Effects of hydrogen on the electrical conductivity in upper mantle and transition zone minerals

Yale University, New Haven CT

Investigators

Abstract

The influence of water (hydrogen) on electrical conductivity in mantle Minerals will be investigated through high-pressure, temperature experiments. Samples investigated include olivine, orthopyroxene and garnet. The AC impedance will be determined for a range of 1 KHz to 1 MHz. In most cases, the investigators will determine the electrical conductivity in polycrystalline samples with controlled grain-size. All the samples are synthetic samples with controlled grain-size and water content. The synthesis will be made under controlled oxygen fugacity and oxide activity. In all runs, both grain-size and water content will be determined both before an after the experiment. The results will provide the functional relationships between electrical conductivity and temperature and water content (+ grain-size, oxygen fugacity). The results can be used to infer the water content in the Earth's upper mantle and transition zone. The PI will collaborate with Professor Utada's group at University of Tokyo, who investigates the three-dimensional distribution of electrical conductivity in Earth's upper mantle and transition zone in the western Pacific to infer the water distribution in this region of the Earth.