Cryptic Magma Chamber in the Deccan Traps Imaged Using Receiver Functions and Surface Wave Dispersion

Abstract

AbstractAn anomalous crust and lithospheric mantle in the Deccan Volcanic Province are imaged below a 160 km long W‐E profile through the joint inversion of receiver functions and surface wave dispersion. The upper crust has an unusually low S‐wave velocity (Vs ∼ 3.3–3.5 km/s) at 8–17 km depth, underlying a 4 km thick high‐velocity layer (Vs > 3.8 km/s). The low velocity possibly represents the frozen magma reservoir, the source for the magma eruption at ∼65 Ma due to the interaction of the Reunion plume with India. The shallow, high‐velocity layer could be basaltic mafic intrusions responsible for the production of massive CO2 degassing. The Moho deepens beneath the west coast to ∼45 km due to 10–15 km of magma underplating. The mantle plume scar is seen as thinned lithosphere (80–100 km), with the presence of long‐lived low‐velocity layers in the shallow mantle attributed to the presence of sulfide melts.