Research On The Active Faults In Changchun City

In recent years, the global seismic frequently occurrence,which was triggered bythe active fault, research on the seismic active fault is particularly important forunderstanding the earthquake mechanisms and predict the future activities of thecrust, the earthquake which was occurred in the city is destructive of human life andeconomic construction, probing the activities of active fault in urban can lay thefoundation work for predict the earthquake, this paper focused on solving theprovincial capital in Jilin Province, Changchun City’s active fault detection, find outthe activity of the main fault in Changchun City, which was lay the foundation forforecasting urban earthquake.The first process of the study was by collating a large number of geologicaldatas in Changchun City, summarize the geological structure backgroundcharacteristics of the study area, find out the formation and distribution of thefeatures, the main faults are the Kaiyuanbao-Small town fracture （F₁）, Jianshanzi-Kalun fracture （F₂）, stone ridge fracture （F8） and the west branch of Yishu fracture(F₁₀) in North East, the northern section of Fanjiatun-Wujiazi fracture （F₃）, SouthLake-Sangjiawobao fracture（F₄）, Jingyue-Smalltown-Dahelong fracture （F₅） andQuanyangou-Yaofenshuiling fracture （F9）in north-west; the middle segment of Yitongriver fault （F₆） and Jia jiawazi fracture （F7） in north-south; In recent years, seismicactivity is weak, early seismic activity is mainly concentrated in the northeast of thestudy area, the earthquake’s occurence may releated with F₁、F₂faults’ activity; lateperiod seismic activity is mainly concentrated in the southeast of the study area,seismic activity may be associated with F₄、F₆faults’ activities.30years since theearthquake occurred mainly in the east segment of the Yitong river fault （F₆） innorth-south, show that the east crust of Yitong river fracture （F₆） is relatively active;combination of the results of the remote sensing interpretation and field seismic geological survey,identified the major active faults in Changchun City were theKaiyuanbao-Small.town.fault（F₁）,Jianshanzi-Kalun.fault（F₂）,South.Lake-Sangjiawobao fault（F₄）, Yitong river fault （F₆）; Second, by develop controlling drilling inChangchun City, combined with the wild、artificial excavation of outcrop sedimentsprofiles,collection samples, combined with ESR dating method, derived stratigraphicage,plotted joint exploration drilling profile, in order to make basic work for the studyof fault faulted stratigraphic;Finally,using remote sensing methods, observating thefield geological features and combining a variety of active fault detection geophysicalmethods, which are using in detecting the active faults in the city currently,in order toresearch.the.active.faults.in.Changchun.City,find.out.the.spatial.distribution,occurrence,fault length and width, activity times and ground deformation characteristicparameters,el.Comprehensive analysis to determine the nature of active faults inChangchun City,analysis showed that the Kaiyuanbao-Small town fault （F₁） actived inthe Cretaceous era,never active after Quaternary,the formation is before theQuaternary,fault activity dominated by normal faults; Jianshanzi-Kalun fault （F₂）actived in the early Quaternary era,which is a normal fault;South Lake-Sangjiawobaofault （F₄）is a active fault in the early stages of Quaternary,there is no significant activephenomenon since the Quaternary Pleistocene date;Yitong river fault （F₆） is earlyQuaternary active faults,which is mainly performance in normal fault movement.Study faults’ activity has great significance in predicting earthquakes and othergeological disasters,take response measures early to protect the human livingenvironment and promote social development,also can be used for the inversion ofcrustal stability,it has high academic value,which has been the focus of regionalGeological Survey、the study environmental engineering; in a scientific point of viewto detect activities of faults in Changchun City is a strong practical requirement toidentify the specific location of the active faults and activities, which can reduce andprevent the earthquake disaster in Changchun City,which is the foundation work topromote urban construction and programme,safeguarding the sustainable developmentof Changchun City, protecting people’s lives and safety,which is the important work topromote the harmonious development of Changchun City.