Abstract:

Stratigraphic repetation exists in deep-seated lower Cretaceous Series inthe southeast rise of the Songliao Basin.The acid volcanic rocks of the Yingcheng Formation intrude the Shahezi Formation instead of intercalation.This kind of intrusion can be seen on both surface profiles and seismic profiles in Santai,Guanmashan-Huihuiying areas in Jiutai County.The Yingcheng coal-measures as were called before is acturally the Shahezi Formation.It thus conclude that there was only Shahezi Formation in the study area in Early Cretaceous basining period which corresponds with the Aobao and Denglouku Formations in central depression.According to the above mentioned,the Aobao and Denglouku Formations may possibly be the most important deep-seated hydrocarbon source beds in the central depression of the Songliao Basin.