CHRONOLOGICAL STUDIES ON ACTIVE FAULTS AND GROUND FISSURES IN GUANZHONG AREA, SHAANXI PROVINCE,CHINA

12 Thermoluminecence datings of the fault gouge and the adjoining cleaved loess of the area gives an age of 20-240 ka B P.It shows that the faults have been active during the late middle pleistocene to Late Pleistocene.Geomorphological and geological evidences are provided to show the alternation of rapid movement and show creep of the faults.The ground fissures in Xi'an City are in fact active faults,having been triggered to revive by pumping water from the confined aquifer.