南黄海北部盆地是我国近海海域中唯一由中生代陆-陆碰撞造山作用形成的前陆盆地。其构造演化经历了4个阶段:(1)前造山期大陆边缘盆地阶段(Z—T2);(2)苏鲁造山带晚期前陆盆地阶段(J3—K);(3)造山期后陆内断陷盆地阶段(K2t—E);(4)区域沉降覆盖阶段(N—Q)。对其中陆内断陷盆地的详细调查研究结果表明,盆地内晚白垩世泰州组烃源岩发育,具有4套储盖组合,圈闭构造多,成藏配套条件好,计算其石油资源量约20×108t,是当前在南黄海获取油气重要突破的首选区域。
The northern basin of the South Yellow Sea is the only foreland basin formed by land-land collision orogeny during the Mesozoic era in the offshore region of China,and can be divided into four stages in terms of tectonic evolution:(1)the passive continental margin basin stage before the orogenics(Z-T2);(2)the foreland basin stage in the late phase of the Su-Lu orogenic process(J3-K);(3)the post-orogenic intracontinental faulted basin stage(K2t-E);(4)the regional subsidence and coverage stage(N-Q).The detailed investigation results of the intracontinental faulted basin indicate that the source rocks of the late Cretaceous period in the basin are well developed,and that they feature four combinations of reservoir and cover rocks,numerous trap structures,and excellent pool-forming conditions.This is the primary target of key oil and gas breakthroughs today in the South Yellow Sea,and the oil resource amount is estimated at about 20×108 t,which is of strategic significance for breaking the deadlock in oil and gas exploration in the South Yellow Sea.