Jurassic-earliest Cretaceous tectonostratigraphic evolution of the Erlian Basin, Northeast China: Records of polyphase intracontinental deformation in Northeast Asia

摘要

The Erlian Basin is an important part of the late Mesozoic extensional basin system in Northeast Asia. The basin contains thick Jurassic-Lower Cretaceous rocks and provides excellent opportunities to understand intracontinental deformation in Northeast Asia during the late Mesozoic. However, the Jurassic-Early Cretaceous evolution of the basin and associated driving mechanisms remain disputed. Based on 13 new zircon U-Pb ages for the Jurassic-lowest Cretaceous strata in the Erlian Basin, the correlation of Jurassic-lowest Cretaceous strata between the Erlian Basin and the Yan Shan is reestablished and a high-precision chronostratigraphic framework is presented. The Aqitu-Qiha formations are ascribed to the Aalenian-early Bathonian (ca. 174-167 Ma), the Xing'anling Group to the Oxfordian-early Kimmeridgian (ca. 163-153 Ma), the Hugejiletu Formation to the Tithonian-early Valanginian (ca. 151-139 Ma), and the Aershan Formation to the Valanginian-? (= ca. 138 Ma). Combined with seismic reflection profiles, the Jurassic-earliest Cretaceous tectonostratigraphic evolution of the Erlian Basin is reconstructed and five major phases of deformation are revealed. These deformation phases include Aalenian-early Bathonian initial extension, late Bathonian-Callovian compression, Oxfordian-early Kimmeridgian extension, late Kimmeridgian-earliest Valanginian compression, and Valanginian extension. Integrated with geological evidences from peripheral regions of the Erlian Basin, potential driving mechanisms related to far-field tectonic events along Asian margins are suggested for each of these deformation phases.