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Title: Ferric iron stabilization at deep magma ocean conditions
Fe2O3produced in a deep magma ocean in equilibrium with core-destined alloy sets the early redox budget and atmospheric composition of terrestrial planets. Previous experiments (≤28 gigapascals) and first-principles calculations indicate that a deep terrestrial magma ocean produces appreciable Fe3+but predict Fe3+/ΣFe ratios that conflict by an order of magnitude. We present Fe3+/ΣFe of glasses quenched from melts equilibrated with Fe alloy at 38 to 71 gigapascals, 3600 to 4400 kelvin, analyzed by synchrotron Mössbauer spectroscopy. These indicate Fe3+/ΣFe of 0.056 to 0.112 in a terrestrial magma ocean with mean alloy-silicate equilibration pressures of 28 to 53 gigapascals, producing sufficient Fe2O3to account for the modern bulk silicate Earth redox budget and surficial conditions near or more oxidizing than the iron-wüstite buffer, which would stabilize a primitive CO- and H2O-rich atmosphere.  more » « less
Award ID(s):
2153786 2317026 2016215
PAR ID:
10555676
Author(s) / Creator(s):
; ; ; ; ; ; ;
Publisher / Repository:
Science
Date Published:
Journal Name:
Science Advances
Volume:
10
Issue:
42
ISSN:
2375-2548
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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