Min Xu and Mike F. Middleton , School of Applied Geology, Curtin University of Technology, GPO Box U 1987, Perth, 6845 WA, Australia, phone: 61 8 92664459, fax: 61 8 9266 3153, [email protected]

The basins with different structural styles, sedimentary sequences and petroleum systems developed in the Western Liaoning, northern Liaoning and Songliao areas, forming a NE trending tectonic belt bound by deep faults.One of the representative basins in the western Liaoning area is the Fuxin basin, a NE-NNE trending fault basin that consists of an extension-related or syn-rifting supersequence. The structural style of the Songliao basin is characterized by the superimposition of the lower asymmetric fault basin and upper thermal subsidence. It is made up of syn-rifting and post-rifting supersequences with nearly the same ratio. The basins in the northern Liaoning area comprise a syn-rifting supersequence similar to that of the Fuxin basin and a post-rifting supersequence (less than 1 km) similar to the lower section of post-rifting supersequence in the Songliao basin.

The petroleum systems in the area can be classified into syn- and post-rifting petroleum systems related to the syn- and post-rift supersequences. The syn-rifting petroleum systems developing in the middle of the Songliao basin are the main gas-generating systems because the deeply buried source rocks were over-mature, whereas the post-rifting petroleum systems in the Songliao basin are the most important oil-generating systems. The syn-rifting petroleum system in the Fuxin basin is a limited petroleum system for the insufficient burial depth of the possible source rocks. But the source rock of syn-rifting petroleum system in the northern Liaoning area entered the "oil window" because of the further post-rifting subsidence.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia