渤海湾盆地东营运动的特征及成因分析

A STUDY ON THE GEOLOGICAL CHARACTERISTICS AND GEODYNAMIC ORIGIN OF DONGYING MOVEMENT,BOHAI BAY BASIN

渤海湾盆地东营运动是一个范围 广泛、强度较大的区域性构造运动， 处在由盆地的裂陷阶段向坳陷阶段 过渡时期。形成了众多小规 模次级断层、全区整体抬升并遭受 剥蚀，局部发育反转构造。该运动以 及渤海湾盆地在伸展裂陷阶段的多 次构造运动说明渤海湾盆 地呈现出幕式沉降过程，东营运动 则具有更重要的动力学意义。岩石 圈快速拉伸、上地幔上涌和温度升高 以及壳下岩石圈的弹性回 返可以很好地解释东营运动的形成 过程以及渤海湾盆地演化阶段的转 折。考虑地壳均衡效 应，可以对传统的地层剥蚀量计算方法进 一步修正。渤海湾盆地东营运动的 形成和发展有利于盆地内油气的生 成和运移。

Dongying movement in Bohai Bay Basin is an intensely regional tectonic movement occurred during late Paleogene. According to the geological features of Dongying Movement in Bohai Bay Basin and the research results of the former, this paper analyzed the potential geodynamic origins of Dongying movement. One is the effect of quick stretching of lithosphere, upwelling and temperature raising of upper mantle, the other is result of the flexibility discrepancy among upper, lower crust and lithosphere under crust during the lithosphere cooling. Furthermore, this paper illustrated the reason of transition of basin evolution style, i.e. from rifting and extension to uplifting and whole subsidence during Dongying movement of Bohai Bay Basin. Based on isostasy principle, this paper made out a correction method for the calculation of disconformity erosion amount. The possible influences of Dongying movement on the formation and accumulation of petroleum reservoir in Bohai Bay Basin were mentioned.