PRELIMINARY STUDY OF ACTIVE STRUCTURE OF THE 1830 CIXIAN STRONG EARTHQUAKE AREA IN HEBEI PROVINCE

According to the aerophone interpretation and field investigation, this paper shows there is a Holocene uplift belt striking NWW in Cixian County area. The NWW Nanshancun fault on the north of the uplift belt is an active fault, which is a normal dip-slip fault and has a little left-lateral strikeslip on the basis of coal geological information. Along the active fault, there are large-scale bedrock scarps and the wedge in which loess and broken stone can be found. In the late Holocene system there are scarps. This active fault is considered as the seismic-fault of the 1830 Cixian earthquake with magnitude 7.5.