Related Experiment Video
Updated: Oct 4, 2025

Simulation of the Planetary Interior Differentiation Processes in the Laboratory
Published on: November 15, 2013
Stratification in planetary cores by liquid immiscibility in Fe-S-H
Shunpei Yokoo1, Kei Hirose2,3, Shoh Tagawa2,3
1Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan. shunpei@eps.s.u-tokyo.ac.jp.
Abstract:
Liquid-liquid immiscibility has been widely observed in iron alloy systems at ambient pressure and is important for the structure and dynamics in iron cores of rocky planets. While such previously known liquid immiscibility has been demonstrated to disappear at relatively low pressures, here we report immiscible S(±Si,O)-rich liquid and H(±C)-rich liquid above ~20 GPa, corresponding to conditions of the Martian core. Mars' cosmochemically estimated core composition is likely in the miscibility gap, and the separation of two immiscible liquids could have driven core convection and stable stratification, which explains the formation and termination of the Martian planetary magnetic field. In addition, we observed liquid immiscibility in Fe-S-H(±Si,O,C) at least to 118 GPa, suggesting that it can occur in the Earth's topmost outer core and form a low-velocity layer below the core-mantle boundary.
More Related Videos
11:50Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
08:02Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography
Published on: February 25, 2015
Related Concept Videos
Phase Transitions: Sublimation and Deposition
Phase Diagram
Equation of State
Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Phase Transitions: Melting and Freezing
Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....