海底浅地层声纳探测在断层精确定位中的应用          下载免费PDF全文

吴子泉  王志才  曹文海  王纪强  陶九庆  姜早峰 《地震工程学报》2006,28(4):331-334

根据沉积条件和覆盖层厚度,选用声纳探测方法对山东威海湾神道口断裂在海域内的走向及位置进行了海域探测,取得了较好的剖面资料。利用海域地形资料对结果进行了检验,证明了结果的有效性,从而实现了断裂在海域的精确定位。  相似文献   

唐山地震发震构造的浅层地震探测   总被引：8，自引：2，他引：6  

郝书检  李建华 《中国地震》1998,14(4):78-84

利用浅层地震探测方法,研究了唐山地震区１年前出现在卫星图像上的异常现象与发震构造的关系,探讨地震中长期预测的途径。结果表明：唐山地震断层是一条倾向ＮＷ的右旋走滑第四纪同生断裂,它错断了全新统,晚更新统,中更新统,和早更新统地层。  相似文献   

An overview of the geology of the Transvaal Supergroup dolomites (South Africa)   总被引：1，自引：0，他引：1  

P. G. Eriksson  W. Altermann 《Environmental Geology》1998,36(1-2):179-188

 In the Neoarchaean intracratonic basin of the Kaapvaal craton, between approximately 2640 Ma and 2516 Ma, two successive stromatolitic carbonate platforms developed. Deposition started with the Schmidtsdrif Subgroup, which is probably oldest in the southwestern part of the basin, and which contains stromatolitic carbonates, siliciclastic sediments and minor lava flows. Subsequently, the Nauga formation carbonates were deposited on peritidal flats located to the southwest and were drowned during a transgression of the Transvaal Supergroup epeiric sea, around 2550 Ma ago. This transgression led to the development of a carbonate platform in the areas of the preserved Transvaal and Griqualand West basins, which persisted for 30–50 Ma. During this time, shales were deposited over the Nauga Formation carbonates in the southwestern portion of the epeiric sea. A subsequent period of basin subsidence led to drowning of the stromatolitic platform and to sedimentation of chemical, iron-rich silica precipitates of the banded iron formations (BIF) over the entire basin. Carbonate precipitation in the Archaean was largely due to chemical and lesser biogenic processes, with stromatolites and ocean water composition playing an important role. The stromatolitic carbonates in the preserved Griqualand West and Transvaal basins are subdivided into several formations, based on the depositional facies, reflected by stromatolite morphology, and on intraformational unconformities; interbedded tuffs and available radiometric age data do not yet permit detailed correlation of units from the two basins. Thorough dolomitisation of most formations took place at different post-depositional stages, but mainly during early diagenesis. Partial silicification was the result of diagenetic and weathering processes. Karstification of the carbonate rocks was related to periods of exposure to subaerial conditions and to percolation of groundwater. Such periods occurred locally at the time of carbonate and BIF deposition. Main karstification, however, probably took place during an erosional period between approximately 2430 Ma and 2320 Ma. Received: 15 September 1996 · Accepted: 12 May 1998  相似文献   

Shallow landslide hazard assessment using a physically based model and digital elevation data   总被引：6，自引：1，他引：5  

M. Borga  G. Dalla Fontana  D. Da Ros  L. Marchi 《Environmental Geology》1998,35(2-3):81-88

 A model for the analysis of topographic influence on shallow landslide initiation is applied to an experimental mountain basin where high-resolution digital elevation data are available: the Cordon catchment (5 km²) located in northern Italy. The model delineates those areas most prone to shallow landsliding due to surface topographic effects on hydrologic response. The model is composed of two parts: a steady-state model for shallow sub-surface runoff and an infinite-slope Coulomb failure model which assumes that the soil is cohesionless at failure. An inventory of landslide scars is used to document sites of instability and to provide a test of model performance by comparing observed landslide locations with model predictions. The model reproduces the observed distribution of landslide locations in a consistent way, although spatial variations in soil strength and transmissivity, which are not accounted for in the model, influence specific distribution of landslide areas within regions of similar topographic control. Received: 15 October 1996 · Accepted: 25 June 1997  相似文献   

我国浅层生物气藏的压力特征及成因探讨     

任光明 《海相油气地质》1998,3(1):23-26

对中国迄今已发现的浅层生物气藏研究资料的分析统计,发现这类气藏的压力系数大多数介于０．９￣１．１之间,属于常压气藏。该类气藏具有时代新（主要分布在第三系和第四系中）、埋藏浅（３０￣１５００ｍ）、水文地质条件相对开启、地层成岩作用弱、孔隙度和渗透率高、盖层封闭能力差、沉积剖面中砂岩含量高、经受的地层温度低、气藏高度小等特点,这是由其地质条件决定的。生物气藏这种特征,可为钻控这类气藏时,配用适当密度的  相似文献   

淮北煤田下石盒子组七煤段沉积模式与聚煤特征   总被引：1，自引：0，他引：1  

胡宝林 《中国煤田地质》1996,8(2):23-25,74

煤田地质工作者发现，我国晚古生代煤系高建设性三角洲成煤作用尤为发育。采用地层垂直层序分析，砂体分析，岩矿及地化分析，测井曲线分析等方法，并编制了分析性图件，对本区七煤段进行剖析，认为该段是一套以浅水三角洲环境为主的沉积组成；同时，对其成煤特征进行了探讨。  相似文献   

浅层地温在滇西南地震预报中的应用     

尤传侠 《地震研究》1989,12(3):254-259

本文根据地表面幅射平衡和热量平衡的原理,对浅层地温进行了一些数学方法的处理;并用于滇西南的地震预报实践。作出了1984年4月24日孟连南6.1级地震和1986年5月8日普洱附近的M_L=5.2级地震的中、短期预报。  相似文献   

Shallow landslides in pyroclastic soils: a distributed modelling approach for hazard assessment   总被引：3，自引：0，他引：3  

Paolo Frattini  Giovanni B. Crosta  Nicoletta Fusi  Paolo Dal Negro 《Engineering Geology》2004,73(3-4):277-295

An effective assessment of shallow landslide hazard requires spatially distributed modelling of triggering processes. This is possible by using physically based models that allow us to simulate the transient hydrological and geotechnical processes responsible for slope instability. Some simplifications are needed to address the lack of data and the difficulty of calibration over complex terrain at the catchment's scale. We applied two simple hydrological models, coupled with the infinite slope stability analysis, to the May 1998 landslide event in Sarno, Southern Italy. A quasi-dynamic model (Barling et al., 1994) was used to model the contribution to instability of lateral flow by simulating the time-dependent formation of a groundwater table in response to rainfall. A diffusion model [Water Resour. Res. 36 (2000) 1897] was used to model the role of vertical flux by simulating groundwater pressures that develop in response to heavy rainstorms. The quasi-dynamic model overestimated the slope instability over the whole area (more than 16%) but was able to predict correctly slope instability within zero order basins where landslides occurred and developed into large debris flows. The diffusion model simulated correctly the triggering time of more than 70% of landslides within an unstable area amounting to 7.3% of the study area. These results support the hypothesis that both vertical and lateral fluxes were responsible for landslide triggering during the Sarno event, and confirm the utility of such models as tools for hazard planning and land management.  相似文献   

江西东乡铜矿成矿地质特征与找矿实践   总被引：3，自引：0，他引：3  

付守会  陈广浩 《大地构造与成矿学》2003,27(3):282-286

充分利用前人的研究成果,结合在赣东北地区的找矿实践,对东乡铜矿成矿条件、成矿特征等进行剖析,认为该矿为斑岩型铜矿,是赣东北斑岩铜矿带的一部分;矿区广泛分布的花岗闪长斑岩小岩体与深部隐伏斑岩体断续连接,是成矿物质和热能的主要来源。在此基础上开展了浅层地震找矿应用研究,为资源危机型矿山的地勘工作提供了一条新的思路和方法。  相似文献   

城市活断层的抗干扰高分辨率浅层地震勘探研究   总被引：11，自引：0，他引：11  

潘纪顺  张先康  刘保金  方盛明  王夫运  段永红  张红强 《中国地震》2003,19(2):148-157

首先，简要介绍了城市活断层探测的意义及世界各国开展城市活断层探测的基本情况。在简述抗干扰高分辨率浅层地震勘探基本原理的基础上，重点论述了城市活断层的抗干扰高分辨率浅层地震勘探的震源激发、数字地震仪性能、接收方式与接收条件、观测系统以及数据处理与资料解释等。研究表明，对于城市活断层的抗干扰高分辨率浅层地震勘探，在数据采集环节应采用具有线性或非线性变频扫描功能的可控震源和与其相匹配的地震仪器，以及小道间距、小偏移距、多接收道、短排列和高频检波器接收的工作方法；在数据处理与解释环节，要重视折射静校正技术、噪声压制技术、高精度速度分析技术、子波压缩技术、子波零相位化技术和叠前偏移技术等的应用。最后，给出了城市活断层的抗干扰高分辨率浅层地震勘探实例。  相似文献