First-principles

Abin; Abin; Dipta; Bijaya

Bulletin of ANPA

Abstract submitted to ANPA Conference July 14–16, 2023

Volume 5, Number 1

Condensed Matter Physics and Material Science

Abstract ID: ANPA2023-N00049

Abstract:

ANPA2023-N00049: First-principles molecular dynamics simulation and analysis of bulk Earth melt system: Insights into metal-silicate differentiation

Authors:

Abin shakya; School of Electrical Engineering and Computer Science, Louisiana State University, Baton Rouge, LA 70803, USA

Dipta Bhanu Ghosh; School of Electrical Engineering and Computer Science, Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA

Bijaya B Karki; School of Electrical Engineering and Computer Science, Department of Geology and Geophysics, Center for Computation and Technology, Louisiana State University, Baton Rouge, LA 70803, USA

To gain insights into the chemical evolution of Earth during its accretion phase, we use first-principles molecular dynamics to simulate a mixed metallic liquid-silicate magma ocean system. Our simulation considers a composition resembling that of the bulk Earth, comprising of four major elements: Fe, Mg, Si, and O in the amounts of 35.7, 19.0, 15.2, and 30.2 wt.%, respectively. We simulate the supercell containing Fe85Mg104Si72O251 under high pressure-temperature conditions (30-40 GPa and 3000-4000 K). By performing coordination/bonding and space-decomposition analyses along with interactive visualization of the atomic position-time series, we predict a chemical phase separation within the simulated melt system. This separation leads to the formation of an iron-rich region, corresponding to the metallic core, and an iron-poor region, corresponding to the silicate mantle. The estimated composition of the iron-rich phase consists of 89.0, 1.1, 4.8, and 5.1 wt.% of Fe, Mg, Si, and O, respectively. Conversely, the corresponding elemental proportions in the magma ocean phase are approximately 8.7, 29.2, 19.8, and 42.3 wt.%, resembling a pyrolytic mantle. Furthermore, we conduct simulations and analyses to examine the incorporation of two important volatile elements, H and N, within the metal-magma ocean system. Our preliminary analysis suggests that both elements exhibit a preference for partitioning into the liquid metal compared to the silicate magma ocean.

To cite this abstract, use the following reference: https://anpaglobal.org/conference/2023/ANPA2023-N00049