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A series of 59 impacts in the laboratory reduced a coherent 460 g piece of the L6 ordinary chondrite ALH 85017 to a coarse-grained regolith. We then subjected the 125-250 m fines from this sample to reverberation shock stresses of 14.567 GPa in order to delineate the melting behavior of porous, unconsolidated, chondritic asteroid surfaces during meteorite impact. The initial pore space (40-50%) was completely closed at 14.5 GPa and a dense aggregate of interlocking grains resulted. Grain-boundary melting commenced at 80 GPa, which is associated with impact velocities >8 km/sec. The Fe-Ni and troilite clasts of the original meteorite melted with particular ease, forming immiscible melts that are finely disseminated throughout the silicate glass. These metal droplets are highly variable in size, extending to |
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