Large volcanic eruptions are mostly sourced above mobile basal mantle structures

Most deep mantle plumes rise from hot basal mantle structures, creating large volcanic eruptions at Earth’s surface. In previous studies, mantle plumes were the implicit process connecting volcanic eruptions to hot basal mantle structures. Here, we investigate the spatiotemporal links between volcanic eruptions, hot basal mantle structures, and explicitly modelled plume conduits from 300 million years ago. We consider three volcanic eruption databases, four tomographic models and six global mantle flow models. Through Monte Carlo significance testing we find a statistical-dependence relationship between modelled plume conduits and an eruption database containing both plume head and plume tail products. We show that these eruptions, if reconstructed above the exterior of basal mantle structures, are related to the edges of fixed basal mantle structures in one tomographic model, and to the edges of mobile basal mantle structures 1% to 1.6% denser than the surrounding mantle in mantle flow models.<p></p>