Multistage plate subduction controls intraplate volcanism and cratonic lithospheric thinning in Northeast Asia

Abstract

Although subduction is a critical factor impacting continental deformation, the interactions between deep dynamic processes and surface tectonic responses remain debated. Based on a systematic investigation of seismic tomography, plate reconstruction, and igneous rock data, we present a new model of continental co-deformation with a multistage subduction history involving the Proto-ocean, Izanagi, and Pacific plates in Northeast Asia. The high-resolution mantle seismic structures were ascertained using a novel global tomographic inversion based on adaptive inversion mesh refinement and regional velocity perturbation constraints from 298,725 hand-picked and > 16 million arrival times of multiple P-wave phases (e.g., P, pP (pwP), PP, PcP, Pdiff, PKP, PKiKP) which were recorded by the 4107 temporary and permanent stations in Northeast Asia. The unprecedented data reveal new integrative views on the geometry and behavior of mantle high-velocity anomalies associated with a sequence of oceanic lithosphere subduction events. The extensive compilation of dated volcanic samples provides strong constraints on past subduction events. Positions of remanent slabs derived from a multistage subduction history were reconstructed using the ages of initial subduction and slab sinking rates, where the geographical distribution of remnant slabs observed in our tomographic model helps to define the plate reconstruction history since the Early Mesozoic. The inferred multi-plate subduction configuration with slab advance, rollback, stagnation, break-off, and foundering, together with implied slab dehydration, should have resulted in various degrees of fluid-rock interactions among the slabs, the asthenosphere, and the continental lithosphere. We argue that the successive subduction processes of the slabs, intra-oceanic arc and ridge, and their associated fluids have played crucial roles in the intraplate volcanism and cratonic lithospheric thinning episodes in Northeast Asia. These new findings help elucidate the interaction and feedback between the evolution of the continental lithosphere and deep slab dynamics in Northeast Asia, exemplifying how the Earth's interior works.