Hydrocarbon exploration in the Dongying Sag is constrained by the development of many Cenozoic transtensional structures with complex patterns and dynamic mechanisms. This study uses seismic interpretation and analog modeling to investigate these transtensional structures. Significant results include dividing these transtensional structures into boundary fault, oblique rifting, and deep strike-slip fault controlled structures, according to the relationships between main and secondary faults. They developed in the steep slope zone, the central sag zone, and the slope zone, respectively. In profile, the transtensional structures formed appear to be semi-flower-like, step-like, or negative-flower-like. In plan-view, they appear to be broom-like, soft-linked, or en-echelon structures. Further, these transtensional structures are controlled by the oblique normal slip of boundary faults, by the oblique extension of sub-sags, and by the later extension of deep strike-slip faults. The geometric deformation of these transtensional structures is controlled by the angles between the regional extension direction and the strike of boundary faults, deep faults, or sub-sags, where a larger angle corresponds to less developed transtensional structures. Further, the transtensional structures in the Dongying Sag were created by multiphase and multi-directional extensions in the Cenozoic— which is also controlled by pre-existing structures. The strike of newborn secondary faults was determined by the regional extension direction and pre-existing structures.

东营凹陷新生代拉张构造发育较多，模式复杂，动力机制复杂，制约了油气勘探。本研究使用地震解释和模拟建模来研究这些转张结构。重要成果包括根据主、次断层关系将这些拉张构造分为边界断层、斜裂断层和深部走滑断层控制构造。分别发育于陡坡带、中央凹陷带和斜坡带。从侧面看，所形成的转张结构呈半花状、阶梯状或负花状。从平面图上看，它们呈扫帚状、软连接式或阶梯式结构。此外，这些拉张构造还受到边界断层的斜向正滑、洼陷的斜向延伸以及深部走滑断层的后期延伸的控制。这些拉张构造的几何变形受区域伸展方向与边界断层、深部断层或洼陷走向之间的夹角控制，夹角越大，拉张构造越不发育。此外，东营凹陷的拉张构造是新生代多期、多向伸展作用形成的，也是受先存构造控制的。新生次生断裂的走向由区域伸展方向和先存构造决定。