Imaging the Plumbing System of the Asymmetric Vavilov Spreading Ridge (Tyrrhenian Sea Back‐Arc Basin) From Combined Bathymetry and Magnetic Data

Abstract

Back-arc basins (BABs) are associated with plate margins where crustal shortening, seafloor spreading, and volcanism coexist. The Vavilov basin (Tyrrhenian Sea) is a Pliocene BAB associated with the Apennine-Tyrrhenian Sea subduction system and characterized by mantle exhumation. The NNE-SSW elongated Vavilov seamount represents the easternmost and younger spreading ridge of the Vavilov basin. Here we present results of a morphological and magnetic study of the Vavilov seamount. Our results show that the seamount represents the last stage of the eastward asymmetric opening of the BAB. Its plumbing system consists of a dike swarm emplaced during the reversed Matuyama epoch and a younger shallow reservoir feeding the central and eastern sectors during the normal Brunhes epoch. This evolution is associated with the progressive loading of the edifice due to lava flow emplacement. The asymmetry of the seamount mirrors the asymmetric opening of the Vavilov back-arc basin.