Cretaceous Tectonic Evolution of the Jiaolai Basin, North China

The Jiaolai Basin is a Cretaceous basin located in the Jiaodong Peninsula. Many important progresses concerning the sedimentary-tectonic evolution of the basin have been achieved, however, the paleotectonic stress field in the initial stage of the basin is still unclear. Based on the inversion of fault-slip data and analysis of conjugate shear joints and synsedimentary faults in the basin, we divide the Cretaceous tectonic evolution of the Jiaolai Basin into five stages according to the paleotectonic stress field: 1) NWW-SEE extension in the early Early Cretaceous, which controlled the initial deposition of the Laiyang Group; 2) near E-W slight compression in the late sedimentary period of the Laiyang Group; 3) E-W extension in the late Early Cretaceous; 4) NW-SE compression in the late Early Cretaceous, and 5) the extensional stress field between N-S to NNE-SSW in the Late Cretaceous under which the Wangshi Group were deposited. Abundant field geological phenomena and previous research results demonstrated that the NWW-SEE extensional stress field was prevalent in the initial stage of the basin. The NWW-SEE extension may ascribe to both roll-back of the Paleo-Pacific and post-orogeny of the Sulu orogenic belt. However, the change of extension direction during sedimentation of the Qingshan Group may indicate that the basin was mainly affected by the roll-back of the Paleo-Pacific. On the basis of the Cretaceous paleotectonic stress field analysis, we argue that the basin is a composite basin controlled by two processes, i.e., the Early Cretaceous rifting and the Late Cretaceous strike-slip pull-apart, respectively. © 2020, Science Press. All right reserved.