The displacement-length relationship of faults and its significance
DONG Jin~(1,2), ZHANG Shi-hong~(1,2), JIANG Yong-biao~3 (1. School of the Earth and Land Resources, China University of Geosciences, Beijing 100083, China; 2. The Key Laboratory of Lithosphere Tectonics and Exploration, China University of Geoscience, Ministry of Education, Beijing 100083, China; 3. Geoscience and Geomatics Department, East China Institute of Technology, Fuzhou 344000, China)
Displacement-length relationship is a common method in research on normal faults in recent years. It provides a basis for extrapolating a two-dimensional view of faults into the third dimension. The authors present some factors that influence the geometry of the displacement-distance profiles of normal faults,such as the plastic deformation in the end of faults,host-rock stiffness, remote tensile stresses, and the interaction and linkage of faults. According to the geometry of the displacement-distance profiles and the stages in the development of normal faults, the authors separate the pattern of displacement into three classes: (1) symmetrical elliptical or bell shaped for single simple faults; (2) asymmetrical elliptical or bell shaped for interactive faults; (3) serrated shaped for linked faults. The authors describe some structures that are formed simultaneously with the fault, for instance the relay ramps, the intrabasin high, and so on. These structures are corresponding to the position of the interaction and linkage of faults. There are two kinds of method of measuring the displacement and length of faults as follows: measuring is done on the surface, and the other is on the subsurface. Note that the eroded part needs to be reconstructed before the faults are measured. It is of great significance to study the displacement-length relationship for faults in the development of basin, the evolution of faults and hydrocarbon exploration.