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A Martian Primary Magma. Olivine compositions in Martian meteorite Y-980459 indicate crystallization from a magma with a composition the same as bulk Y-980459. High-Pressure Experiments. Experimental apparatus and SEM image of an experimental run product. Experimental Results.
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A Martian Primary Magma Olivine compositions in Martian meteorite Y-980459 indicate crystallization from a magma with a composition the same as bulk Y-980459. COSMOCHEMISTRY iLLUSTRATED
High-Pressure Experiments Experimental apparatus and SEM image of an experimental run product. COSMOCHEMISTRY iLLUSTRATED
Experimental Results • Series of experiments allows construction of a phase diagram • The magma has both olivine and pyroxene on its liquidus at about 12 kbar (depth of 100 km in Mars) • Unless the amount of partial melting was extremely large, this is likely the pressure at which the magma formed COSMOCHEMISTRY iLLUSTRATED
The Martian Mantle • At multiple saturation, residual minerals have Mg# of 0.86 • This implies that the mantle source region for Y-098459 had this value if the amount of melting was very low • Consensus value for Martian mantle is Mg# of 0.75, implying very high % melting Options: - Martian mantle Mg# is > 0.75, - Martian mantle is heterogeneous - Y-098459 source was melted more than once COSMOCHEMISTRY iLLUSTRATED