The Mesozoic and Palaeozoic strata in the Lower Yangtze Region, particularly in the Yanfu area of northern Jiangsu Province have been studied using drill hole, well log and paleontological data, as well as gravity, magnetic, electrical, 2-D seismic, and 2-D MT data. Spatial distribution of the Mesozoic and Palaeozoic strata is described. The Late Cretaceous Pukou Formation is very thick and distributed widely. But the Chishan Formation, the Gecun Formation, and the Triassic-Jurassic strata have a sporadic spatial distribution. Upper Paleozoic strata are distributed mainly in a zone from the Binghai uplift to the Jianhu uplift to the Yinshuigou uplift, and Lower Palaeozoic strata are distributed mainly in a zone from the Huaiyin sag to the Yancheng sag.
