INFRASTRUCTURES OF LOWER YANGTZE BASIN AND THEIR RELATION TO EVOLUTION OF THE BASIN

Data of seismic sounding from two profiles shot in Yougping county, Jiangxi Province and Shui county, Hubei Province, which have been coupled with characteristics of regional Bouguer gravity anomalies, are digitized and processed to prepare a crustal isopachous map. It is concluded that, in general, the neotectonic movement were taken place in an overall tensional setting. Through tectonic cycles of Yanshan orogeny, Himalayan orogeny, Nworiented compressional movement of Pacific plate against Ryukyu region and the subduction of the Pacific Plate at the Ryukyu trench, the Ryukyu arc was separated from the Asian continent and, parallelling to the arc,the Nw-trending Okinawa trough and the East China Sea basin occured simultaneously in back arc area, resulting in a tectonic pattern of intersection of the present East China Sea basin with the NW-trending North Jiangsu-Southern Yellow Sea basin.