渤海湾盆地早第三纪构造样式的演化

在伸展和走滑两种活动体制下,渤海湾盆地早第三纪构造样式有五种类型.孔店-沙四期主要发育非旋转地堑、旋转半地堑、滚动半地堑和走滑地堑,沙三-沙二期以滚动半地堑和复式半地堑为主,沙一-东营期主要发育滚动半地堑、复式半地堑和走滑地堑.盆地构造样式的演化遵循着三个序列,即旋转半地堑→滚动半地堑→复式半地堑序列、非旋转地堑→滚动半地堑→复式半地堑序列和非旋转地堑→走滑地堑序列.演化序列本身存在差异并受断裂活动的控制.构造样式的演化具有明显的地区性特点,后两种序列沿郯庐断裂带、沧东-兰聊断裂带和太行山东麓断裂带发生,与三条岩石圈走滑带吻合.第一种序列发生在上述三条走滑带之间,构成两个伸展区.构造样式的演化与烃源岩、油气藏和含油气系统的性质和分布有着密切的关系.

THE EVOLUTION OF THE PALEOGENE STRUCTURAL STYLES IN BOHAI GULF BASIN

Owing to the extension and strike slip action,there were five basic types of the structural styles during the Palaeogene in Bohai Gulf Basin.Non rotational graben,rotational half graben,rollover half graben and strike slip graben were major structural styles in Paleocene and early and middle Eocene.Rollover half graben,half graben and ramp sag were major in late Eocene and early Oligocene.Rollover half graben,half graben and ramp sag,strike slip graben were major in middle and late Oligocene.The evolution of the structural styles follows three orders including rotational half graben→rollover half graben→half graben and rap sag,non rotational graben→rollover half graben→half graben and ramp sag,and non rotational graben→strike slip graben.The orders with difference within each are controlled by the faults action in different areas.Later two orders take place along Tanlu fracture belt,Cangdong Lanliao fracture belt and Taihang east fracture belt which are three strike slip belts in the lithosphere.The first order occurs in two extensional areas between two strike slip belts.The evolution of structural styles have clo ser relations with the characters and distributions of the petroleum source rocks,the oil and gas pools,and the petroleum systems.