Linking Intraplate Volcanism to Lithospheric Structure and Asthenospheric Flow

Abstract Several of Earth's intraplate volcanic provinces are hard to reconcile with the mantle plume hypothesis. Instead, they exhibit characteristics that more compatible shallower processes involve interplay between uppermost flow and base heterogeneous lithosphere. The mechanisms most commonly invoked edge‐driven convection (EDC) shear‐driven upwelling (SDU), both which act focus associated decompression melting adjacent steps in lithospheric thickness. In this study, we undertake a systematic numerical investigation, 2‐D 3‐D, quantify sensitivity EDC, SDU, key controlling parameters. Our simulations demonstrate spatio‐temporal EDC sensitive geometry material properties step, addition magnitude depth‐dependence upper‐mantle viscosity. These also indicate asthenospheric shear can either enhance or reduce velocities melting, depending upon orientation relative step. When combined, such sensitivities explain why step changes thickness, common along cratonic edges passive margins, only produce volcanism at isolated points space time. predicted trends melt production suggest that, absence potential interactions plumes, SDU viable for shorter‐lived, lower‐volume provinces.