Experimental partitioning of uranium between liquid iron sulfide and liquid silicate: Implications for radioactivity in the Earth's core

Measurable uranium (U) is found in metal sulfide liquids in equilibrium with molten silicate at conditions appropriate for a planetary magma ocean: 1-10 GPa, 1750-2100 degrees C, 0-28 wt% S, and fO(2) 2 log units below IW. However, the transfer of U from metal sulfide to silicate under our experimental conditions is so complete that insufficient U would remain so as to be of any importance to the core's heat budget. U content in the Sulfide phase increases strongly with S content but shows no significant variability with either pressure or temperature. Maximum D-U(sulfide/silicate) is 0.001 while most values are considerably lower. 2006 Elsevier Inc. All rights reserved.