The Glueckstadt Graben of the North-German Basin: new insights into the structure from 3D and 2D gravity analyses   总被引：1，自引：0，他引：1  

Tamara Yegorova  Yuriy Maystrenko  Ulf Bayer  Magdalena Scheck-Wenderoth 《International Journal of Earth Sciences》2008,97(5):915-930

The structure of the Glueckstadt Graben has been investigated by use of 3D gravity backstripping technique and by 2D gravity and magnetic modelling. Subtracting the gravity effects of the Meso-Cenozoic sediments together with Permian salt reveals a positive residual anomaly within the Glueckstadt Graben. This anomaly includes two local maxima over the Westholstein and Eastholstein Troughs. The 2D gravity models point to the presence of a high-density body within the lower crust of the Glueckstadt Graben. In addition, the results of 2D magnetic modelling indicate that the central part of the high-density body is overlain by an area with high susceptibility. Most probable, the formation of this high-density body is a result of complex poly-phase tectonic history of the study area. Finally, the results of gravity modelling indicate that Permian salt is not homogeneous. 3D gravity analysis and, especially, 2D gravity modelling have distinguished the differences in degree of salt saturation in salt-rich bodies, and elucidate the proportion of Rotliegend salt.  相似文献   

Comparison of numerical models of two debris flows in the Cortina d’ Ampezzo area,Dolomites, Italy   总被引：2，自引：0，他引：2  

Maria Concetta Armento  Rinaldo Genevois  Pia Rosella Tecca 《Landslides》2008,5(1):143-150

The accurate prediction of runout distances, velocities and the knowledge of flow rheology can reduce the casualties and property damage produced by debris flows, providing a means to delineate hazard areas, to estimate hazard intensities for input into risk studies and to provide parameters for the design of protective measures. The application of most of models that describe the propagation and deposition of debris flow requires detailed topography, rheological and hydrological data that are not always available for the debris-flow hazard delineation and estimation. In the Cortina d’Ampezzo area, Eastern Dolomites, Italy, most of the slope instabilities are represented by debris flows; 325 debris-flow prone watersheds have been mapped in the geomorphological hazard map of this area. We compared the results of simulations of two well-documented debris flows in the Cortina d’Ampezzo area, carried on with two different single-phase, non-Newtonian models, the one-dimensional DAN-W and the two-dimensional FLO-2D, to test the possibility to simulate the dynamic behaviour of a debris flow with a model using a limited range of input parameters. FLO-2D model creates a more accurate representation of the hazard area in terms of flooded area, but the results in terms of runout distances and deposits thickness are similar to DAN-W results. Using DAN-W, the most appropriate rheology to describe the debris-flow behaviour is the Voellmy model. When detailed topographical, rheological and hydrological data are not available, DAN-W, which requires less detailed data, is a valuable tool to predict debris-flow hazard. Parameters obtained through back-analysis with both models can be applied to predict hazard in other areas characterized by similar geology, morphology and climate.  相似文献   

Probabilistic modeling of seismically triggered landslides using Monte Carlo simulations     

Huabin Wang  Gonghui Wang  Fawu Wang  Kyoji Sassa  Yuping Chen 《Landslides》2008,5(4):387-395

The 2004 Chuetsu earthquakes of Niigata (Japan) triggered numerous landslides, and the most widespread types of landslides were highly disrupted, relatively shallow slides and soil (debris) flows. This paper presented a method to evaluate slope instability using Newmark displacement on a pixel-by-pixel basis in a given area. The proposed method was able to integrate Newmark displacement modeling and Monte Carlo simulations within geographical information systems. In the modeling, an empirical attenuation relationship was utilized to calculate Arias intensity over this study area, and the variability of geotechnical parameters was taken into account to calculate coseismic landslide displacement. Before deriving the displacement from related inputs, the Monte Carlo simulations ran 1,500 times and generated 1,500 displacement values for each grid cell, and then means and standard deviations of displacement were calculated and probabilistic distributions can be obtained. Finally, given 10 cm as a threshold value of displacement, estimated probabilities of displacement exceeding 10 cm were shown as a map of seismic landslide hazards. The resulting hazard map was classified into four categories from very low to high level.  相似文献   

基于改进Snake模型的道路网空间冲突处理     

吴小芳  杜清运  胡月明  徐智勇 《测绘学报》2008,37(2):0-249

在对Snake模型研究分析的基础上,结合地图制图的需求,从3个方面对Snake模型进行改进：首先建立Snake模型中参数与道路曲线形态特征的关系,以更好地保持移位前后道路形态的相似性;其次控制Snake模型中外力的传播范围,以尽量保持要素位置的准确性;最后,通过道路交叉点的权重属性控制,保证移位后各交叉点的连通性以及道路的整体拓扑关系不发生变化。在此基础上,提出道路网移位整体思路,并采用改进的Snake模型对其进行移位,解决空间冲突。  相似文献   

测井仪器的故障分析与排除思路     

邓红旗  陆勇 《中国煤炭地质》2008,(12):46-48

TYSC-3Q与PSJ-2型数字测井仪是目前煤田测井中常用的二种测井仪器,在使用过程中难免发生诸如测井控制故障、声速探管故障、密度三侧向探管故障、井温、井液电阻率探管故障、电法面板故障、数字测井面板故障、电测井故障等常见故障类型。通过对各类故障因素进行剖析,指出了故障易发生的部位,并详细的介绍了检查的方法及故障的排除步骤。  相似文献   

雁南煤矿北二采区充水因素及开采影响评价     

于世全  任德平 《中国煤炭地质》2008,20(3):51-52

在全面分析大雁矿业集团公司雁南煤矿北二采区的水文地质条件及煤层开采矿井充水因素的基础上,计算了开采27^1号煤层时导水裂隙带发育高度．得出了北二采区各煤层工作面开采即不会受到上部砂砾含水层的影响,雁南煤矿铁路涵洞以西的胜利河冲击沟也不会受到北二采区的采动塌陷影响的结论。  相似文献   

盘县马依东二井田构造特征及成因分析     

唐显贵 《中国煤炭地质》2008,20(4):7-10

利用井田勘探资料及野外地质资料,对井田构造基本形态、断层发育特征及其分布规律进行分析,总结出该井田的构造模式、构造成因、构造组合特征及其演化规律。研究认为井田的构造格局是多期构造运动综合作用、相互叠加的结果。井田构造形态为一略有起伏的平缓单斜,区内NE向的高角度正断层,多属张扭性,EW向构造早于NE向构造,构造复合部位较复杂,其余区段较简单;伸展构造是井田构造的主体样式,这一结论对下一步继续勘探及煤矿开采具有指导意义。  相似文献   

幔源CO_2释出机理、脱气模式及成藏机制研究进展   总被引：10，自引：0，他引：10  

鲁雪松  宋岩  柳少波  洪峰  付晓飞 《地学前缘》2008,15(6):293

针对幔源CO2如何从地幔岩浆中脱出并进入沉积地层中形成CO2气藏聚集这一关键问题,总结了国内外研究进展和前缘方向。研究表明,地幔深部的碱性玄武岩浆和碱性岩浆才是深部流体和CO2等挥发份大量赋存、渗滤和释出的场所。浅成侵入岩、次火山岩和火山通道等是CO2释放和聚集的有利位置,岩浆期后和岩浆衰弱期的热液活动阶段是CO2大量释放和聚集的有利时期。幔源CO2进入沉积盆地中具有3种脱气模式,即沿岩石圈断裂直接脱气模式、热流底辟体脱气模式和壳内岩浆房-基底断裂组合脱气模式。CO2的固有物化性质决定其运移相态多样,具有运移和聚集过程同步的特征。只有在满足大量的化学消耗及地层水或原油的溶解和耗散之后才能形成CO2有效聚集。幔源CO2成藏和分布主要受岩浆气源体和气源断裂体系的控制。今后,在超临界CO2及其对油气运移聚集的作用、CO2与深大断裂及火山岩的关系、CO2脱气运移机制、CO与常规烃类油气的耦合差异成藏机制等方面仍需要进一步的研究和探索。  相似文献   

塔河油田2区三叠系油藏类型初步探讨     

康立功 《安徽地质》2008,18(1):20-26

塔河油田2区三叠系油藏是西北分公司开发较早的碎屑岩油藏之一,开发层系有上油组、中油组,油柱高度在15～20m,储层为辫状三角洲相辫状三角洲前缘亚相水下分流河道、河口坝、分流间湾微相沉积,非均质性严重。本区上油组砂体厚度40～0m,中油组25～35m,分布较稳定,物性为中孔、中高渗储层,原油属低粘度轻质油。但2区三叠系油藏实钻变化大,见水快、产量递减快、含水上升快、采出程度低,开发效果较差,经过多次调整虽有一定程度改善,仍存在一些问题。本文认为2区三叠系油藏开发效果较差的原因之一是对本区油藏类型的认识上存在问题即2区三叠系油藏是以断裂控制的断块油藏而非背斜油藏,并延伸分析正在投入开发评价的S96-T901井区、TK232-T453井区及T206-T208井区等都为断块（断背斜）油藏。应用断块油藏的观点对塔河地区三叠系油藏勘探开发有重要指导意义。  相似文献   

有限元法模拟开挖引起的基坑水平位移和邻近建筑物沉降   总被引：1，自引：1，他引：0  

王晓  韦俊山  李巨龙  翟守俊 《上海国土资源》2008,(1):29-31,52

以徐州某采用水泥土墙支护的基坑为例,采用有限元数值模拟的方法,对基坑开挖引起的水平位移量和邻近建筑物沉降量进行了计算,并与实际监测值进行了对比分析,得到了一些关于如何控制基坑水平位移和减少基坑周边建筑沉降的结论。  相似文献