* Astronomy

Title: METAL AND SCHREIBERSITE IN MAYO BELWA, AN ENSTATITE ACHONDRITE
Authors: A.L. Graham

The Mayo Belwa meteorite (an aubrite) contains discrete metal grains ranging in size from less than 1 m to 300 m across, and schreibersites up to 25 m across. Intergrowths of metal and schreibersite also occur. These phases are distributed heterogeneously throughout the meteorite and are present both in the fine-grained matrix and within silicate crystals. The concentrations of the elements Ni, Fe, Si, Co, P, were determined in grains larger than 4 m across. Most metal grains have 1-8% Ni, the total range being 0.8-23.5% Ni. The 1-8% Ni metal may be sub-divided into two compositional groups, one relatively compact, having 1-3.8% Ni, 0.1-0.3% Si; the second having a much greater range in both Ni and Si (~4-12%, 0.1-1.2% respectively).

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