Subsidence history of the Gunsan Basin (Cretaceous-Cenozoic) in the Yellow Sea, offshore korea

Rifting in the Gunsan Basin between China and Korea started in late Mesozoic times, due to large-scale interaction between the Pacific, Eurasian and Indian plates. To analyze the detailed tectonic evolution of this basin, backstripping the subsidence history of four representative units in the basin has been undertaken including sag and half-graben structures in the Central sub-basin as well
as half-graben and graben structures in the SW sub-basin. Backstripping indicates that the subsidence history of the Gunsan Basin can be grouped into a Late Cretaceous-Oligocene a main subsidence phase and a Middle Miocene-present secondary subsidence phase. These phases were separated by an uplift and erosion phase during early Miocene times. The main subsidence phase comprised a rapid Late Cretaceous-Paleocene subsidence event and a slower Eocene-Oligocene subsidence event. These phases can be correlated to seismic sequence MSQ I, II and III, identified in the SW sub-basin from seismic stratigraphy, and can further be related to the convergence of the Pacific, Eurasian and Indian plates. Compared with the McKenzie (1978) lithospheric stretching model, this basin is relatively similar to the typical tectonic subsidence characteristics of intracontinental basins.