辽河盆地中央凸起南部海外河地区构造演化特征

Characteristics of structural evolution in Haiwaihe area， the southern part of the Central Salient in the Liaohe Basin

刘斐

摘要：根据走滑作用的强弱，将盆地内沉积分为后走滑层序、同走滑层序和前走滑层序。后走滑层序受走滑活动影响可以忽略，按照一般的平衡方法进行恢复；同走滑层序和前走滑程序可根据断层两侧厚度趋势分别给予补偿，使断层两侧断距经补偿恢复协调后按一般的平衡方法进行恢复。通过海外河地区走滑盆地定量平衡恢复，获得了该地区中-新生代构造演化过程的直观认识。从中生代开始伸展裂陷，新生代进一步张裂并发展成为大型的裂谷型盆地。沙河街组一段、二段沉积时期开始逐渐遭到NE向右行走滑改造，东营组沉积后盆地再次遭受较为强烈的剥蚀，基本结束了盆地的伸展裂陷历史。最后综合海外河地区石油地质特征，探讨了海外河地区油气成藏模式及下一步重点勘探研究方向。

Abstract: Sedimentary system in the Liaohe Basin could be divided into prestrikeslip sequence, synstrikeslip sequence, and poststrikeslip sequence according to the strength of strikeslip activities. The poststrikeslip sequence, which was slightly influenced by the strikeslip activities, could be restored by traditional methods of balanced crosssection. By contrast, the syn and pre strikeslip sequences, significantly controlled and influenced by the strikeslip activities, have to be restored with different thickness on both sides of the fault to balance the volume in twodimension. The quantitative balanced crosssection restoration of the strikeslip basin reveals the structural evolution process of the study area during the Mesozoic and Cenozoic. Balanced cross sections in Haiwaihe area show that the Liaohe Basin underwent progressively extension and depression during the Mesozoic, and evolved into a rift basin in the Cenozoic. The basin was modified by the NEtrending dextral strikeslip during the deposition of the first and second members of Shahejie Formation, and was uplifted and eroded again after the deposition of the Dongying Formation. Finally, based on a comprehensive analysis of the petroleum geological characteristics in Haiwaihe area, this paper discusses the model of hydrocarbon accumulation and prospects for exploration.

10.11743/ogg20110214