Seismic Survey Result of Ninghe Area and Charactertistics of Tongcheng Fault in Shallow Lateral Structure
DOI:
Author:
Affiliation:

Clc Number:

Fund Project:

  • Article
  • |
  • Figures
  • |
  • Metrics
  • |
  • Reference
  • |
  • Related
  • |
  • Cited by
  • |
  • Materials
  • |
  • Comments
    Abstract:

    Objectives:Tongcheng fault is located between the Jixian uplift and the Huanghua depression. Before the Tangshan Ms7.8 earthquake in 1976, the strong crustal deformation of the Tongcheng fault has been observed. We use shallow seismic exploration methods to identify structural features of the Tongcheng fault. It is believed that the large deformation of the Ninghe crossfault monitoring site reflects the vertical motion characteristics of the F2 and F3.Methods:In this study, shallow seismic exploration methods are used in the study area, and two shallow artificial seismic geophysical profiles near the north—south direction are laid. We obtain two highquality superposition time and depth profiles and the structural characteristics of the target fault are identified.Results:According to the stratigraphic characteristics of the study area and the structural characteristics of the Tongcheng fault, the fault is considered to be a midPleistocene active fault. It is preliminarily believed that the fault zone is “flowerlike” in the shallow part and tends to converge downward. Conclusions:The Tongcheng fault is an active fault that reflects the crustal deformation of the Tangshan earthquake and is the dividing line between the Cangxian uplift and the northern part of the Huanghua depression. In this study, two shallow artificial geophysical prospecting sections are arranged at the crossfault site of Ninghe according to the shallow seismic exploration methods. And the structural characteristics of the target fracture are identified on the basis of two highquality superposition time and depth profiles which are reflecting different depths of the Tongcheng fault. In this work, seven faults are detected in the study area. It is found that the Tongcheng fault is a fault zone composed of multiple primary faults and secondary faults. However, the work line is relatively short and the detection depth is limited. Therefore, by summarizing the results of seismic exploration around the study area by experts and scholars from relevant departments, it is preliminarily believed that the fault zone is “flowerlike” in the shallow part and tends to converge downward. In addition, combined with previous scholars’ research on borehole and stratum in the study area and surrounding areas, through the comparison of borehole strata, Tongcheng fault is considered to be a midPleistocene active fault. According to the exact coordinates of the breakpoint on the fault and characteristics of the Tongcheng fault, it is found that F2, F3 and F4 are effectively monitored in the crossfault monitoring sites in Ninghe. According to previous studies on the stress in the study area, the large deformation in Ninghe Field reflects the vertical movement characteristics of two faults F2 and F3. However, the relationship between its deformation characteristics and the Tangshan earthquake needs further exploration.

    Reference
    Related
    Cited by
Get Citation

YIN Haiquan, HE Qinglong, WANG Shengwen, XU Yujian, CHANG Ming.2018. Seismic Survey Result of Ninghe Area and Charactertistics of Tongcheng Fault in Shallow Lateral Structure[J]. Geological Review,64(5):1132-1140.

Copy
Share
Article Metrics
  • Abstract:
  • PDF:
  • HTML:
  • Cited by:
History
  • Received:December 27,2017
  • Revised:July 20,2018
  • Adopted:
  • Online: September 14,2018
  • Published: