THE REPRODUCTION OF PALEO-STRUCTURE AND THE ESTABLISH OF EQUILIBRIUM PROFILE FOR EXTENSION STRUCTURE AREA——An Example of Bohai Gulf Basin

The severe denudaticn and reworks in Bohai Gulf Basin changed the geometric configuration, the rock volume, and the formation distribution of fault blocks.In addition, the occurrence of Cenozoic extension associated with shearing deformation in the basin changed the total rock area of the profile which meets the structure line at right angle. The two factors mentioned above would directly influence the quality of paleo-structure reproduction. Taking Bohai Gulf Basin as an example, the author of this paper suggested the analysis on geological reproduction combined with geometric mapping based on geological characters of extension-structure regions. Such a kind of analysis would take non-rigid tilting fault blocks as subjects and reconstruct the initial configurations of various fault blocks by reproducing the denuded rock volume without subsequent reworks of structural deformation. Thereafter, the paleo-structures would be progres-sively reprepoduced following the sequence of fault block, longitudinal section, cross-section, space and timing. Thus, the reproduction of Paleo-structural configuration in the structural extension regions Can be made, the amount of extension is quantified and the equilibrium profile can be established with good quality.