中国东部主要盆地断坳结构形成机理的探讨

Study on Forming Mechanism of Fault Sag Structures in Main Basins in East China

箕状断陷类型可分为对翘、反翘和单翘型，其形成是由于盆地中古隆起抬升导致拉张所致，而上覆坳陷型盆地则是侧向挤压所致。中央隆升力和侧向挤压力的形成取决于板块俯冲倾角的大小。实践证明不论断陷、坳陷构造层，只要有丰富的有机质堆积和油气演化的热作用，都可形成含油气构造单元。

The halfgraben-like fault depression can be divided into three types as fOllows:butt upwarp,anti-upwarp and single upwarp. Its forming is because of tension by palaeohigh arching in basin. But the overlying downwarped basin is resulted from lateral compression. Forming of the force of center uplifting and lateral compressing depends on the size of dip angle of plate subduction. It has proven by practice that fault depressing or downwarping structural layers can form oil-bearing structural units, if there are rich organic accumulations and thermal degradation for hydrocarbon evolution.