Molybdenum Valence in Basaltic Silicate Melts: Effects of Temperature and PressureThe metal-silicate partitioning behavior of molybdenum has been used as a test for equilibrium core formation hypotheses [for example, 1-6]. However, current models that apply experimental data to equilibrium core-mantle differentiation infer the oxidation state of molybdenum from solubility data or from multivariable coefficients from metal-silicate partitioning data [1,3,7]. Molybdenum, a multi-valent element with a valence transition near the fO2 of interest for core formation (approx.IW-2) will be sensitive to changes in fO2 of the system and silicate melt structure. In a silicate melt, Mo can occur in either 4+ or 6+ valence state, and Mo(6+) can be either octahedrally or tetrahedrally coordinated. Here we present X-ray absorption near edge structure (XANES) measurements of Mo valence in basaltic run products at a range of P, T, and fO2 and further quantify the valence transition of Mo.
Document ID
20110005566
Acquisition Source
Johnson Space Center
Document Type
Extended Abstract
Authors
Danielson, L. R. (Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Righter, K. (NASA Johnson Space Center Houston, TX, United States)
Newville, M. (Chicago Univ. Chicago, IL, United States)
Sutton, S. (Chicago Univ. Chicago, IL, United States)
Choi, Y. (Chicago Univ. Chicago, IL, United States)
Pando, K. (Jacobs Technologies Engineering Science Contract Group Houston, TX, United States)
Date Acquired
August 25, 2013
Publication Date
January 1, 2011
Subject Category
Geophysics
Report/Patent Number
JSC-CN-22824
Meeting Information
Meeting: 42nd Lunar and Planetary Science Conference