Abstract:A geological section of soft-sediment deformation structures has been found in the strata of the first terrace of the north bank of the Yellow river in Pinglu area in Shanxi. There are three types of soft-sediment deformation structures in the observation section: dish structure, liquefied convolute structure, and ball-and-pillow structure. In order to study the triggering factor of the soft-sediment deformation structures in the study area, the three types of soft-sediment deformation structures are given detailed descriptions and their formation mechanisms are analyzed respectively. The criteria of the soft-sediment deformation structure triggered by earthquake factors are summarized. Through comprehensive comparison, it is indicated that the deformation structures in the section owe their genesis to paleoseismic events. The seismic sequence of Pinglu area in southern Shanxi is established. An optical chronology of the sediments in the section brackets the deformation induced by earthquakes at about 1.9±0.2 ka. Based on the influence intensity calculation and seismic data collected in Shanxi province and adjacent provinces, it is concluded that the two earthquakes may be related to the soft-sediment deformation structures in the section.
SHI Shuangshuang,ZHAO Qiang,BO Jianjie et al. The Paleoseismic Cause of Quaternary Soft-Sediment Deformation Structures on the North Bank of Yellow River, Pinglu, Shanxi[J]. jgg, 2019, 39(10): 997-1001.