Comprehensive Multi-Level Exploration of Buried Active Faults： an Example of the Yinchuan Buried Active Fault     

Chai Chizhang 《中国地震研究》2007,21(3):225-235

The paper introduces the steps and methods of multi-approach,multi-level exploration of buried faults in thick Quaternary sediment regions by taking the test exploration of the Yinchuan active fault as example.Based on the comprehensive analyses of previous data,we choose the Xinqushao Village of Xingqing District of Yinchuan City as the test site for the comprehensive exploration.Firstly,we adopted shallow seismic investigation with group intervals of 10m,5m and 1m to gradually trace layer by layer the master fault of the Yinchuan buried fault from a deep depth to a shallow depth where drilling could be used.Then,with composite geological profile drilling,we determined the precise location and dip angle of the fault.The drilling show the buried depth of the upper offset point is 8.3m.Finally,large-scale trenching revealed that the actual buried depth of the upper offset point of the fault is 1.5m from the ground surface and there are paleoearthquake events of 5 stages.Combined with the preliminary result of corresponding sample age,we conclude the Yinchuan buried fault is a mid to late Holocene active fault.  相似文献   

Characteristics and method of synthesis seismic wave based on wavelet reconstruction     

邹立华  刘爱平杨宏 柴新建尚歆  戴素亮董博 《地震学报(英文版)》2007,20(6):675-683

A novel method of synthesizing seismic wave using wavelet reconstruction is proposed and compared with the traditional method of using theory of Fourier transform. By adjusting the frequency band energy and taking it as criterion, the formula of synthesizing seismic wave is deduced. Using the design parameters specified in Chinese Seismic Design Code for buildings, seismic waves are synthesized. Moreover, the method of selecting wavelet bases in synthesizing seismic wave and the influence of the damping ratio on synthesizing results are analyzed. The results show that the synthesis seismic waves using wavelet bases can represent the characteristics of the seismic wave as well as the ground characteristic period, and have good time-frequency non-stationary.  相似文献   

拉张状态下方解石组构的递进变形规律     

宋传中  钱德玲 《西北地质科学》1995,16(2):23-28

拉张状态下方解石组构多星环带到，递进变形状态下才可能出现点极密．因为当分解剪应力达最大值时，含有众多方解石颗粒的岩石中，形成ｅ双晶滑动最有利的方位不可能是唯一的，而是不同方位的滑动系在三维空间中的组合，并且ｅ双晶极点和光轴各自构成古钟型。由于系同一应力作用下的产物，二钟型体的顶角大小不同，但彼此共轴，均平行主任应力方向，属共轴叠钟体。该叠钟体记录了岩石变形时的应力状态，未再变形之前，该组构为初始组构。岩石的递进变形过程，实际是初始组构的递进变形过程，最后形成定型组构．岩石递进变形的全过程，就是初始组构到定型组构的全过程．  相似文献   

海洋沉积物可溶铁测定条件的探讨     

陈荣星  王维法  何琳琳  吴金珍 《上海国土资源》1993,(4)

海洋沉积物可溶铁Fe~(3+)/Fe~(2+)比值,已被海洋地质工作者作为海洋油气化探的一项间接指标应用于东海油气化探中。这种铁的含量受提取酸的种类、浓度、样品微沸时间、放置时间等条件的影响。必须采用统一的可溶铁测定方法,只有在同一标准条件下测定的海洋沉积物可溶铁结果才有对比意义。  相似文献   

首届全国地震工作好新闻评选活动概况     

柴保平  王伟 《国际地震动态》1993,(6):17-19

  相似文献   

Effect of near-fault earthquake on bridges: lessons learned from Chi-Chi earthquake   总被引：4，自引：1，他引：3  

Chin-Hsiung?LohEmail author  Wen-I?Liao  Juin-Fu?Chai 《地震工程与工程振动(英文版)》2002,1(1):86-93

The objective of this paper is to describe the lessons learned and actions that have been taken related to the seismic design of bridge structures after the Chi-Chi, Taiwan earthquake. Much variable near-fault ground motion data was collected from the rupture of Chelungpu fault during the Chi-Chi earthquake, allowing the seismic response of bridge structures subjected to these near-fault ground motions to be carefully examined. To study the near-fault ground motion effect on bridge seismic design codes, a two-level seismic design of bridge structures was developed and implemented. This design code reflects the near-fault factors in the seismic design forces. Finally, a risk assessment methodology, based on bridge vulnerability, is also developed to assist in decisions for reducing seismic risk due to failure of bridges. Director of Center for Research on Earthquake Engineering. Supported by: the Science Council, Chinese Taipei, under grant no. SC 90-2211-E-002-028.  相似文献   

Determination of Bromine and Iodine in Twenty-three Geochemical Reference Materials by ICP-MS   总被引：1，自引：0，他引：1  

Jian Y. Chai  Yasuyuki Muramatsu 《Geostandards and Geoanalytical Research》2007,31(2):143-150

Trace amounts (from nanogram to microgram levels) of bromine and iodine were determined by inductively coupled plasma-mass spectrometry (ICP-MS) in twenty-three geochemical reference materials issued by the GSJ, USGS, IAEA etc. The pyrohydrolysis technique was used to separate bromine and iodine from samples analysed in the form of powder. The accuracy and precision of the experimental values were assessed by the comparative analysis of well established reference materials such as USGS AGV-1, BCR-1 and IGGE GBW07312. The measured values agreed well with reported values within a 10% error range. We also report reliable new data for these elements in these geochemical reference materials.  相似文献   

Quaternary Tectonic Deformation in Front Area of the Tianjingshan Fault Zone and Analysis of Its Genesis     

Chai Chizhang  Zhang Weiqi  and Jiao DechengSeismological Bureau of Ningxia Hui Autonomous Region  Yinchuan  China 《中国地震研究》1998,(4)

Through detailed field mapping, the tectonic deformation in the front area of the Tianjingshan fault zone is discussed in this paper. The result shows that there are two Quaternary thrust (oblique) fault-fold belts, namely: the Miaoshan and Hongjianshan fault-fold belts, in the front area of the south wall's strike-slip movement of the Tianjingshan fault zone. The Hejiakouzi Quaternary anticline, which is a part of the Miaoshan fault-fold belt, is mainly discussed. It is pointed out that the fold began to grow in the middle part near Hejiakouzi in the mid-late stage of middle Pleistocene epoch and then gradually developed towards the ends in late Quaternary. Based on the Cenozoic structural features, the genesis of the Miaoshan and Hongjianshan fault-fold belts and the kinematic relation they bear with the Tianjingshan fault zone are analyzed.  相似文献   

喇嘛苏铜矿床斑岩体地质地球化学特征及含矿性评价   总被引：5，自引：0，他引：5  

蔡宏渊  郑跃鹏 《矿产与地质》1998,12(6):386-392

矿区内广泛发育以斜长花岗斑岩和花岗闪长斑岩为主的中酸性斑岩体。斑岩的结构特征反映出岩浆浅成侵位成因。研究表明该区斑岩具有相对富硅和富碱高钾的岩石化学特征,属钙碱性系列;具有Ｃｕ、Ａｇ、Ｂｉ等成矿元素高丰度的微量元素地球化学特征和低ΣＲＥＥ与高δＥｕ值的稀土地球化学特征。矿区内铜矿化富集在斑岩体内外接触带,斑岩体深源浅成特点和富碱高钾岩石化学特征于铜矿化富集有利。Ｃｕ、Ａｇ等成矿元素高丰度及其与矿化类型一致性说明成矿与岩浆活动有密切成因关系。  相似文献   

A new aspect of condensation theory     

James W. Telford  Steven K. Chai 《Pure and Applied Geophysics》1980,118(2):720-742

This paper examines the effects of the mixing of dry air into a cloud top from the point of view of the droplet spectra. It is shown theoretically that the resulting cycling of the air up and down in the cloud, as seems to be the essential mechanism by which cumuli have been diluted to their observed liquid water mixing ratio, can double the largest drop radius and generate cloud parcels containing drops of all sizes up to this maximum. These changes in the droplet distribution with size occur by a process which is not greatly influenced by the cloud condensation nuclei or the details of droplet growth since maritime like spectra can develop in continental type cumuli. It shows that large numbers of cloud condensation nuclei should not have much effect in inhibiting the rainforming process by reducing coalescence growth. On the contrary, the controlling parameters which determine precipitation efficiency and times seem to be those which control the mixing.  相似文献