Jurassic to Early cretaceous sedimentary record: indications of Paleo-Pacific Plate subduction in Southeast China

Abstract

ABSTRACT Plate subduction plays a decisive role in continental tectonics, and subduction history is closely connected to deformation and sedimentation in the overriding plate. When and how the Paleo-Pacific Plate subducted beneath Southeast China in the Mesozoic is debated. Here, we show that provenance data, including detrital composition point counts, palaeocurrent data, and detrital zircon U-Pb geochronology from basins in Southeast China, record the timing and process of Paleo-Pacific Plate subduction during the Jurassic and Earliest Cretaceous. The U-Pb dating of detrital zircons from Jurassic samples indicates that the sediments were transported from multiple sources, including intracratonic mountains, tectonic belts and the inferred active continental margin arc that resulted from Paleo-Pacific Plate subduction. The clastic composition and U-Pb dating of Early Cretaceous tuffs suggest that they were sourced from nearby magmatic rocks and the eastern inferred magmatic arc. Based on detrital zircon U-Pb dating, igneous rock isotope, sedimentary, and structural data, we infer that an active continental magmatic arc developed along the coast of Southeast China in the Early Jurassic to Early Cretaceous (~200 Ma-135 Ma). The westward subduction of the Paleo-Pacific Plate initiated in the Early Jurassic (~200 Ma) and continued to the Early Cretaceous (~135 Ma). Paleo-Pacific Plate subduction resulted in the uplift of the northern Wuyi Mountain region and eastern South China and controlled the provenance characteristics of the sedimentary basins in Southeast China during the Jurassic to Early Cretaceous.