9628092 Hauri This project will begin a new generation of trace element partitioning experiments at the high pressures and temperatures applicable to magmatic conditions throughout the Earth's upper mantle and transition zone to the top of the lower mantle. The results will have important implications for the ancient and continuing differentiation of planetary interiors by partial melting and crystal fractionation. Synthesis experiments, including long-duration, time-series, and reversal experiments will be performed on the multi-anvil presses at the Geophysical Laboratory and at SUNY Stony Brook. The starting material will consist of a combination of natural rocks ranging from basalt to peridotite, with trace elements doped at 1000 ppm level where necessary. The trace element partition coefficients will be analyzed by ion probe at Woods Hole and the Department of Terrestrial Magnetism. Many elements will be examined simultaneously in individual experiments, focusing on about 20 key elements which are well determined in natural rocks (transition metals, REE, high-field-strength elements, alkalis and alkali-earth elements), provide potentially stringent tests of intramantle differentiation (e.g. pseudo-constant ratios Ce/Pb, Nb/U, Ba/Rb, K/U, etc.) and provide crucial links to the long-lived radioactive isotope systems (Rb/Sr, Sm/Nd, Lu/Hf, U/Pb, Th/Pb).
