Evolution of the Extensional Rifted Yunnan-Guizhou-Guangxi Oceanic Basin During the Late Hercynian to Middle Indosinian Stage     

Xia Wenchen  Zhou Jie  Lei Jianxi  Zhang Nianmao  Peng YangChina U niversity of Geoscience  W uhan  Hubei Wang Yujun 《《地质学报》英文版》1995,69(4):341-357

On the basis of exhaustive researches on the facies sequences and depositlonal evolutionary process of various depositional systems, the genetic stratigraphic framework of the extensional rifted oceanic basin, which has undergone strong structural destruction, has been reconstructed by means of dynamic genetic stratigraphic analysis. Five depositional episodes have been distinguished from various isochronous stratigraphic boundaries and stratigraphic sequences with the three-dimensional structure of each depositional episode analysed in detail. The tectonic paleogeographic environment corresponding to different stages of each depositional episode has been reconstructed for individual depositional system tracts. And the evolution history of this rifted basin has been divided into four stages' initial rifting and oceanization of continental crust, stretching and spreading of the basin, subduction and basin differentiation, and convergence and collision. A NNE-trending intracontinental soft collision sutur  相似文献   

近四年来我国气候数值模拟与预报研究的进展     

罗勇 《地球科学进展》1995,10(5):436-441

近年来，我国在气候问题中的数值模拟式研究方面有了相当大的发展。这主要表现在气候模式水平的迅速提高，以及利用气候模式进行了大量的气候数值模拟和预报试验研究工作。对我国１９９１￣１９９４年在这方面的主要研究进展进行了系统的总结。  相似文献   

四川盆地基底及深部地质结构研究的进展   总被引：6，自引：1，他引：6  

宋鸿彪  罗志立 《地学前缘》1995,(4)

根据对近年来区域地质、多种地球物理资料和深钻井资料的综合研究，认为四川盆地属扬子板块，岩石圈巨厚，最厚可达２００ｋｍ。川西高原属青藏板块的东缘，同时位于中国南北构造带中段，软流圈呈北东向上隆，岩石圈减薄，其最薄处厚度约７０ｋｍ左右。四川盆地的基底由结晶基底与沉积岩变质基底组成，上震旦统为该地区在扬子古板块形成后的第一套沉积盖层。基底的性质、厚度、埋深在不同地区各不相同，从而决定了盆地内部构造区的划分。基底深断裂对盆地的形成与盖层构造的发展也有重要的控制作用。  相似文献   

Paleoseismicity and Segmentation Along the Active Fault at the Northern Boundary of Huailai-Zhuolu Basin,Hebei Province     

Ran Yongkang  Fang Zhongjing  Li Zhiyi  Wang Jingbo  and Li RuchengInstitute of Geology  SSB  Beijing  China 《中国地震研究》1995,(1)

The northern boundary fault of Huailai-Zhuolu basin,Hebei Province,has a total length of 58 km and a general strike of NE.The geometry and feature of activity of the 5 segments of the fault greatly differ from each other.17 paleoseismic events have been recognized within 11 trenches excavated along the different segments of the fault.It is found that each segment is characterized by its distinct recurrence of paleoearthquakes.The recurrence intervals of strong earthquakes for each segment are 3500-7000 a for the shortest and 17,000-20,500 a for the longest.However,the recurrence interval of strong earthquakes for whole fault ranges between 750-8500 a.The boundary of the segments can be recognized as the junction,gap,bending,jog and salient of the fault.The length of the segment ranges between 7.5-14 km.  相似文献   

Measurements of Powder Snow Avalanches- Laboratory -     

Stefan Keller 《Surveys in Geophysics》1995,16(5-6):661-670

Laboratory simulation of powder snow avalanches serves for the validation of numerical models and as a tool in its own right for consulting and research purposes. Two-phase gravity currents are simulated in water with quartz powder or glass spheres as the particle phase. Particle-phase velocity profiles and particle-phase volume fraction profiles are measured with an ultrasonic device. The experimental setup and the current state of the measurement technique are described and preliminary results are presented.  相似文献   

Simulation of the hydrocarbon structures using the P-SV wave solution     

Avadh Ram  J. P. Narayan 《Pure and Applied Geophysics》1995,144(1):59-77

Numerical solution of the scalar and elastic wave equations has greatly aided geophysicists in modeling seismic wave fields in the complicated geologic structures containing hydrocarbons and hence increases the geologic interpretation. Finite-difference method offers a versatile approach to compute synthetic seismograms numerically for given subsurface complex geological structures. To avoid the spatial derivative of the elastic parameters and density, elastodynamic equation (first-order hyperbolic equation) has been solved using the Lax-Wendroff scheme. A numerical finite-difference modeling program has been developed for the P-SV wave using the above solution. A line source with a time delay of 0.015s and dominant frequency of 120 Hz has been utilized in the simulation. In order to avoid the large values of the displacement vector in the source region,Alterman andKaral's method (1968) has been utilized. Horizontal and vertical component synthetic seismograms have been computed for two different geological models with and without oil and gas bearing zones. It has been concluded from the response that a finite-difference technique not only yields the relative arrival times but also accounts for the variation in amplitude and phase according to the elastic impedance contrast across the interfaces. It should come as no surprise to learn that in spite of the limitation of this numerical method, the scheme has provided a valid response for the thin layer, high acoustic impedance contrast and the pinch out.  相似文献   

Source models for the 1993 Hokkaido Nansei-Oki earthquake tsunami   总被引：1，自引：0，他引：1  

Tomoyuki Takahashi  Takeyuki Takahashi  Nobuo Shuto  Fumihiko Imamura  Modesto Ortiz 《Pure and Applied Geophysics》1995,144(3-4):747-767

A source model for the 1993 Hokkaido Nansei-Oki tsunami must satisfy certain conditions. Such conditions are presented in this paper, and two methods are used to determine the best source model for this event. A trial-and-error method selects DCRC-17a as the best among 24 different models. This model has three fault planes dipping westward. To reproduce well the tide gauge records at two locations, an inversion analysis is used to modify the dislocation of DCRC-17a.  相似文献   

复杂构造应力扰动场与发震构造识别问题的研究   总被引：7，自引：2，他引：7  

马瑾  刘力强 《地震地质》1995,17(4):372-382

在地震短临阶段异常是由局部断层扩展或弱化引起。实验与数值模拟结果曾得到与之相伴的是平均应力扰动场的四象限分布和最大剪应力扰动场的八瓣式分布。为检验此结果的普适性作了进一步的研究。结果表明不论区域构造及其基本应力场如何复杂，这种四象限分布与八瓣式分布型式不变，这为最终判定失稳区提供了依据。与此同时，在复杂构造情况下这种应力扰动场的畸变也不容忽视  相似文献   

地震能量空间分布局域标度特性的初步研究   总被引：2，自引：1，他引：2  

蒋海昆  王忠民 《地震研究》1995,18(4):357-364

本文利用计算机数值模拟数据及大同地区三次中强地震前后的地震记录资料，在空间能量分布“漫化”的基础上，通过多重分形方法着重对能量空间分布的局域标度性质及可能的震兆信息进行研究。结果表明能量分布普遍地表现出多标度分形特性，但相同ｑ值Ｄｑ的时间变化或Ｄｑ￣ｑ谱形态变化不明显。中强地震前标度指数谱ｆ（α）￣α曲线由两端大体对称或右端略低变为左端明显下降，同时α及ｆ（α）数值分布范围扩展、顶点右移。计算机模  相似文献   

滆湖沉积物理化特征及磷释放腄   总被引：4，自引：0，他引：4  

范成新 《湖泊科学》1995,(4)

对滆湖表层底泥、柱状层祥和间隙水进行理化分析,模拟不同条件下的沉积物磷释放。结果表明,0～20cm深度范围内,各项理化指标变化较大;大于2cm后差异较小。当提高沉积物-水体系温度、降低氧含量(或Eh),提高pH及施以水动力作用时,可促进沉积物磷释放进程。无菌条件对磷释放有抑制作用。采用实验室模拟和间隙水浓度扩散模型计算得到的磷总释放量分别为10.65t/a和9.40t/a,其中湖面网围区释放量占全湖总量的28.2～35.4％。建议适度控制网围养殖规模,以减少内源磷污染。  相似文献