Mineralogical examination of the Yamato-79 achondrites : Polymict eucrites and ureilites
Mineralogical examination of the first one-third of the Yamato-79 achondrites collected by the JARE party in 1979 and 1980 seasons revealed that eight of them are polymict eucrites similar to the Antarctic polymict eucrites reported previously, and that Y-790727 is a howardite and Y-790981 is a urei...
| Main Authors: | , |
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| Format: | Report |
| Language: | English |
| Published: |
Mineralogical Institute, Faculty of Science, University of Tokyo
1982
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| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1382 http://id.nii.ac.jp/1291/00001382/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1382&item_no=1&attribute_id=18&file_no=1 |
| Summary: | Mineralogical examination of the first one-third of the Yamato-79 achondrites collected by the JARE party in 1979 and 1980 seasons revealed that eight of them are polymict eucrites similar to the Antarctic polymict eucrites reported previously, and that Y-790727 is a howardite and Y-790981 is a ureilite. The following Yamato-79 eucrites show features different from the known types. Y-790122 and Y-790266 are rich in lithic clasts. A thin section of Y-790122 consists of four different clast types joined together face to face with little matrix between them. Almost one-third of Y-790266 is a medium-grained subophitic basalt with pyroxene chemical zoning trends which simulate the host pigeonite and exsolved augite pair of the ordinary eucrites such as Juvinas. Y-790007 contains abundant cumulate eucrite clasts identical to Binda in their pyroxene exsolution texture and chemistry. |
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