Slip tendency of Quaternary faults in southeast Korea under current state of stress

摘要

We present results of mechanical slip tendency analysis on 23 Quaternary faults in southeast Korea based on the fault orientations with respect to the present-day in-situ stress field. The present-day in-situ stress data in 15 locales in the vicinity of clustered Quaternary faults in southeast Korea, collected from the literature, show that the prevailing direction of the maximum horizontal in-situ principal stress trends NE, possibly affected by the preexisting structural discontinuities. The maximum and minimum horizontal stresses relative to vertical stress have ranges of 1.4-1.7 and 1.0-1.2, respectively, and somewhat vary spatially. Thus, the stress field in southeast Korea overall is characterized by predominantly reverse faulting stress regime and partly strike-slip faulting stressregime. When the averaged in-situ stress field is applied to the planes of the Quaternary faults, the ratios of shear to effective normal stress are lower than those of Byerlee’s law.