Abstract:

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.

Key words: Key words： strikeslip activity, balanced crosssection restoration, structural evolution, Haiwaihe area, Liaohe Basin