Magnetotelluric Imaging of a Magma Plumbing System From the Asthenosphere to Crust Beneath the Newer Volcanic Province, Australia

Abstract The Newer Volcanic Province (NVP) in southeastern Australia is a classic example of continental intraplate volcanism located far from a plate boundary, yet the configuration of its magma plumbing system remains unclear. Using three‐dimensional (3D) magnetotelluric (MT) inversion, we imaged a vertically continuous, trans‐lithospheric conductive structure beneath the NVP. This structure consists of a sub‐horizontal zone in the asthenospheric mantle, interpreted as 0.1–1.0 vol.% carbonate‐rich melt, vertically linked to hydrous basaltic melt zones (2–5 vol.%) in the lithospheric mantle and shallow crust. These upper crust conductive zones likely represent remnant melt or metasomatic minerals. These features define a vertically integrated magma plumbing system from the asthenosphere to the surface. The geometry and depth of the anomalies are consistent with scenarios in which the carbonate‐rich melt may form in response to shear‐driven upwelling and edge‐driven convection. These observations provide new constraints on possible mantle processes that drive intraplate volcanism.