Kaidun meteorite: A fragment of crystalline rock from a new parent body

Abstract

Two sections subsequently sawed from meteorite fragment Kaidun #d(4–5)C were examined under an optical and scanning electron microscope. The major minerals of the fragment are pigeonite and anorthite; the accessory minerals are spinels and occasional grains of ilmenite, Ca phosphate, and Fe sulfide. The compositions of the minerals broadly vary. The texture of the fragment, its mineralogy, and mineral chemistries definitely indicate that the fragment originated from a crystalline rock affected by partial melting during an impact event. The chemical compositions of both minerals (the concentration of the anorthite end member of plagioclase An99 and the Fe/Mn atomic ratio of 44 in the pyroxenes) differ from those in other known meteorite samples and suggest that fragment d(4–5)C of the Kaidun meteorite represents a new differentiated parent body that has never been sampled before.