东濮凹陷拉张构造研究

A STUDY ON THE EXTENSIONAL STRUCTURES OF DONGPU SAG

本文认为东濮凹陷的拉张量是通过基底滑脱作用实现的，推断滑脱面深度在７～１２ｋｍ范围，滑脱受兰聊断裂正断与走滑双重构造性质控制。选取４条横贯东濮凹陷的地震反射剖面，用平衡横剖面原理计算验证了基底滑脱面深度，理论值与计算值较为符合。最后用平衡横剖面方法计算了这４条地震反射剖面的拉张量，凹陷中部拉张量最大，向北端逐渐减小。

In this paper, the authors study the extentional structures of Dongpu sag, and hold that it isthrough the hasal detachment that the amount of extension of Dongpu sag works. Thus, itinfers theoretically that the depth of detachment plane is under the control of the quality. ofdual structures of normal faults and strike slip, with scops in a depth of 7-12km approximately.In addition, the authors pick out four seismic reflection sections run across Dongpusag and calculate and verify the depth of detachment plane by the theory of the balancingacross section, finding out that the theoritical value is much in accordance with that calculated. Finally,the authors calculate the amount of estention of Dongpu sag on the four sectionsby using the balancing across section method, and show that the absolute extention variesfrom 13. 5 to 5. 2km, with the highest in the middle part of the sag, and gradually decreasingto the north end.