韧性剪切变形对岩石地球化学行为的制约——以北阿尔金巴什考供韧性剪切带为例   总被引：6，自引：0，他引：6  

戚学祥李海兵  吴才来陈松永 《地质通报》2005,24(3):252-257

韧性剪切变形对岩石地球化学行为的制约一直是地质学家们探讨的课题。本文以构成北阿尔金红柳沟——拉配泉俯冲碰撞杂岩带与北阿尔金地块边界的巴什考供斜向逆冲型韧性剪切带为例，通过对韧性剪切带内花岗岩变形前后不同变形强度构造岩的地球化学组成进行对比，确定等比线斜率，探讨韧性变形对岩石体积和成分变异的影响。计算结果表明，在糜棱岩化过程中，糜棱岩化花岗岩体积亏损21％，花岗质糜棱岩体积亏损31％。质量平衡计算结果和等比线图表明，韧；陛剪切作用导致SiO2，流失量最大，A12O3、K2O及Ba、Rb、Sr等都有不同程度的丢失，显示出较强的活动性，MnO、P2O5、Sc位于等比线上或附近，表现出相对的稳定性。岩石中活动组分的变异是流体渗滤作用引起的，不活动组分的变异是体．积亏损造成的。  相似文献   

离散裂隙渗流方法与裂隙化渗透介质建模   总被引：4，自引：1，他引：4  

王明玉  陈劲松等 《地球科学》2002,27(1):90-96

流体渗流模拟的连续介质方法通常适用于多孔地质体，并不一定适用于裂隙岩体，由于裂隙分布及其特征与孔隙差异较大。若流体渗流主要受裂隙的控制，对于一定尺寸的裂隙岩体，多孔介质假设则较难刻划裂隙岩体的渗流特征。离散裂隙渗流方法不但可直接用于模拟裂隙岩体非均质性和各向异性等渗流特征，而且可用其确定所研究的裂隙岩体典型单元体及其水力传导（渗透）张量大小。主要讨论了以下问题：（1）饱和裂隙介质中一般的离散流体渗流模拟；（2）裂隙岩体中的REV（典型单元体）及其水力传导（渗透）张量的确定；（3）利用离散裂隙网络流体渗流模型研究裂隙方向几何参数对水力传导系数和REV的影响；（4）在二维和三维离散裂隙流体渗流模型中对区域大裂隙和局部小裂隙的处理方法。调查结果显示离散裂隙流体渗流数学模型可用来评价不同尺度上的裂隙岩体的水力特征，以及裂隙方向对裂隙化岩体的水力特征有着不可忽视的影响。同时，局部小裂隙、区域大裂隙应当区别对待，以便据其所起的作用及水力特征，建立裂隙化岩体相应的流体渗流模型。  相似文献   

Size Scaling of Cross Correlation Between Multiple Variables     

Oz  Bora  Deutsch  Clayton V. 《Natural Resources Research》2002,11(1):1-18

Reservoir models have large uncertainty because of spatial variability and limited sample data. The ultimate aim is to use simultaneously all available data sources to reduce uncertainty and provide reliable reservoir models for resource assessment and flow simulation. Seismic impedance or some other attribute provides a key source of data for reservoir modeling. These seismic data are at a coarser scale than the hard well data and it not an exact measurement of facies proportions or porosity. A requirement for data integration is the cross-covariance between the well and seismic data.The size-scaling behavior of the cross correlation for different measurement scales was nvestigated. The size-scaling relationship is derived theoretically and validated by numerical studies (including an example with real data). The limit properties of the cross-correlation coefficient when the averaging volume becomes large is shown. After some averaging volume, the volume-dependent cross-correlation coefficient reaches a limit value. This plateau value is controlled mainly by the large-scale behavior of the cross and direct variograms.The cross correlation can increase or decrease with volume support depending on the relative importance of long- and short-scale covariance structures. If the direct and cross variograms are proportional, there is no change in the cross correlation as the averaging volume changes. Our study shows that the volume-dependent cross-correlation coefficient is sensitive to the shape of the cross variogram and differences between the direct variograms of the well data and seismic data.  相似文献   

城市基准地价评估的容积率内涵及其修正系数的确定--以石家庄市为例   总被引：6，自引：1，他引：6  

葛京凤  黄志英  梁彦庆 《地理与地理信息科学》2003,19(3):98-100,108

基淮地价评估是当前城市地价评估的主要形式。容积率既反映了土地的利用状况，同时也是影响地价的主要因素之一。该文阐述了容积率内涵，分析容积率与地价、环境的关系，探讨合理容积率的确定，以石家庄市为例，探索容积率修正系数确定的正确途径，避免在容积率概念、修正系数等问题上产生混淆。  相似文献   

天山1号冰川厚度和冰下地形探测与冰储量分析   总被引：12，自引：0，他引：12       下载免费PDF全文

孙波  何茂兵  张鹏  焦克勤  温家洪  李院生 《极地研究》2003,14(1):35-44

通过对天山乌鲁木齐河源 1号冰川的雷达回波探测 ,清晰地揭示出冰川底部冰 /岩界面的位置及其起伏变化特征 ,显示出雷达波对山地冰川良好的穿透能力和对冰下地形的高分辨能力 ,冰川雷达测厚的误差小于 1 .2 %。研究结果显示 ,1号冰川东支冰川平均厚度为 5 8.77m ,西支冰川平均厚度为 44.84m ,冰体厚度最大值发育于冰川中部趋于主流线位置。冰川冰储量计算表明 ,东支冰储量为 0 .0 5 1 868km3,西支冰储量为 0 .0 2 0 2 1 0km3。表面和底部地形有明显差异 ,主要因冰川动力过程对基岩强烈的地貌作用所致 ,意味着冰床的起伏地形对冰川浅层冰体的运动过程影响不显著。  相似文献   

GPS-measured land subsidence in Ojiya City, Niigata Prefecture, Japan   总被引：1，自引：0，他引：1  

Hiroshi P. Sato  Kaoru Abe  Osamu Ootaki 《Engineering Geology》2003,67(3-4):379-390

Land subsidence caused by compression of clay layers in Ojiya City, Japan was measured by global positioning system (GPS) between 1 April 1996 and 31 December 1998.

Three baselines were selected in and around the city, and height difference on a WGS-84 ellipsoid was measured by GPS on each baseline. The ground at the GPS station in the city subsides and rebounds 7 cm every winter and spring, respectively. Measurement accuracy was 9.5 mm standard deviation. Ground water level was observed at a well near the GPS station. Regression analysis between total strain, calculated as ratio of the height difference displacement to the total thickness of the clay layers, and the layers' effective stress change with ground water level change gave good correlation. The slope of regression line 7.0×10⁻¹¹ m²/N was obtained as an average apparent coefficient of volume compressibility of the layers.  相似文献   

SHOULD BESTOW MORE PHYSICAL CONNOTATION ON GRAIN SIZE PARAMETER     

CHEN YingyanAssociate Professor  Institute of Mountain Hazards  Environment  Chinese Academy of Sciences  Chengdu  Sichuan    China 《国际泥沙研究》1997,(3)

1.INTRODUCnONSAn~sizeplaysanimpo~roleinmanyfields,SUChasinndmeDt-laden~ordebrisflow.TheStateofsedimentmovementwhateVertheyaresugunded.jUInpingorbed-loading,isoftencloselyrelatedtOtheirSizes.Thebodyor~forcesbornacaglainareOftendiredproponionedtotheabcorSq~sizeofthisgrain.Thereforesedimentsizeisanimpohalltindextoesedimentcharacteristics.Besides,depositsizeanditsdistributionimplysome~infonnationdepositingfonnationenvironmentandcauseing~hyandgeqlogy.Ina~on.thesizeanditsdistributionareeac…  相似文献   

中国硫的供求现状和展望   总被引：1，自引：0，他引：1  

范可正  林乐 《化工矿产地质》1996,18(4):317-324

从工业和农业两个方面供需现状分析，中国目前硫的供需基本平衡，且供略大于求。展望２０００年，中国硫的供求关系将出现缺口，需进一步开拓硫的潜在资源。从总体上看，目前中国土壤供硫情况尚好，但一些地区已开始出现缺硫和严重缺硫的状况，预测今后土壤缺硫状况将会加剧，希望各有关部门对此应给予充分注意  相似文献   

剪切带的流体－岩石相互作用   总被引：5，自引：1，他引：5  

钟增球 《地学前缘》1996,(4)

作为大陆岩石圈中的应变局部化带，剪切带中一般都渗透着大量流体。流体的来源与剪切带所处的构造背景、流变域和水文条件有关，而剪切带中流体的流动则受岩石的渗透率、孔隙度、孔隙性质、流体的扩散和渗透能力、环境的温压条件、应力或载荷的梯度等因素所制约。剪切带中流体的成分、通量及赋存状态或流动方式，直接影响着岩石的流变。由应变局部化及力学失稳所引起的化学不平衡和由流体与岩石的相互作用，使剪切带岩石的矿物成分和化学成分发生调整，其变异程度取决于原岩的性质、剪切的温压条件和流体的成分及通量等。由于流体的渗透流动和流体与岩石的相互作用使剪切带的体积有所变化，体积变化过程是一种自组织行为。较大的体积亏损，意味着剪切带中渗透过大量的流体，这对剪切带的流变行为、化学行为和成矿作用都有深刻的影响。  相似文献   

Size of a debris flow deposition: model experiment approach   总被引：5，自引：0，他引：5  

X. Liu 《Environmental Geology》1996,28(2):70-77

 The prediction of the dangerous extent of a debris flow deposition is of vital importance, but difficult to achieve. Precise prediction of the depositional boundary of a debris flow event is impossible, but the size of a debris flow deposition could provide some estimates of the area, length, width, and thickness of a debris flow deposition. Based on in situ depositional experiments performed on a debris flow creek just after debris flows, a rule of thumb expressed by a group of equations containing the multiple-variate nonlinear functions is proposed in this paper. The interrelationships between the size and the causation also are discussed, and some empirical formulae to calculate the causative parameters for different regions are presented. Received: 24 April 1995 · Accepted: 21 June 1995  相似文献