Abstract: Ternary structural inversion structures are one of the most typical structural styles in the Doseo Basin, but research on their geometric characteristics, genetic mechanisms and geological significance remains entirely unexplored. Based on theories of plate tectonics, structural geology, petroleum geology and sedimentology, this study applies techniques such as seismic fine interpretation and structural analysis to investigate the geometric characteristics and geological significance of the ternary structural inversion structures in the Doseo Basin. The results indicate that ternary structural inversion structures can be divided into three types based on boundary convergence degree: bilateral strong convergence type, bilateral weak convergence type, and unilateral convergence type; based on mirror plane morphology, they can be divided into recumbent S-type, sickle-shaped, and approximately straight-line types; tectonic inversion during the Late Cretaceous Santonian and Maastrichtian periods controls the formation of ternary structural inversion structures; the widely developed ternary structural inversion structures throughout the basin clearly indicate that the basin inversion intensity is moderate; on the plane, ternary structural inversion structures are distributed near the Borogop Fault, some are located between the Borogop Fault and the eastern inverted anticline zone I, and on the eastern inverted anticline zone I. These areas all represent significant future exploration targets. The research results have guiding significance for deepening and enriching inversion structural styles and inversion structural theory and provide certain technical support for oil and gas exploration deployment.

Key words: Central African Shear Zone, Doseo Basin, ternary structural inversion structure, mirror plane, genetic mechanism, indicative significance