Construction of Earth formation model by isotopic analysis of siderophile elements in meteorites and Archean igneous rocks

2022 Fiscal Year Annual Research Report

• Project/Area Number: 19H00715
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: 横山 哲也 東京工業大学, 理学院, 教授 (00467028)
• Co-Investigator(Kenkyū-buntansha): 石川 晃 東京工業大学, 理学院, 准教授 (20524507) ; 玄田 英典 東京工業大学, 地球生命研究所, 教授 (90456260)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 親鉄元素 / 同位体異常 / 地球形成モデル / 太古代火成岩 / 隕石

Outline of Annual Research Achievements

・ダブルスパイク法によるMo安定同位体分別の測定を更に改良し最適化を行った。種々の地球試料に適用したところ、±0.05δでの分析を実現し、隕石に適用する準備が整った。
・核合成起源同位体異常については、メソシデライトおよび未分類エイコンドライト、NWA6693・6704の分析を実施した。メソシデライトはNC的Mo同位体組成を持ち、NCでも比較的大きなε94Mo＝1という異常を持つことが分かった。これはメソシデライト母天体（小惑星ベスタ）の形成時期に、NC領域が大きなMo同位体異常を保持していたことを意味する。また、NWA6693・6704のMo同位体組成はCC的であることが初めて分かった。NCよりも冷たく惑星形成が遅かったとされるCC領域において、どのようにして天体の溶融が起きたのか。地球形成へのCC物質の影響も含め、今後も研究を継続する。
・地球史試料については、オーストラリアおよび南アフリカのコマチアイト（33－27億年前）の分析および比較を行い、古いコマチアイトほど強親鉄元素濃度が低くなる傾向があること、ならびに同時代のコマチアイトでも含まれる強親鉄元素濃度に明らかな差異があることの２点が判明した。地球マントルの強親鉄元素濃度進化が集積の結果を反映していると考えた場合、マントルが均質化するプロセスは地域的にバリエーションがあり、不均質に進行したことを示唆している。
・理論研究では、地球集積に関するモデルを発表した。従来、木星の早期形成でNC天体とCC天体は離れた場所で形成され、その後Late AccretionによりCC物質が地球に降り注いだと考えられてきたが、本研究により、地球形成の初期段階からNC物質に10%程度のCC物質が寄与し、一体的に地球を形成したということが分かった。このことが、太古代試料にMo同位体異常が見られないことの本質的原因であると、結論付けられる。

Research Progress Status

令和4年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和4年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Strontium isotope evidence for the repeated formation of refractory inclusions in the Allende meteorite (2023)
  • Author(s): Masuda, Y., Yokoyama, T.
  • Journal Title: Geochimica et Cosmochimica Acta Volume: 345 Pages: 50-61
  • DOI: 10.1016/j.gca.2023.01.024
  • Peer Reviewed
• [Journal Article] Evaluation of the Residual Mass Fractionation in High‐Precision Cr Isotopic Analysis with TIMS (2023)
  • Author(s): Yokoyama, T., Ohkuma, Y., Nishikawa, K., Sumiya, K., Gautam, I.
  • Journal Title: Geostandards and Geoanalytical Research Volume: ー Pages: ー
  • DOI: 10.1111/ggr.12479
  • Peer Reviewed
• [Journal Article] Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites (2023)
  • Author(s): Yokoyama, T., Nagashima, K. et al.
  • Journal Title: Science Volume: 379 Pages: eabn7850
  • DOI: 10.1126/science.abn7850
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Water Delivery to Terrestrial Planet Regions during the Stages of Jupiter’s Formation and Migration in the Grand Tack Model (2023)
  • Author(s): Ogihara Masahiro、Genda Hidenori、Sekine Yasuhito
  • Journal Title: The Planetary Science Journal Volume: 4 Pages: 32～32
  • DOI: 10.3847/PSJ/acb64b
  • Peer Reviewed / Open Access
• [Journal Article] Oxygen isotopes of anhydrous primary minerals show kinship between asteroid Ryugu and comet 81P/Wild2 (2022)
  • Author(s): Kawasaki, N., Nagashima, K., et al.
  • Journal Title: Science Advances Volume: 8 Pages: eade2067
  • DOI: 10.1126/sciadv.ade2067
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis (2022)
  • Author(s): Paquet, M., Moynier, F., Yokoyama, T., et al.
  • Journal Title: Nature Astronomy Volume: 7 Pages: 182-189
  • DOI: 10.1038/s41550-022-01846-1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Solar System calcium isotopic composition inferred from Ryugu samples (2022)
  • Author(s): Moynier F., Dai W., Yokoyama T., et al.
  • Journal Title: Geochemical Perspectives Letters Volume: 24 Pages: 1~6
  • DOI: 10.7185/geochemlet.2238
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Ryugu’s nucleosynthetic heritage from the outskirts of the Solar System (2022)
  • Author(s): Hopp, T., Dauphas, N. et al.
  • Journal Title: Science Advances Volume: 8 Pages: eadd8141
  • DOI: 10.1126/sciadv.add8141
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Presolar Stardust in Asteroid Ryugu (2022)
  • Author(s): Barosch, J, Nittler, L.R., et al.
  • Journal Title: The Astrophysical Journal Letters Volume: 935 Pages: L3
  • DOI: 10.3847/2041-8213/ac83bd
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Geochemical records of the end-Triassic Crisis preserved in a deep marine section of the Budva Basin, Dinarides, Montenegro. (2022)
  • Author(s): de Graaff Sietze J.、Percival Lawrence M.E.、Kaskes Pim、Dehais Thomas、de Winter Niels J.、Jansen Max N.、Smit Jan、Sinnesael Matthias、Vellekoop Johan、Sato Honami、Ishikawa Akira、Spassov Simo、Claeys Philippe、Goderis Steven
  • Journal Title: Palaeogeography, Palaeoclimatology, Palaeoecology Volume: 606 Pages: 111250～111250
  • DOI: 10.1016/j.palaeo.2022.111250
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Sulfur in Archean komatiite implies early subduction of oceanic lithosphere (2022)
  • Author(s): Kubota Yusuke、Matsu'ura Fumihiro、Shimizu Kenji、Ishikawa Akira、Ueno Yuichiro
  • Journal Title: Earth and Planetary Science Letters Volume: 598 Pages: 117826～117826
  • DOI: 10.1016/j.epsl.2022.117826
  • Peer Reviewed
• [Journal Article] Rock and sediment dataset of petit-spots in the northwestern Pacific (2022)
  • Author(s): Akizawa Norikatsu、Hirano Naoto、Machida Shiki、Ishikawa Akira、Niwa Yuka、Shimoda Gen、Yasukawa Kazutaka、Matsuzaki Kenji M.、Tamura Chiori、Kaneko Junji
  • Journal Title: Data in Brief Volume: 45 Pages: 108764～108764
  • DOI: 10.1016/j.dib.2022.108764
  • Peer Reviewed
• [Presentation] The Ryugu Reference Powder (RRP): A consortium study of elemental and isotopic solar system abundances. (2023)
  • Author(s): Yokoyama, T., Dauphas, N., Fukai, R., Usui, T., Tachibana, S., Schoenbaechler, M., Busemann, H., Abe, M., Yada, T.
  • Organizer: Lunar and Planetary Science Conference, The Woodlands, USA.
  • Int'l Joint Research
• [Presentation] Nickel isotopic composition of Ryugu samples returned by the Hayabusa2 mission. (2023)
  • Author(s): Spitzer, F., Burkhardt, C., Kleine, T., …, Yokoyama, T., et al.
  • Organizer: Lunar and Planetary Science Conference, The Woodlands, USA.
  • Int'l Joint Research
• [Presentation] An exploration of hydrogen content in magnetite from asteroid Ryugu. (2023)
  • Author(s): Aleon, J., Mostefaoui, S., Bureau, H., Vangu, D., Khodja, H., …, Yokoyama, T., et al.
  • Organizer: Lunar and Planetary Science Conference, The Woodlands, USA.
  • Int'l Joint Research
• [Presentation] High precision sims oxygen isotope analyses of carbonates in Ryugu. (2023)
  • Author(s): Kita, K. N., Kitajima, T., Kawasaki, N., Nagashima, K., Sakamoto, N., Yurimoto, H., …, Yokoyama, T., et al.
  • Organizer: Lunar and Planetary Science Conference, The Woodlands, USA.
  • Int'l Joint Research
• [Presentation] Samarium and neodymium isotopic compositions of C-type asteroid (162173) Ryugu. (2023)
  • Author(s): Z. A. Torrano, Z. A., Jordan, M. K., Mock, T. D., Carlson, R. W., Yokoyama, T., Gautam, I., et al.
  • Organizer: Lunar and Planetary Science Conference, The Woodlands, USA.
  • Int'l Joint Research
• [Presentation] Radiogenic, nucleosynthetic, and stable isotope variations in strontium in samples returned by Hayabusa2 of Cb-type asteroid Ryugu. (2023)
  • Author(s): Wadhwa, M., Y. Masuda, Y., Rai, V. K., I. Gautam, I., Haba, M. K., Yokoyama, T., Hines, R., et al.
  • Organizer: Lunar and Planetary Science Conference, The Woodlands, USA.
  • Int'l Joint Research
• [Presentation] Molybdenum isotopic compositions in igneous rocks from Izu arc. (2023)
  • Author(s): Tamura, T., Yokoyama, T., Kuritani, T., Ishikawa, A., Gautam, I.
  • Organizer: IAVCEI 2023, Rotorua, New Zealand.
  • Int'l Joint Research
• [Presentation] アルカリ融解法によるコンドライト中のCrおよびTi同位体組成の決定 (2022)
  • Author(s): 大熊悠介、 横山哲也、 飯塚毅、 増田雄樹
  • Organizer: 同位体比部会2022, 箱根
• [Presentation] Chemical abundances in Ryugu, nugget effect, and cosmic composition. (2022)
  • Author(s): Dauphas, N., Yokoyama, T., Fukai, R., Usui, T., Tachibana, S., Schoenbaechler, M., Davis, A. M., Yurimoto, H., et al.
  • Organizer: Hayabusa Symposium 2022, Sagamihara, Kanagawa.
  • Int'l Joint Research
• [Presentation] Oxygen and carbon isotope compositions of Ryugu’s carbonates: Constraints on the conditions of aqueous alteration. (2022)
  • Author(s): Fujiya, W., Kawasaki, N., Nagashima, K., Alexander, C. M. O’D., Yurimoto, H., … Yokoyama, T., et al.
  • Organizer: Hayabusa Symposium 2022, Sagamihara, Kanagawa.
  • Int'l Joint Research
• [Presentation] Oxygen isotope analyses of magnetite in Ryugu. (2022)
  • Author(s): Kita, K. N., Kitajima, T., Nagashima, K., Kawasaki, N., Sakamoto, N., Yurimoto, H., …, Yokoyama, T., et al.
  • Organizer: Hayabusa Symposium 2022, Sagamihara, Kanagawa.
  • Int'l Joint Research
• [Presentation] Zinc, copper and calcium isotopic composition of Ryugu’s samples. (2022)
  • Author(s): Moynier, F., Paquet, M., Dai, W., Yokoyama, T., Hu, Y., et al.
  • Organizer: Hayabusa Symposium 2022, Sagamihara, Kanagawa.
  • Int'l Joint Research
• [Presentation] Distinct ages and temperatures of aqueous activities recorded in Ryugu samples. (2022)
  • Author(s): Nagashima, K., Kawasaki, N., Sakamoto, N., Fujiya, W., Yurimoto, H., …, Yokoyama, T., et al.
  • Organizer: Hayabusa Symposium 2022, Sagamihara, Kanagawa.
  • Int'l Joint Research
• [Presentation] Molybdenum and Osmium isotopic compositions of Ryugu sample. (2022)
  • Author(s): Nakanishi, N., Ishikawa, A., Yokoyama, T., Walker, R.J.
  • Organizer: Hayabusa Symposium 2022, Sagamihara, Kanagawa.
  • Int'l Joint Research
• [Presentation] 隕石の精密同位体分析に基づく銀河系化学進化とr核種の起源 (2022)
  • Author(s): 横山哲也
  • Organizer: 天の川銀河研究会2022, 鹿児島大学
• [Presentation] 元素の起源と地球化学 (2022)
  • Author(s): 横山哲也
  • Organizer: 放射化学討論会2022, 東京大学
  • Invited
• [Presentation] 神津島の流紋岩及び玄武岩質捕獲岩のMo安定同位体組成 (2022)
  • Author(s): 田村達也、横山哲也、石川晃
  • Organizer: 日本地球化学会2022年会, 高知大学
• [Presentation] アエンデ隕石細粒CAIの核合成起源Ti同位体異常 (2022)
  • Author(s): 増田雄樹、横山哲也、飯塚毅、日比谷由紀
  • Organizer: 日本地球化学会2022年会, 高知大学
• [Presentation] 火星隕石のクロム同位体組成 (2022)
  • Author(s): 西川慶次、横山哲也
  • Organizer: 日本地球化学会2022年会, 高知大学
• [Presentation] Hydrogen isotopic composition of water in Ryugu samples returned by the Hayabusa2 mission. (2022)
  • Author(s): Piani, L., Marrocchi1, Y., Nagashima, K., Kawasaki, N., Sakamoto, N, Bajo, K., Yokoyama, T., et al.
  • Organizer: MetSoc, Glasgow, UK.
  • Int'l Joint Research
• [Presentation] Nickel isotopic composition of Ryugu samples returned by the Hayabusa2 mission. (2022)
  • Author(s): Spitzer, F., Burkhardt, C., Kleine, T., …, Yokoyama, T., et al.
  • Organizer: MetSoc, Glasgow, UK.
  • Int'l Joint Research
• [Presentation] Presolar C- and O-rich grains in the matrix and a clast in asteroid Ryugu. (2022)
  • Author(s): Nguyen, A. N., Mane, P., Piani, L., …, Yokoyama, T., et al.
  • Organizer: MetSoc, Glasgow, UK.
  • Int'l Joint Research
• [Presentation] Cr and Ti isotope systematics of Ryugu samples. (2022)
  • Author(s): Yokoyama, T., et al.
  • Organizer: Goldschmidt Conference, Hawaii, USA.
  • Int'l Joint Research
• [Presentation] Pb isotopic compositions of Ryugu samples and carbonaceous chondrites. (2022)
  • Author(s): Haba, M.K., Yokoyama, T., et al.
  • Organizer: Goldschmidt Conference, Hawaii, USA.
  • Int'l Joint Research
• [Presentation] Distribution of rare-earth elements in fine-grained Calcium and Aluminum-rich inclusions from Allende meteorite. (2022)
  • Author(s): Masuda, Y., Niki, S., Yokoyama, T., Hirata, T.
  • Organizer: Goldschmidt Conference, Hawaii, USA.
  • Int'l Joint Research
• [Presentation] 5-stage multielement separation procedure: A unique and essential tool for the multi-isotopic analyses of precious (< 30 mg) meteorites and asteroidal materials. (2022)
  • Author(s): Gautam, I., Yokoyama, T., Ohkuma, Y., Iizuka, T., Horan, M.F., Carlson, R.W.
  • Organizer: Goldschmidt Conference, Hawaii, USA.
  • Int'l Joint Research
• [Presentation] Simple and accurate determination of chalcophile and highly siderophile elements in carbonaceous chondrites using triple quadrupole ICP-MS. (2022)
  • Author(s): Ishikawa, A., Nakano,S., Fujita, R., Yokoyama, T.
  • Organizer: Goldschmidt Conference, Hawaii, USA.
  • Int'l Joint Research
• [Presentation] The isotopic variations in bulk-scale carbonaceous chondrites and the possible targets in the next sample return mission. (2022)
  • Author(s): Fukai, R., Yokoyama, T., Arakawa, S., Homma, K., Okuzumi, S., Shimaki, Y.
  • Organizer: Goldschmidt Conference, Hawaii, USA.
  • Int'l Joint Research
• [Presentation] Recent progress on the application of nucleosynthetic isotope anomalies in meteorites to elucidate the origin of r-process nuclides. (2022)
  • Author(s): Yokoyama, T., Tsujimoto, T., Fukai, R.
  • Organizer: JpGU 2022, 幕張
  • Invited
• [Presentation] 地球外物質の精密Cr同位体測定法の開発 (2022)
  • Author(s): 横山 哲也、住谷 格生、大熊 悠介、西川 慶次
  • Organizer: JpGU 2022, 幕張
• [Presentation] 伊豆諸島火山岩のモリブデン同位体組成 (2022)
  • Author(s): 田村 達也、横山 哲也、石川 晃、栗谷 豪、Gautam Ikshu
  • Organizer: JpGU 2022, 幕張
• [Presentation] Rare-earth element imaging of fine-grained calcium and aluminum-rich inclusions in Allende meteorite. (2022)
  • Author(s): Masuda, Y., Niki, S., Yokoyama, T., Hirata, T.
  • Organizer: JpGU 2022, 幕張
• [Presentation] コロンビア, ゴルゴナ島に産する顕生代コマチアイトのマグマ源：オスミウム同位体不均質性からの考察 (2022)
  • Author(s): 井原 悠太、石川 晃、清水 健二、横山 哲也
  • Organizer: JpGU 2022, 幕張
• [Presentation] 炭素質隕石・非炭素質隕石の同位体組成バリエーション (2022)
  • Author(s): 深井稜汰, 荒川創太, 本間和明, 横山哲也, 奥住聡, 嶌生有理
  • Organizer: JpGU 2022, 幕張
• [Presentation] The compositional dichotomy of ca. 3.3 Ga komatiites from the West Pilbara (2022)
  • Author(s): Yusuke Kubota, Shun Nakano, Akira Ishikawa, Yuichiro Ueno
  • Organizer: Goldschmidt Conference, Hawaii, USA.
  • Invited
• [Presentation] Thermal structure of oceanic lithosphere constrained from the petit-spot mantle xenoliths (2022)
  • Author(s): Yuka Niwa, Akira Ishikawa, Norikatsu Akizawa
  • Organizer: Goldschmidt Conference, Hawaii, USA.
• [Presentation] Can the slightly depleted mantle be a high 3He/4He reservoir? (2022)
  • Author(s): Ryo Fujita, Akira Ishikawa, Hirochika Sumino, Michael O. Garcia
  • Organizer: Goldschmidt Conference, Hawaii, USA.
• [Presentation] Mantle sources of Phanerozoic komatiite from Gorgona Island, Colombia: Implication from osmium isotope heterogeneity (2022)
  • Author(s): Yuka Niwa, Akira Ishikawa, Norikatsu Akizawa
  • Organizer: JpGU 2022, 幕張
• [Presentation] Evidence for suboceanic small-scale convection from a “garnet”-bearing lherzolite xenolith, Aitutaki Island, Cook Islands (2022)
  • Author(s): Norikatsu Akizawa, Kazuhito Ozawa, Tetsu Kogiso, Akira Ishikawa, Simon Richard Wallis, Tatsuhiko Kawamoto, Akihiro Tamura, Tomoaki Morishita
  • Organizer: JpGU 2022, 幕張
• [Presentation] 海洋リソスフェアの温度構造：マントル捕獲岩研究からの視点 (2022)
  • Author(s): 石川 晃, 藤田 遼, 丹羽 佑果, 秋澤 紀克
  • Organizer: 日本地球化学会2022年会, 高知大学
• [Presentation] 前弧域の枯渇したマントルカンラン岩が記録する古溶融イベント (2022)
  • Author(s): 秋澤 紀克, 石川 晃, 石井 輝秋
  • Organizer: 日本地球化学会2022年会, 高知大学
• [Presentation] クック諸島産マントル捕獲岩から推定する太平洋プレートの熱化学構構造 (2022)
  • Author(s): 秋澤 紀克, 大嶋 ちひろ, 石川 晃, 角野 浩史, 小澤 一仁, 佐藤 侑人, 浜田 盛久
  • Organizer: 日本地球化学会2022年会, 高知大学