Inference of a plume conduit in and around the LaRéunion Island from 3D Migration of Ps conversionsfrom the Mantle Transition Zone

The La Réunion hotspot is one of the best examples of a primary plume, manifested as intraplate volcanism, a linear chain of volcanos with age progression, a large igneous province and geochemical anomaly. In this study, we investigate the mantle transition zone structure in and around the La Réunion Island using 3D migration of P-Receiver functions to decipher the effect of the plume on the Mantle Transition Zone(MTZ) and its architecture. Results indicate a thin MTZ beneath Madagascar, its western side, the eastern and south-eastern side of La Réunion sampling the oceanic region, in terms of a depressed 410 km and elevated 660 km discontinuity. A thin MTZ suggests high-temperature anomalies within, caused by the plume. Interestingly, we detect a depressed 410 km discontinuity exactly beneath the La Réunion hotspot and a broader depression of the 660 km discontinuity in and around it. These maiden results shed light on the high-temperature anomalies in the mid mantle, probably sourced from the La Réunion plume and provide evidence for Majorite-garnet (Mj) to Perovskite (Pv) phase transformation at the 660 km discontinuity. We postulate that the conduit of the La Réunion plume has initially hit the 660 km discontinuity and got horizontally spread at this depth and further progressed to the 410 km discontinuity as a columnar structure.