Table of Content

03 September 1986, Volume 8 Issue 3

Previous Issue    Next Issue

Brief Report

RECURRENCE INTERVALS OF MAJOR EARTHQUAKES FOR THE KOKTOKAY-ERTAI FAULT

Ge Shumo, Bo Meixiang, Xu Daozun, Xiang Zhiyong

1986, 8(3):  1-9. 

Asbtract ( )   PDF (1423KB) ( )  

Related Articles | Metrics

A number of buried traces associated with paleoearthquake have been found through large-scale excavation,conducted along the Koktokay-Ertai fault,the sites of Haizikou,Tuerhong.Laoshankou,Xinshankou and Ganqou etc.Based on available data of comparable Quaternary sediments and ¹⁴C dating,five paleoearthquakes may be determined.Calculations of the average rate of regional vertical deformation and fault slip yielded a value of 0.3-0.4mm/yr and 3.5mm/yr,respectively;it follows that for 10000 years,the average interoccurrence time for these events is 3150 years.

THE RADIOCARBON DATES OF LATE QUATERNARY SEDIMENTS OF YONGSHENG AND JINGUAN BASINS AND THEIR GEOLOGICAL SIGNIFICANCES

Peng Gui, Jiao Wenqiang

1986, 8(3):  10-10. 

Asbtract ( )   PDF (147KB) ( )  

Related Articles | Metrics

MECHANICAL RESEARCH ON GRAVITATIONAL STRUCTURE——MECHANICAL ANALYSIS OF LISTRIC FAULTS

Chen Qiang

1986, 8(3):  11-31. 

Asbtract ( )   PDF (2412KB) ( )  

Related Articles | Metrics

In this paper,mechanical researches are done for the listric faults of gravitational structure by means of the slip-line field theory obeying parabolic failure criterion.Slopes of gravitational gliding are related to rock strength,thickness of sliding system,pore fluid pressure and lubricating layer;from top to bottom,the listric normal faults change from tensile to tenso-shear,pure shear and compresso-shear and the reverse listric faults are entirely compresso-shear.

FIRST SYMPOSIUM ON PHYSICAL MODEL TEST,HELD IN KUNMING

Wang Wenhu

1986, 8(3):  31-31. 

Asbtract ( )   PDF (174KB) ( )  

Related Articles | Metrics

NATIONAL SYMPOSIUM ON INVESTIGATION OF CONTINENTAL MARGIN ALONG THE SOUTHEAST COAST HELD IN FUJIAN PROVINCE

Wang Xiaoyuan

1986, 8(3):  32-32. 

Asbtract ( )   PDF (10362KB) ( )  

Related Articles | Metrics

THE SEISMOGEOLOGICAL BACKGROUND OF THE WUXIJIANG RESERVOIR-INDUCED SEISMICITY

Xia Qifa, Wang Yongxi, Li Min, Xu Rende, Shen Guangwei, Chen Yuandong

1986, 8(3):  33-43. 

Asbtract ( )   PDF (1687KB) ( )  

Related Articles | Metrics

The Wuxijiang reservoir area has been considered to be geologically and seismologi-tally stable,but frequent microearthquakes were observed in the middle part of the reservoir area after impounding.On the basis of geologic field-work and seismic data,we have described and analysed the seismogeological background of this area,the geological environment of the reservoir,the geological conditions of the epicentral area and the features of the reservoir-induced seismicity.The conditions which induced earthquakes during impounding of the reservoir were compared with those in the Xinfengjiang reservoir.And the trending reservoir-induced seismicity was appraised by using seismogeological anlogic method.During the flood season in 1983,the water level of the reservoir was first over the normal one and the seimicity did not exceed our appraisals.

EVIDENCE ON DEXTRAL DISLOCATION OF FAULT AT THE WESTERN FOOTHILLS OF MT.XIZHOUSHAN,SHANXI PROVINCE AND ITS SLIP RATE DURING THE HOLOCENE

Xu Xiwei, Deng Qidong, You Huichuan

1986, 8(3):  44-46. 

Asbtract ( )   PDF (356KB) ( )  

Related Articles | Metrics

BEHAVIOUR OF EXTENDING GROUND FISSURE IN THE XIAN REGION

Zhu ShuTian, Zhang Jiaming

1986, 8(3):  47-55. 

Asbtract ( )   PDF (1121KB) ( )  

Related Articles | Metrics

In recent years,successively ground motion in the xian,region has aroused extensive scientistific interest.Based on the relationship between the time series of dislacation in vertical,horizontal and extensional derections,and the time series of various factors in the same period,using a regression analysis.It is found that the motion of Xian ground fissure in the study region is not only confined by geoteetonics but also related intensive decline of confined groundwater.This paper will bring us a new approach to the study of ground fissures in the xian region.

PRELIMINARY STUDY ON RELATIONSHIP BETWEEN MECHANICAL PROPERTIES OF GOUGE AND WATER CONTENT

Geng Naiguang, Hao Jinsheng, Li Jihan, Liu Xiaohong, Cai Daien, Fang Yaru

1986, 8(3):  56-60. 

Asbtract ( )   PDF (680KB) ( )  

Related Articles | Metrics

Fault gouge is an important factor which influences fault movement.In this paper the relationship between mechanical properties of gouge and water content is studied by using the experimental data of gouge from five major faults in China.It is found that viscosity.Young's modulus,compressive strength and residual volumetric strain decrease with water content increasing.There is no clear relationship between bulk modulus,wave velocity shear strength and water content.Natural gouge is a mixtutre of clay,debris and water,in which water takes a more complicate role than does the water in the latter two.The importance of the experiment of this kind,therefore,is visible.

PRELIMINARY STUDY ON THE STATE OF ISOSTATiC EQUILIBRIUM IN THE NORTHEAST CHINA

Li Runjiang, Tong Shujuan, Meng Lingshun, Zhang Lin, Zhang Fenghua

1986, 8(3):  61-68. 

Asbtract ( )   PDF (1023KB) ( )  

Related Articles | Metrics

In order to provide some fundamental data,we calculated the isostatic anomalies in most parts of the region (N39?-49?;E121?-131?) by means of Pratt-Hayford isostatic model and using 1白1? square mesh and the isostatic anomaly map of overall region and the 2白2皉egional isostatic anomaly maps were compilated.The calculations show for this region a configuration of anomaly characteristic of alternate anomalies NNE-trending and an extensive anomalous area in agreement with the relief of Moho.It has been shown that isostatic anomalies are generally in agreement with the high relief and regional Bouguer gravity and free-air gravity anomalies,with areas where isostatic anomalies are not or not well concordant with the Moho relief and the their strike,suggesting an isostatic adjustment for these segments,which is likely to be not interpreted as the Moho relief.These segments are in a state of mass imbalance and deserve to pay more attention and further study for the prediction of earthquakes.

THE RELATIONSHIP BETWEEN FOCAL DEPTH AND CRUSTAL STRUCTURE FOR TANGSHAN EARTHQUAKE

Xue Zhizhao

1986, 8(3):  69-78. 

Asbtract ( )   PDF (1292KB) ( )  

Related Articles | Metrics

In this paper,the statistic analysis has been made for the distribution of focal depth based on the data of 8935 earthquakes in the Tangshan area,spanninng from 1976 to 1981.The results obtained show that there are not the same in a magnitude and its distribution is closely correlated with the crustal structure.Increasing earthquake depth gradually varies from NE to SW.The earthquake fault belt,which has an.angle of about 8?with the horizontal plain in the lower part and is in accordance with relief boundary in the upper,passes through the crust and down to the Moho.

PHASE VELOCITIES OF LOVE WAVES IN CHINA AND CALCULATIONS OF CRUSTAL THICKNESS

Sung Zian, Shi Jieshan

1986, 8(3):  79-91. 

Asbtract ( )   PDF (1193KB) ( )  

Related Articles | Metrics

In this paper,the phase velocities of Love waves were determined by using the seis-mograms from fifteen stations in China and three earthquakes from Kamchatka and two from Alaska were under use.Correlations between the phases were in evidence in analyzing the variation of periods with distances and also arrival times of the crests of Love waves in the seismograms.The phase velocities of Love waves were calculated by means of a tripartite array,the velocities of Love waves with periods ranging from 15 to 40 seconds being determind.The thickness of earth crust in different regions were calculated by using Dorman case 208.

FORMATION AND MIGRATION OF DONGZHAI PORT IN THE NORTHERN HAINAN ISLAND AND THE MAJOR QIONGZHOU EARTHQUAKE OF 1605

Xu Qihao

1986, 8(3):  92-96. 

Asbtract ( )   PDF (729KB) ( )  

Related Articles | Metrics

According to available formation and field survey it is confirmed that largescale land subsidence occurred along the present Puqian port during the Qiongzhou earthquake of 1605,leading to changing the Sanjiangshui River course-generation of the tributary (the Dongzhai River).After the earthquake in point,large-scale land subsidence was continuing in a low speed and eventually the present Dongzhai Port that streches into the inland for the largest distance has so far been formed.