Experimental Modeling of Formation of Native Metals (Fe, Ni, Co) in the Earth’s Crust by the Interaction of Hydrogen with Basaltic Melts

Abstract

In continuation of our early works, an experimental study of the kinetics and interaction mechanisms in the hydrogen-basalt melt system at a hydrogen pressure of 100 MPa and temperature of 1250°C carried out. It was found in kinetic experiments that, despite the high reduction potential of the H₂-melt system, the hydrogen oxidation reactions and the complete reduction of Fe oxides in the melt do not go to the end. As a result, initially homogeneous basalt melt becomes heterogeneous: H₂O is formed in the fluid phase; H₂O is dissolved in the basalt melts, and a small metal separation of the liquation structure formed at a temperature significantly lower than the melting temperature of the metal phases (Fe, FeNiCo alloy). The structure and dimensions of the experimentally established metal separations agree well with the natural data on the findings of small amounts of the metal phase, primarily iron and its alloys with nickel and cobalt, reported from magmatic rocks of various compositions and origins.