Structure of the lithosphere and mesozoic sedimentary basins in western Liaoning, northern Liaoning, and Songliao, northeast China

The western Liaoning, northern Liaoning, and Songliao areas represent three different tectonic units with different lithospheric thermal-mechanical pr operties in terms of composition, thickness of the thermal lithosphere, eff ective elastic thickness, depth of the detachment surface, and strength of the lithosphere. Western Liaoning is characterized by a thick lithosphere w ith high rigidity and strength, whereas Songliao and northern Liaoning are characterized by relatively thin lithosphere with low rigidity and strength . These differences controlled the development of distinct types of basins under an extensional regime during the Early Cretaceous. The basins in west ern Liaoning are controlled by faulting rather than by thermal subsidence. The Songliao basin is controlled both by faulting and by thermal subsidence , and thus both syn- and post-rift sequences developed with the same thickn ess in the center of the basin. In contrast, in northern Liaoning, the basi ns are mainly controlled by faulting, and to a lesser extent by subsequent thermal subsidence. As a part of east China, where more than 93% of the pro ven oil reserves of China are distributed, the western Liaoning-northern Li aoning-Songliao area also has attracted considerable attention for its hydr ocarbon potential. The Songliao basin is proven to be the largest non-marin e petroliferous basin and one of the most important oil- and gas-producing basins in China. In addition, the Tieling-Changtu basin and the Zhezhong de pression in northern Liaoning show some petroleum potential. In contrast, b asins in western Liaoning represent a limited prospect for oil and gas.