ABSTRACT
The Longxian-Qishan-Mazhao Fault is important boundary tectonics on the southwest edge of the Ordos Block, which has obvious sinistral strike-slip characteristics. It was found from a field survey that the Longxian-Qishan-Mazhao Fault has the phenomenon of “vertically dislocating” the Quaternary aeolian loess–paleosol. To clarify the cause of its formation, three typical geological sections of the fault were analyzed. The result shows that the “vertical dislocation” observed in the field is mainly the false appearance caused by the strike-slip movement of the fault. To further strengthen the cognition of the sections of the Longxian-Qishan-Mazhao Fault, by considering the geometric elements and constraints controlling the stratum of fault sections, the pseudo effect model of normal/reverse fault formed by strike-slip movement is supplemented and improved, which provides a basis for the study of fault activity and seismic risk in similar areas.
