Mineralogical study of the ALH-77283 iron meteorite
Of the many meteorites recovered so far from the Yamato Mountains and Victoria Land, Antarctica, only twenty-four have been irons. One of these, Allan Hills-77283,type IA coarse octahedrite, contains diamond-lonsdaleite nodules, for which extraterrestrial shock origin has been proposed. The shock te...
Summary: | Of the many meteorites recovered so far from the Yamato Mountains and Victoria Land, Antarctica, only twenty-four have been irons. One of these, Allan Hills-77283,type IA coarse octahedrite, contains diamond-lonsdaleite nodules, for which extraterrestrial shock origin has been proposed. The shock textures of ALH-77283,52 have been studied by metallographic, X-ray and electron diffraction, and analytical SEM techniques. The shock pressure and temperature were estimated to be about 600-750 kb and 400-500℃ from the shock-hatched and recrystallized kamacites in comparison with the standard scale produced by the shock-loaded experiments on the Odessa iron meteorite (HEYMANN et al. : J. Geophys. Res., 71,619,1966; M. E. LIPSCHUTZ : Geochim. Cosmochim. Acta, 31,621,1967). |
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