Slab Subduction and Pull Link Magmatism at Active and Passive Continental Margins

Abstract

Subduction leads to voluminous arc magmatism at active continental margins; however, the potential far-field geodynamic connections with coeval magmatism along opposing passive margins, are rarely investigated. Here we report large-scale and parallel mafic dike swarms on the South Qinling passive margin, whose geochemical features record the thick and cold subcontinental lithospheric mantle beneath passive margin was gradually replaced by thin and hot one during the early Paleozoic. The subduction of the Proto-Tethys oceanic lithosphere led to arc magmatism along the active margin, shortly after the rift-related mafic dike swarms occurred along the passive margin. Subsequent to the continuous oceanic subduction including the ridge-margin collision, mantle upwelling and slab rollback eventually triggered large-scale rift-related magmatism and the opening of new ocean basin at passive margin, and also back-arc magmatism on the active margin. We highlight slab subduction and pull link the geodynamic processes at active and passive continental margins, which improves our understanding of plate tectonics.