Handbook of Iron Meteorites (University of California Press, 1975).Īxon, H. Arizona's Meteorite Crater (American Meteorite Museum, Arizona, 1956). The origin of diamonds in ureilite meteorites is a timely topic in planetary geology as recent studies have proposed their formation at static pressures >20 GPa in a large planetary body, like diamonds formed deep within Earth’s mantle. Here we present the metallographic and X-ray diffraction data on which this conclusion is based. The shock event that produced these high pressure phases, therefore, must have taken place on its parent body or have been associated with the disruption of that body. It seems, therefore, that the diamond and lonsdaleite were present in the meteoroid before its final ablative passage through the atmosphere and soft landing on the ground. of Study of Diamonds in Meteorites Diamonds were first discovered in meteorites by. Virtually identical diamond–lonsdaleite-containing material in ALHA77283 occurs in a meteorite specimen with a well developed heat-altered zone produced by atmospheric ablation. (organic Compounds, Diamonds, Graphite) Gennadi Petrovich Vdovykin. The suggestion 7 that formation was by high gravitational pressure has not been accepted. ![]() The Canyon Diablo, Arizona, meteorite, the excavator of Meteor Crater, is the only other iron meteorite known to contain these high-pressure minerals, and their occurrence in that meteorite has been explained as the result of shock-induced transformation of graphite, most probably at the moment of terrestrial impact and disintegration of the projectile during crater formation 3–6. One of these, ALHA77283, contains troilite(FeS)–graphite(C)–schreibersite((Fe,Ni) 3P)–cohenite(Fe 3C) inclusions rich in the carbonado-type diamond–lonsdaleite ‘nodules’ previously described from the Canyon Diablo meteorite 1,2. Of the many meteorites recovered so far from the Allan Hills, Antarctica, only nine have been irons.
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