Collaborative Research: Experimental Investigation of the Electrical Properties of Hydrous Silicate Melts in Subduction Context

Arizona State University, Scottsdale AZ

Investigators

Abstract

The dynamics and time-evolution of subduction are driven by mechanical and chemical processes that influence buoyancy forces, slab motion, contrasting thermal fields, phase equilibria, and volatile transport. By enhancing mass transfer and energy release, the cycle of fluids (and in particular, hydrous silicate melts) in subduction zones is a major component of slab recycling, arc volcanism, and continent-building processes. A better understanding of the role of melt and volatiles in subduction is therefore key to improving our knowledge of the structure and composition of subduction zones as well as geodynamic processes at work. It can also help us better assess volcanic and earthquake hazards in these contexts. This project is a multi-disciplinary and multi-scale investigation of the electrical conductivity of hydrous silicate melts in subduction context, at the depth of the mantle wedge and shallower, in order to characterize and model the electrical response of hydrous melts in subduction zones. In situ electrical measurements will be performed at pressure and temperature conditions relevant to subduction zones on dry and hydrous silicate melts. The major objective is to understand better the transport properties of melts and volatiles in subduction zones as imaged by geophysical (electromagnetic) surveys.