Abstract Rifting is a tectonic process that leads to extensive magmatic activity, continental breakup, and the formation of new oceanic crust. The interplay between rifting and dynamic mantle flow driven by thermal heterogeneity in the mantle along the rift‐axis can influence magmatism and deformation beyond the rift zone. We constructed a series of three‐dimensional geodynamic models to simulate mantle flow during the syn‐ and post‐rift phases by integrating different initial temperature conditions for the extending rift zone and rift process zone (RPZ). We define the RPZ as the region beyond the rift‐tip where strain‐rates are elevated relative to the surroundings, enabling potential rift propagation. Our study demonstrated that rift‐induced mantle flow, derived from a model with a higher initial temperature (+100K), channelized into the RPZ, reaching up to approximately 900 km beyond the rift‐tip. Even after rift termination, the channelized mantle flow continued to transport melt and heat, maintaining a melt flux of approximately 6 × 10 16 kg/Myr toward the cold and thick lithospheric mantle. Thermal instability induced by the channelized mantle caused localized lithospheric erosion and mantle upwelling. Our study demonstrates that the channelized flow provides new insights into geodynamic evolution, encompassing rift propagation and magma supply to intraplate volcanism. The persistent transport of heat and mass to the RPZ beyond the rift‐tip, even after rift termination, can contribute to both accretion and erosion of cold continental roots.
Jang et al. (Mon,) studied this question.