image from each direction is produced by accumulating photons emerging from the cloud in a small range (bins) of emission angles. The light source is modeled either as a point or a vertical line.A plane-parallel cloud layer does not always fit the data. In some cases the cloud over the light source appears to resemble cumulus clouds on Earth. Lightning is estimated to occur at least as deep as the bottom of the expected water cloud. For the six flashes studied, we find that the clouds above the lightning are optically thick (τ>5). Jovian flashes are more regular and circular than the largest terrestrial flashes observed from space. On Jupiter there is nothing equivalent to the 30-40-km horizontal flashes that are seen on Earth.  相似文献   

Magnetic properties of soils from sites with different geological and environmental settings   总被引：7，自引：0，他引：7  

Hana Fialov  Günter Maier  Eduard Petrovský  Ale&#x; Kapi ka  Tetyana Boyko  Robert Scholger  MAGPROX Team 《Journal of Applied Geophysics》2006,59(4):273-283

Measurements of magnetic susceptibility of soils, reflecting magnetic enhancement of topsoils due to atmospherically deposited magnetic particles of industrial origin, are used recently in studies dealing with outlining polluted areas, as well as with approximate determination of soil contamination with heavy metals. One of the natural limitations of this method is magnetic enhancement of soils caused by weathering magnetically rich parent rock material. In this study we compare magnetic properties of soils from regions with different geological and environmental settings. Four areas in the Czech Republic and Austria were investigated, representing both magnetically rich and poor geology, as well as point-like and diffuse pollution sources. Topsoil and subsoil samples were investigated and the effect of geology and pollution was examined. Magnetic data including mass and volume magnetic susceptibility, frequency-dependent susceptibility, and main magnetic characteristics such as coercivity (Hc and Hcr) and magnetization (Ms and Mrs) parameters are compared with heavy metal contents. The aim of the paper is to assess the applicability of soil magnetometry under different geological-environmental conditions in terms of magnetic discrimination of dominant lithogenic/anthropogenic contributions to soil magnetic signature. Our results suggest that lithology represents the primary effect on soil magnetic properties. However, in case of significant atmospheric deposition of anthropogenic particles, this contribution can be clearly recognized, independent of the type of pollution source (point-like or diffuse), and discriminated from the lithogenic one. Different soil types apparently play no role. Possible effects of climate were not investigated in this study.  相似文献   

陕西凤县八方山-二里河（铜）铅锌矿床地质特征及成矿模式     

陈二虎张新胜  高卫宏 《西北地质》2007,40(B07):13-17

在综合分析凤-太矿集区成矿构造特征的基础上，依据以往总结的凤．太矿田铅锌、金矿聚矿构造模式，通过对八方山-二里河铅锌矿床地质特征的分析，总结了找矿标志，初步认为八方山-二里河（铜）铅锌矿床的成矿模式为：“前泥盆纪海底热水喷流沉积一印支-燕山期构造改造型”铅锌矿床。认为成矿物质来源于基底，后期的构造-岩浆改造使基底成矿元素活化，沿同生断裂迁移、改造，最后在泥盆系中形成的扩容性构造部位富集成矿。提出了下一步扩大找矿的方向和建议。  相似文献   

Evolution of the Mesozoic Granites in the Xiong''ershan-Waifangshan Region,Western Henan Province,China,and Its Tectonic Implications          下载免费PDF全文

Franco PIRAJNO 《《地质学报》英文版》2007,81(2)

Based on the new data of isotopic ages and geochemical analyses, three types of Mesozoic granites have been identified for the Xiong'ershan-Waifangshan region in western Henan Province: high-Ba-SrⅠ-type granite emplaced in the early stage (～160 Ma),Ⅰ-type granite in the middle stage (～130 Ma) and anorogenic A-type granite in the late stage (～115 Ma). Geochemical characteristics of the high-Ba-SrⅠ-type granite suggest that it may have been generated from the thickened lower crust by partial melting with primary residues of amphibole and garnet. Gradual increase of negative Eu anomaly and Sr content variations reflect progressive shallowing of the source regions of these granites from the early to late stage. New 40Ar/39Ar plateau ages of the early-stage Wuzhangshan granite (156.0±1.1 Ma, amphibole) and middle-stage Heyu granite (131.8±0.7 Ma, biotite) are indistinguishable from their SHRIMP U-Pb ages previous published, indicating a rapid uplift and erosion in this region. The representative anorogenic A-type granite, Taishanmiao pluton, was emplaced at～115 Ma. The evolution of the granites in this region reveals a tectonic regime change from post-collisional to anorogenic between～160 Ma and～115 Ma. The genesis of the early- and middle-stageⅠ-type granites could be linked to delamination of subducted lithosphere of the Qiniing orogenic belt, while the late-stage A-type granites represent the onset of extension and the end of orogenic process. In fact, along the Qiniing -Dabie-Sulu belt, the Mesozoic granitoids in western Henan, Dabieshan and Jiaodong regions are comparable on the basis of these temporal evolutionary stages and their initial 87Sr/86Sr ratios, which may suggest a similar geodynamic process related to the collision between the North China and Yangtze cratons.  相似文献   

苏北超基性岩某些超高压变质特征   总被引：10，自引：2，他引：8  

陆永增 《江苏地质》1998,22(1):1-9

苏北芝麻坊超基性岩体,位于大别—苏鲁超高压变质带东段的核心部位,与基性榴辉岩紧密伴生,是苏北最具代表性的岩体之一。根据多年来的成果资料,研究它的超高压变质特征,对研究整个苏鲁超高压变质带具有重大意义。对岩体的形态特征、岩相学特征、特别是矿物学特征,如镁铝榴石特征的研究,结合金刚石的选出,都有力的证实苏北超基性岩是在超高压变质环境下生成的,同时也反映其是由华北地块与扬子地块俯冲碰撞而从地壳深处挤压上来的幔源物质。  相似文献