Research data for "Rift-Induced Repositioning of Mantle Plumes Beneath the Indian Lithosphere: Implications for Deccan Volcanism"

Preexisting continental rift system can modulate plume dynamics by altering the path of plume head in the upper mantle near lithosphere asthenosphere boundary (LAB). Our model simulations demonstrate that such plume-rift interaction is a function of plate velocity (Vp) and plume–rift distance (d) where small d (< 250 km) or high Vp (> 1cm/yr) conditions redirect a large portion of the plume materials towards the pre-existing rift system causing melting beneath the rift, whereas higher d or low Vp weakens the interaction, leaving the pre-existing rift zone as passive with little melting. We used our model results to understand how preexisting rift system in Indian craton reacted at the Cretaceous-Tertiary boundary during the Réunion plume’s encounter with the Indian plate, which eventually led to the 66 Ma Deccan volcanism. Rifts that were in close proximity (e.g., Narmada rift) deflected a significant amount of plume material towards the rift, causing significant underplating, subsequent melting, and reactivation of the rift system whereas rifts that were distant from the plume (e.g., Godavari rift) remained almost passive with much less melting.