Tectonic subsidence and evolution of the Gaoyou depression in northern Jiangsu Basin during the Late Cretaceous to the Cenozoic

The analysis of the subsidence history of the Gaoyou depression in northern Jiangsu basin during the Late Cretaceous to the Cenozoic is concerned with the decompaction correction based on the backstripping method and stratigraphic framework thickness model of the sedimentary strata in the Gaoyou depression,estimation of the thickness of the denudational strata in the depression during the latest Sanduoan based on the time difference of acoustic waves and vitrinite reflectivity,and calculation of the tectonic subsidence and total subsidence in the depression based on the Airy isostasy hypothesis.The results of research show that the Gaoyou depression is a typical rift basin,and has gone through the evolutionary stages of downwarping-faulting,faulting-downwarping,and rift faulting-downwarping,including three phases of subsidence and two phases of uplifting.The depocenters in individual stages are all controlled by main boundary faults,and display a beaded alignment around the boundary faults.