A Brachina-like inclusion in the Yamato-75097 L6 chondrite: A preliminary examination
A Brachina-like inclusion is identified in the Yamato-75097 L6 chondrite. The inclusion has a shiny black fusion crust and is relatively large (2.5×2.5×0.8cm) and about 15g in weight. The fusion crust is distinguished clearly from the dull black fusion crust of the host. Microscopically, the inclusi...
| Main Authors: | , , |
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| Format: | Report |
| Language: | English |
| Published: |
National Institute of Polar Research
1983
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| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1549 http://id.nii.ac.jp/1291/00001549/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1549&item_no=1&attribute_id=18&file_no=1 |
| Summary: | A Brachina-like inclusion is identified in the Yamato-75097 L6 chondrite. The inclusion has a shiny black fusion crust and is relatively large (2.5×2.5×0.8cm) and about 15g in weight. The fusion crust is distinguished clearly from the dull black fusion crust of the host. Microscopically, the inclusion has a fine-grained granular texture and consists mainly of olivine with minor merrillite and plagioclase, and a little chromite. Plagioclase is isotropic and presumably maskelynite. Pyroxene, nickel-iron and troilite were not identified. The texture of the inclusion appears to be similar to that of the Brachina meteorite. Compositions of the constituent minerals are olivine average Fo_<76> (range Fo_<75.0-76.5>, %M. D.=1.1), maskelynite An_<15>Ab_<75>Or_<10> and merrillite (MgO_<=3.62> FeO_<=0.48> CaO_<=44.9> Na_2O_<=2.79> P_2O_<5=47.4>). Olivine is compositionally homogeneous and relatively Mg-rich compared with that of Brachina. The olivine composition is very similar to that of the host. |
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