THE FUNDAMENTAL GOAL OF THIS PROPOSAL IS TO PROVIDE EXPERIMENTAL DATA ON FE-ISOTOPE FRACTIONATION UNDER LUNAR MAGMATIC CONDITIONS. EXPERIMENTALLY DETERMINED FE-ISOTOPE FRACTIONATION FACTORS WILL PROVIDE A NEW METHOD FOR INVESTIGATING PLANETARY DIFFERENTIATION PROCESSES. THE PROPOSED RESEARCH IS MOTIVATED BY THE OBSERVED DICHOTOMY IN THE FE-ISOTOPE COMPOSITIONS OF LUNAR MARE BASALTS AND PREVIOUS ESTIMATES OF FE-ISOTOPE FRACTIONATION FACTORS BY NUCLEAR RESONANT INELASTIC X-RAY SCATTERING (NRIXS) SPECTROSCOPY. THIS PROPOSED WORK AIMS TO: (1) EXPERIMENTALLY DETERMINE THE FE-ISOTOPE FRACTIONATION FACTORS FOR ILMENITE AND OLIVINE CRYSTALLIZED FROM LUNAR MELT COMPOSITIONS AT LUNAR-RELEVANT OXYGEN FUGACITIES (FE2+ DOMINATED SYSTEMS) (2) FORWARD MODEL THE FE-ISOTOPE EVOLUTION DURING MAGMA OCEAN CRYSTALLIZATION AND MARE BASALT DIFFERENTIATION USING THE EXPERIMENTALLY CALIBRATED FRACTIONATION FACTORS. TO ACCOMPLISH THE TWO STATED RESEARCH OBJECTIVES THE PROPOSED WORK WILL CONSIST OF THREE TASKS: (1) ILMENITE CRYSTALLIZATION EXPERIMENTS (2) OLIVINE COOLING-RATE EXPERIMENTS AND (3) FE-ISOTOPE FRACTIONATION MODELING. EXPERIMENTS WILL BE CONDUCTED IN A ONE-ATMOSPHERE GAS-MIXING FURNACE AT WASHINGTON UNIVERSITY IN ST. LOUIS. MINERAL AND GLASS PHASES WILL BE SEPARATED FROM THE EXPERIMENTAL RUN PRODUCTS AND THE FE-ISOTOPE COMPOSITION OF EACH PHASE WILL BE MEASURED BY MCICP- MS IN THE ORIGINS LAB AT UNIVERSITY OF CHICAGO. THIS INTERDISCIPLINARY APPROACH TO DETERMINING FE-ISOTOPE FRACTIONATION FACTORS WILL EXPERIMENTALLY QUANTIFY THE ISOTOPIC EFFECT OF MINERAL FRACTIONATION FROM LUNAR BASALT COMPOSITIONS. THE DATA PRODUCED IN THE PROPOSED LABORATORY STUDY WILL IMMEDIATELY ENHANCE THE SCIENTIFIC RETURN OF THE APOLLO SAMPLE RETURN MISSIONS. ADDITIONALLY THE DATA WILL BE AVAILABLE FOR APPLICATION TO FUTURE APPLICATION TO THE EVOLUTION OF PLANETARY BODIES IN GENERAL. SPECIFICALLY THIS PROJECT ADDRESSES THE PLANETARY SCIENCE DIVISION SCIENCE GOAL IN CHAPTER 4.3 OF THE SMD 2014 SCIENCE PLAN TO ADVANCE THE UNDERSTANDING OF HOW THE CHEMICAL AND PHYSICAL PROCESSES IN THE SOLAR SYSTEM OPERATE INTERACT AND EVOLVE.