40Ar-39Ar analyses of a lumar meteorite (Yamato-86032) and a few LL3 and LL4 chondrites from Antarctica
^<40>Ar-^<39>Ar analyses were performed for a lunar meteorite (Yamato-86032), two LL3 (Y-790448,Allan Hills-764) and one LL4 (Y-74442) chondrites from Antarctica. The lunar meteorite Y-86032 shows a scattered ^<40>Ar-^<39>Ar age spectrum with anomalously high ages in the high...
| Main Authors: | , |
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| Format: | Report |
| Language: | English |
| Published: |
Earthquake Research Institute, University of Tokyo/Institute for Study of Earth's Interior, Okayama University
1993
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| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=4603 http://id.nii.ac.jp/1291/00004603/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=4603&item_no=1&attribute_id=18&file_no=1 |
| Summary: | ^<40>Ar-^<39>Ar analyses were performed for a lunar meteorite (Yamato-86032), two LL3 (Y-790448,Allan Hills-764) and one LL4 (Y-74442) chondrites from Antarctica. The lunar meteorite Y-86032 shows a scattered ^<40>Ar-^<39>Ar age spectrum with anomalously high ages in the higher temperature fractions, indicating a shock effect on the analyzed sample. Among the three LL chondrites analyzed, the sample Y-790448 indicates a plateau ^<40>Ar-^<39>Ar age of 4521±28Ma in the lower temperature fractions (600-800℃). The other two LL chondrites show inverse staircase spectra in the higher temperature fractions. In the LL chondrite group, un-equilibrated chondrites seem to show older ^<40>Ar-^<39>Ar ages compared with equilibrated ones, which may be related to the differences in the thermal history of each portion of their parent body. |
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