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Sm and Gd isotopic shifts of Apollo 16 and 17 drill stem samples and their implications for regolith history
https://hiroshima.repo.nii.ac.jp/records/2006930
https://hiroshima.repo.nii.ac.jp/records/200693058281973-3fb6-4faf-b4cb-0f70cfd7f0ab
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
GCA_71-4_1074.pdf (1.1 MB)
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| Item type | デフォルトアイテムタイプ_（フル）(1) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 公開日 | 2023-03-18 | |||||||||
| タイトル | ||||||||||
| タイトル | Sm and Gd isotopic shifts of Apollo 16 and 17 drill stem samples and their implications for regolith history | |||||||||
| 言語 | en | |||||||||
| 作成者 |
Hidaka, Hiroshi
× Hidaka, Hiroshi
× Yoneda, Shigekazu
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| アクセス権 | ||||||||||
| アクセス権 | open access | |||||||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||||||
| 権利情報 | ||||||||||
| 権利情報 | Copyright (c) 2006 Elsevier Inc. | |||||||||
| 主題 | ||||||||||
| 主題Scheme | NDC | |||||||||
| 主題 | 450 | |||||||||
| 内容記述 | ||||||||||
| 内容記述 | The isotopic compositions of Sm and Gd in lunar regolith samples from the Apollo 16 and 17 deep drill stems showed clear isotopic shifts in 150Sm /149Sm (ε= +124 to +191 for A-16, and +37 to +111 for A-17) and 158Gd/157Gd (ε= +107 to +169 for A-16, and +31 to +84 for A-17) corresponding to neutron fluences of (5.68 to 9.03)x1016 ncm-2 for A-16 and (1.85 to 5.04)x1016 ncm-2 for A-17. The depth profiles of neutron fluences suggest that the regoliths at both sites were due to incomplete mixing of three different slabs which experienced individual two-stage irradiation before and after deposition of the upper slabs. The variations in REE compositions provide chemical evidence for incompletely vertical mixing of regoliths especially at upper layers of the two sites. The thermal neutron energy index estimated from the combination of Sm and Gd isotopic shifts, defined as εSm/εGd, shows a small variation (0.61-0.64) in the A- 16 core except for the surface layer. On the other hand, a large variation in εSm/εGd = 0.67 to 0.83 in the A-17 core may result from complicated history such as two-stage irradiation and incomplete mixing during the gardening processes. Isotopic enrichments of 152Gd and 154Gd correlated with Eu/Gd elemental abundances and neutron fluences were also observed in almost all of fifteen samples, showing evidence of neutron capture from 151Eu and 153Eu, respectively. | |||||||||
| 言語 | en | |||||||||
| 出版者 | ||||||||||
| 出版者 | Pergamon-Elsevier Science Ltd. | |||||||||
| 言語 | ||||||||||
| 言語 | eng | |||||||||
| 資源タイプ | ||||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||||||
| 資源タイプ | journal article | |||||||||
| 出版タイプ | ||||||||||
| 出版タイプ | AO | |||||||||
| 出版タイプResource | http://purl.org/coar/version/c_b1a7d7d4d402bcce | |||||||||
| 関連情報 | ||||||||||
| 識別子タイプ | DOI | |||||||||
| 関連識別子 | 10.1016/j.gca.2006.10.015 | |||||||||
| 関連情報 | ||||||||||
| 識別子タイプ | DOI | |||||||||
| 関連識別子 | http://dx.doi.org/10.1016/j.gca.2006.10.015 | |||||||||
| 収録物識別子 | ||||||||||
| 収録物識別子タイプ | ISSN | |||||||||
| 収録物識別子 | 0016-7037 | |||||||||
| 収録物識別子 | ||||||||||
| 収録物識別子タイプ | NCID | |||||||||
| 収録物識別子 | AA00655038 | |||||||||
| 開始ページ | ||||||||||
| 開始ページ | 1074 | |||||||||
| 書誌情報 |
Geochimica et Cosmochimica Acta Geochimica et Cosmochimica Acta 巻 71, 号 4, p. 1074-1086, 発行日 2007-02-15 |
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| 旧ID | 20656 | |||||||||
