关键词: 下扬子区, 构造演化, 黄桥转换事件, 中生界, 古生界, 苏北—南黄海盆地, 油气勘探

Abstract:

The Lower Yangtze Region consists of the rigid nuclear area of the South Yellow Sea and the cratonic peripheral belt. It was an accretionary terrain formed by the splitting of the south continent and piecing up to the North China Platform with other blocks during the Mesozoic. The terrain collision resulted in ramp-nappe structures that the Jiaodong massif in the northwest part napped southeastward and the Jiangnan Uplift in the south-east part napped northwestward, and slidding-fault system in the whole region. A seriesof nappe detuching planes existed in the Lower Yangtze Region, which were acturally the foreland basin between the folded mountains in the south and north sides. After the Huangqiao tansform event (K₂), this area was brought into the Pacific Ocean structuraldomain and changed into tensile environment which developed Cretaceous-Tertiary fault-depressed basins. The above mentioned evolution process determined the complexity of theoil-gas geological environment. It is considered that favourable place for hydrocarbon exploration is North Jiangsu-South Yellow Sea Basin, the best of which is the area to the east part of Yancheng-Ningguo line.