金湖凹陷油气成藏动力学研究   总被引：3，自引：1，他引：3  

常象春  薛泽磊  刘玉瑞  张金亮 《矿物岩石地球化学通报》2003,22(4):319-323

成藏动力学系统是近几年在油气成藏研究中的一大热点，它以油气成藏的动力学机制和动力学过程为核心，探讨油气聚集和分布规律。本在总结前人研究成果基础上，将金湖凹陷划分为3个成藏动力学子系统和5种油气输导体系，并利用流体包裹体恢复了成藏流体充注时间；根据油气运移聚集特征，总结出“下生上储”和“自生自储”两种成藏模式；从成藏条件出发，探讨了油气成藏主控要素。  相似文献   

Quaternary folding of the eastern Tian Shan, northwest China   总被引：3，自引：0，他引：3  

Bihong Fu  Aiming Lin  Ken-ichi Kano  Tadashi Maruyama  Jianming Guo 《Tectonophysics》2003,369(1-2):79-101

The Tian Shan, east–west trending more than 2000 km, is one of most active intracontinental mountain building belts that resulted from India–Eurasia collision during Cenozoic. In this study, Quaternary folding related to intracontinental mountain building of the Tian Shan orogenic belt is documented based on geologic interpretation and analyses of the satellite remote sensing images [Landsat Thematic Mapper (TM)/Enhanced Thematic Mapper (ETM) and India Remote Sensing (IRS) Pan] combined with field geologic and geomorphic observations and seismic reflection profiles. Analyses of spatial–temporal features of Quaternary folded structure indicate that the early Quaternary folds are widely distributed in both piedmont and intermontane basins, whereas the late Quaternary active folds are mainly concentrated on the northern range-fronts. Field observations indicate that Quaternary folds are mainly characterized by fault-related folding. The formation and migration of Quaternary folding are likely related to decollement surfaces beneath the fold-and-fault zone as revealed by seismic reflection profiles. Moreover, analysis of growth strata indicates that the Quaternary folding began in late stage of early Pleistocene (2.1–1.2 Ma). Finally, tectonic evolution model of the Quaternary deformation in the Tian Shan is presented. This model shows that the Quaternary folding and faulting gradually migrate toward the range-fronts due to the continuous compression related to India–Eurasia collision during Quaternary time. As a result, the high topographic relief of the Tian Shan was formed.  相似文献   

Experimental evidence for the dynamics of the formation of the Yinggehai basin, NW South China Sea   总被引：1，自引：0，他引：1  

Zhen Sun  Di Zhou  Zhihong Zhong  Zuoxun Zeng  Shimin Wu 《Tectonophysics》2003,372(1-2):41-58

The Yinggehai basin is located on the northwestern shelf of the South China Sea. It is the seaward elongation of the Red River Fault Zone (RRFZ). The orientation and rift shape of the Yinggehai basin are mainly controlled by NW-, NNW- and nearly NS-trending basal faults. The depocenter migrated southeastward when the basin developed. The depocenter trended northwest before about 36 Ma, then jumped southward and became nearly N–S trending and migrated toward the southeast up to 21 Ma; thereafter, the depocenter trended northwest again. Based on above and structural evolution in neighbor areas, it is believed that the Yinggehai basin formation was mainly controlled by the extrusion accompanied by clockwise rotation of Indochina. We set up analogue models (thin basal plate model and thick basal plate model) to investigate the evolution of Yinggehai basin. From the experiments, we consider that the basin evolution was related to the extrusion and clockwise rotation of the Indochina block, which was caused by the collision of the Indian plate and Tibet. This process took place in four main stages: (1) Slow rifting stage (before 36 Ma) with a NW-trending depocenter; (2) rifting stage formed by sinistral slip of the Indochina block accompanied by rapid clockwise rotation between 36 and 21 Ma; (3) rifting-thermal subsidence stage affected by sinistral slip of the Indochina (21–5 Ma) block and (4) dextral strike–slip (5–0 Ma).  相似文献   

三峡水库沿岸移民区地质灾害防治研究   总被引：2，自引：1，他引：2  

刘广润  徐开祥 《中国地质灾害与防治学报》2003,14(4):1-4

长江三峡水利工程是举世无双的宏伟工程，其水库的百万移民大都采取就地后靠安置。水库沿岸地质条件较复杂，滑坡、崩塌众多，地质灾害对移民的安全有重大影响。国家对三峡水库沿岸移民区的地质灾害防治给予高度重视。从20世纪50年代开始就开展了库岸稳定性和地质灾害调查，对其中的几十处重大滑坡进行过勘探，并对有重大影响的鸡扒子滑坡、链子崖危岩体、黄腊石滑坡、豆芽棚滑坡等进行了有效的工程治理。最近又拨数十亿巨款进行现阶段的大规模地质灾害防治。根据此次防治前的全面调查，全库区共有滑坡崩塌灾害点2490处。其中涉及135m蓄水水位及2期移民新址安全的，纳入本期防治规划，计581处。依据滑坡崩塌的危险性，防治难度及危害对象的可迁移程度。采取不同防治对策。已进行工程治理的198处，搬迁避让的232处，加强监测预警的151处。防治工作有重大的社会、经济效益和较高的科学技术难度，现在正在紧张进行中。文中分段论述了库区地质灾害特征及以往防治研究历史，现阶段防治研究工作要点和今后防治研究的主要课题。  相似文献   

Kalligrammatid Lacewings from the Upper Jurassic Daohugou Formation in Inner Mongolia, China   总被引：3，自引：1，他引：3  

ZHANG JunfengNanjing Institute of Geology  Palaeontology  Chinese Academy of Sciences  Nanjing  Jiangsu  E-mail: jfzhang@nigpas.ac.cn 《《地质学报》英文版》2003,77(2):141-147

A new species, referable to a new genus, is erected, and named the Sinokalligramma jurassicum gen. et sp. nov. It is the second finding of kalligrammatids in the Daohugou Formation. The origin and migration of the family Kalligrammatidae are discussed. The geological age and stratigraphic correlation of the Daohugou and Karabastau Formations are briefly reviewed and reassessed.  相似文献   

Measurements of ^222Rn and ^220Rn with a Large Size Collector of Radon Progeny     

WuQifan JiaWenyi FangFang WangJun ChengJianping LiuGuilin ZhuLi 《中国地质大学学报(英文版)》2003,14(2):151-154

Radon concentrations in high background radiation areas in the south are higher than those of others in China, especially ^220Rn concentration is significantly high. Therefore, measurements of ^222Rn and ^220Rn concentrations should be carried out there. This paper introduces a large size collector of radon progeny and its applications. The collector is a sheet of polyvinyl chloride fiber with electrostatics of (-500 V)-(-700 V). Its size (60 mm in diameter) is larger than those of others (26 mm in diameter) that work with the same principle. The collector is more effective to adsorb radon progeny than most of others. The equipment of ZnS(Ag) Scintillation Counting System is available for large size collectors to detect radon progeny. Therefore, its sensitivity of measurement is higher than that of others. According to the different half lives of radon progeny, and based on both theory and experiments, a formula for discrimination and calculation of ^222Rn and ^220Rn concentrations is deduced. The ^222Rn and ^220Rn concentrations were surveyed with electrostatic collectors of radon progeny on the campus of commercial school and some other areas in Hainan, southern China. Neither ^222Rn nor ^220Rn concentration was found significantly high. However, several faults underground were delineated. The collector is also used to study radon transportation. Results indicate that radon changes regularly with date when it has transported for a certain distance. Velocities of radon migration in the four media are quite different. Radon migrates more quickly in vertical tube than in the horizontal tube.  相似文献   

弹性波逆时偏移及其成像条件   总被引：6，自引：0，他引：6  

田雪丰  张奋轩等 《中国煤田地质》2002,14(2):58-61

从弹性波动方程出发,推导了二维各向同性介质情况下弹性波逆时传播的高阶差分格式,实现了弹性波在数值空间中的逆时延拓。从程函方程出发,采用逆时差分格式求取网格空间中各点的直达波旅行时,以此作为弹性波逆时偏移的成像条件(激发时间成像条件),实现多波多分量资料的逆时偏移。文中给出了几个典型模型的理论记录的偏移结果,数值试验表明,逆时偏移能够使地表接收到的波场准确归位,提高资料处理的精度。  相似文献   

Estimating the windward slope profile of a barchan dune     

Hiroshi Momiji  Steven R. Bishop 《Sedimentology》2002,49(3):467-481

A new theoretical scheme is presented to model the shape of a sand dune at equilibrium that does not require iterative calculations of the interaction between the wind flow and topography. The model is constructed by incorporating theory based on aerodynamics into a grain‐scale model that estimates the shear velocity at the dune crest through the calculation of the sand trapping efficiency of the slipface in the lee of the dune. Published field data, collected in southern Peru, California and southern Morocco, show that as a dune becomes higher the windward slope becomes steeper. For the model proposed, the wind flow over a dune was first assumed to be similar to that over a Gaussian hill. By further assuming a fixed shear velocity on the level surface, the windward slope angle and migration speed of dunes in southern Peru can be explained. To comply with all available data, some aspects are still open to further investigation. However the theoretical insight presented herein implies that the upper limit of dune height may be greater in windier environments.  相似文献   

伊利石测年在焉耆盆地油气成藏时期研究中的应用   总被引：1，自引：0，他引：1  

郑求根  吴冲龙  张育民  全书进 《矿物岩石》2002,22(3):53-56

油气藏成藏时期的确定是进行油气藏勘探与评价的重要工作内容之一。也是揭示成藏过程的有效途径，利用伊利石测年确定油气成藏期，能够得出其绝对年龄，因而受到人们重视，运用自生伊利石同位素年龄测定的原理和方法及自生伊利石同位素年龄资料对焉耆盆地博湖坳陷油气藏成藏时期及油气运移时期进行了分析，最后对自生伊利石同位素测年存在的问题和措施进行了有益的探讨并克服了以往只能根据地质综合研究定性确定油气藏成藏时期及油气运移时期问题，为定量确定油气藏成藏时期以及油气运移时期提供了科学的方法。  相似文献   

Seismic response of adjacent dense and loose saturated sand columns     

K. Adalier  A. -W. Elgamal 《Soil Dynamics and Earthquake Engineering》2002,22(2)

Compaction or densification of loose saturated soils has been the most popular method of reducing earthquake related liquefaction potential. Such compaction of a foundation soil is only economical when limited in extent, leading to a case of an ‘island’ of improved ground (surrounded by unimproved ground). The behavior of the densified sand surrounded by liquefied loose sand during and following earthquakes is of great importance in order to design the compacted area rationally and optimize both safety and economy. This problem is studied herein by means of dynamic centrifuge model tests. The results of three heavily-instrumented dynamic centrifuge tests on saturated models of side-by-side loose and dense sand profiles are discussed. The test results suggest the following concerns as relates to ‘islands’ of densified soil: (1) there is a potential strength degradation in the densified zone as a result of pore pressure increase due to migration of pore fluid into the island from the adjacent loose liquefied ground; (2) there is a potential for lateral deformation (sliding) within the densified island as the surrounding loose soil liquefies.  相似文献