STRUCTURAL STYLE OF A TENSO-SHEAR FAULT BASIN

In order to study the properties and structural types of a tenso-shear fault basin, the Shengli Offshore Region of central-southern Bohai Bay Basin is selected as a case for geological and geophysical studies. Results show that (1) the region is dominated by a tectonic environment of tenso-shear fault subsidence. The structural style of the region is controlled by the stress field and tectonic evolution. Extensional, shearing, and reversal structural styles are developed in the region; (2) extensional structural style can be further divided into four categories of tilting block, buried-hill drape, gravity antiform, and diapir antiform and nine types; (3) shearing structural style can be divided to two categories of flower structure and echelon structure. In the end, the characteristics and mechanism of different structural types are summarized.