Geochemistry and origin of metal,olivine clasts,and matrix in the Dong Ujimqin Qi mesosiderite |
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| Authors: | Ping Kong Wen Su Xianhua Li Bernhard Spettel Herbert Palme Kejie Tao |
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| Institution: | 1. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, P.O. Box 9825, Beijing 100029, China;2. Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China;3. Max‐Planck‐Institut für Chemie, P.O. Box 3060, D‐55020 Mainz, Germany;4. Institut für Geologie und Mineralogie, Univerist?t zu K?ln, 50674 K?ln, Germany |
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| Abstract: | Abstract— The Dong Ujimqin Qi mesosiderite is the first recorded fall of a stony‐iron meteorite in China. According to silicate textures and metal composition, this meteorite is classified as a member of subgroup IB. Instrumental neutron activation analyses (INAA) of metals show that the matrix metal has lower concentrations of Os, Ir, Re, and Pt, but higher concentrations of Ni and Au than the 7.5 cm metal nodule present in the meteorite. We attribute these compositional differences to fractional crystallization of molten metal. Studies of olivine clasts show that FeO contents are uniform in individual olivine crystals but are variable for different olivine clasts. Although concentrations of rare earth elements (REEs) change within olivine clasts, they all exhibit a vee‐shaped pattern relative to CI chondrites. The relatively high concentrations of REEs in olivine and the shape of REE patterns require a liquid high in REEs and especially in light REEs. As such a liquid was absent from the region where basaltic and gabbroic clasts formed, mesosiderite olivine must have formed in a part of the differentiated asteroid that is different from the location where other mesosiderite silicate clasts formed. |
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