Early Cretaceous tectonostratigraphic evolution of the Erlian Basin, NE China: A record of Late Mesozoic intraplate deformation in East Asia

The Erlian Basin is one of the largest intracontinental Meso-Cenozoic basins in Northeast China. The basin is filled with extra-thick Cretaceous sediments and offers unique opportunities to untangle the Late Mesozoic intraplate deformation in East Asia. However, despite decades of petroleum exploration in the basin, the Early Cretaceous chronostratigraphy and structural evolution of the Erlian Basin have been poorly studied. Based on newly obtained zircon U-Pb geochronological data, well lithological logs, and seismic reflection profiles, the present study carries out a detailed analysis of the tectonostratigraphic evolution of the Erlian Basin during the Early Cretaceous. The depositional ages of the Lower Cretaceous strata in the basin are refined, and the Early Cretaceous evolution of the basin is reestablished. The Lower Aershan, Upper Aershan, Lower Tenggeer, Upper Tenggeer, and Saihan formations are constrained to the middle Valanginian (ca. 138-135 Ma), late Valanginian (ca. 135-133 Ma), Hauterivian-early Aptian (ca. 133-121 Ma), middle Aptian (ca. 119-115 Ma), and latest Aptian-Albian (post ca. 115 Ma), respectively. The Early Cretaceous syn-rift subsidence of the basin was intermittent rather than continuous, and was punctuated by multiphase contractional deformation during the earliest Cretaceous (prior to ca. 138 Ma), middle Valanginian (ca. 135 Ma), latest Valanginian (ca. 133 Ma), middle Aptian (ca. 120 Ma), late Aptian (ca. 115 Ma), and Early/Late Cretaceous boundary. We tentatively attribute the extensional and contractional deformation in the Erlian Basin to a series of continental collisions along Asian margins: Karakoram-Lhasa/Qiangtang collision, Kolyma-Omolon/Siberia collision, Siberia/Amuria collision, Chukotka/Kolyma-Omolon collision, West Philippines/South China collision, and Okhotomorsk/East Asia collision.