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2021 Fiscal Year Annual Research Report

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

Research Project

Project/Area Number 19H00715
Research InstitutionTokyo 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, 准教授 (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

昨年度に引き続き、太古代試料であるアカスタ片麻岩体苦鉄質岩のMo同位体分析を実施した。その結果、標準試料より低い94Mo/96Moおよび95Mo/96Mo比を持つ(=s-processに富む)試料が2点発見されたが、観察されたMo同位体異常の程度はごくわずかであった。この2点を除くほとんどの太古代試料は、誤差範囲で現代マントルと一致するMo同位体組成を持つことが分かった。
また、核合成起源Mo同位体異常に加え、太古代試料のMo安定同位体分別(MDF)測定も行うため、分析法の立ち上げを行った。ダブルスパイクTIMS法を用いて現代の玄武岩である伊豆大島や新島の試料を測定したところ、先行研究と一致する結果を得た。分析に必要なMo量は50-100 ngと微量であり、太古代試料に十分適用可能であることが分かった。
更に、コマチアイトの親鉄元素および親銅元素存在度を精密測定するため、分析法の立ち上げを行った。サンプルに濃縮同位体スパイクを加え、Carius tubeを用いて酸分解し、得られた溶液をトリプル四重極型ICP-MS(iCAP-TQ)で測定した。ガス反応セルを用いて干渉分子イオンを軽減させて測定することにより、高精度・高確度のデータを得ることに成功した。
一方、地球集積モデルに関しては、初期太陽系の炭素質コンドライト(CC)―非炭素質隕石(NC)同位体二分性と地球の原材料物質との関係を数値計算から求めた。その結果、地球の原材料の90%はNC的、10%はCC的物質で構成されることが判明した。更に、Late Accretionで加わった物質も約90%がNC的、10%がCC的であることが明らかになった。これは、CC的物質がLate Accretionで加わったとする従来の仮説を覆す結果であるが、太古代試料と現世マントルのMo同位体組成に大きな違いがない、という我々の分析結果とは矛盾しない。

Current Status of Research Progress
Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

太古代試料のMo同位体分析では、当初想定していた大きなs-processの異常がほとんど観察されず、原始地球と現世マントルが同じMo同位体組成を保持している可能性が示された。これは原始地球とLate Accretionで加わった物質が同じMo同位体組成を持っていたことを意味する。一方、分担者の数値計算からも原始地球とLate Accretion物質がほぼ同一のNC:CC比率(9:1)を持つことが示されており、太古代岩石試料の同位体分析の結果と数値計算による地球形成モデルとが矛盾していないという結果が得られた。このように、本課題の目標である「実験に基づく地球化学的研究」と「理論に基づく惑星科学的研究」との融合が実を結びつつある。新型コロナウイルス蔓延による実験上の制約があり、ここまで得られた太古代試料のMo同位体分析点数は必ずしも多くないが、本課題はおおむね順調に進展しているといえる。

Strategy for Future Research Activity

太古代試料のMo同位体分析に関しては、核合成起源同位体異常を検出した2試料の測定を繰り返し行い、異常の確からしさを調べる。並行して、昨年度開発したダブルスパイク法によるMo安定同位体分別の測定も実施する。また、初期地球に大きく寄与したと考えられるNC隕石に関して、先行研究で未測定あるいは測定数が著しく少ない試料(メソシデライト、ユークライト、未分類エイコンドライトなど)を対象にMo同位体分析を行う。
コマチアイトの分析に関しては、トリプル四重極ICP-MSを用いて親鉄元素および親銅元素存在度を精密測定し、初期地球から現世にいたるマントルの親鉄元素および親銅元素存在度の時間変化を調べる。
もし太古代試料がごくわずかな核合成起源Mo同位体異常を持つのであれば、それは原始地球とLate Accretion物質の間にわずかな組成の違い、すなわちNC:CCの比率の違いが存在することを意味する。太古代試料のMo同位体組成を決定し、それが数値計算で再現できるかどうかを調べる。

  • Research Products

    (51 results)

All 2022 2021

All Journal Article (20 results) (of which Int'l Joint Research: 9 results,  Peer Reviewed: 20 results,  Open Access: 8 results) Presentation (31 results) (of which Int'l Joint Research: 16 results,  Invited: 1 results)

  • [Journal Article] Chemical and Isotopic Evaluation of a Microsampling Method using Laser Ablation and Membrane Filter2022

    • Author(s)
      Masuda Yuki、Yokoyama Tetsuya、Okabayashi Satoki、Ishikawa Akira、Iwamori Hikaru
    • Journal Title

      Geostandards and Geoanalytical Research

      Volume: in press Pages: in press

    • DOI

      10.1111/ggr.12426

    • Peer Reviewed
  • [Journal Article] Geochemical composition of dykes along the Cameroon Line (CL): Petrogenesis and similarities with the Central Atlantic Magmatic Province2022

    • Author(s)
      Asaah Asobo Nkengmatia Elvis、Yokoyama Tetsuya、Iwamori Hikaru、Aka Festus Tongwa、Tamen Jules、Kuritani Takeshi、Usui Tomohiro、Hasegawa Takeshi、Fozing Eric Martial
    • Journal Title

      Geochemistry

      Volume: in press Pages: 125865~125865

    • DOI

      10.1016/j.chemer.2022.125865

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Geochemical constraints on the formation of chondrules: Implication from Os and Fe isotopes and HSE abundances in metals from CR chondrites2022

    • Author(s)
      Nakanishi Nao、Yokoyama Tetsuya、Okabayashi Satoki、Iwamori Hikaru、Hirata Takafumi
    • Journal Title

      Geochimica et Cosmochimica Acta

      Volume: 319 Pages: 254~270

    • DOI

      10.1016/j.gca.2021.11.009

    • Peer Reviewed
  • [Journal Article] Large planets may not form fractionally large moons2022

    • Author(s)
      Nakajima Miki、Genda Hidenori、Asphaug Erik、Ida Shigeru
    • Journal Title

      Nature Communications

      Volume: 13 Pages: -

    • DOI

      10.1038/s41467-022-28063-8

    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Martian moons exploration MMX: sample return mission to Phobos elucidating formation processes of habitable planets2022

    • Author(s)
      Kuramoto Kiyoshi、Kawakatsu Yasuhiro、Fujimoto Masaki、Araya Akito、Barucci Maria Antonietta、Genda Hidenori、et al.
    • Journal Title

      Earth, Planets and Space

      Volume: 74 Pages: -

    • DOI

      10.1186/s40623-021-01545-7

    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Survey of impact glasses in shergottites searching for Martian sulfate using X-ray absorption near-edge structure2021

    • Author(s)
      Shidare Masashi、Nakada Ryoichi、Usui Tomohiro、Tobita Minato、Shimizu Kenji、Takahashi Yoshio、Yokoyama Tetsuya
    • Journal Title

      Geochimica et Cosmochimica Acta

      Volume: 313 Pages: 85~98

    • DOI

      10.1016/j.gca.2021.08.026

    • Peer Reviewed
  • [Journal Article] High-μ signature in lavas of Mt. Oku: Implications for lithospheric and asthenospheric contributions to the magmatism of the Cameroon Volcanic Line (West Africa)2021

    • Author(s)
      Asaah A.N.E.、Yokoyama T.、Iwamori H.、Aka F.T.、Kuritani T.、Usui T.、Tamen J.、Gountie Dedzo M.、Chako-Tchamabe B.、Hasegawa T.、Nche L.A.、Ohba T.
    • Journal Title

      Lithos

      Volume: 400-401 Pages: 106416~106416

    • DOI

      10.1016/j.lithos.2021.106416

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Simultaneous Determination of Insoluble Fluoride‐Forming and High Field‐Strength Element Abundances in Rock Samples by ICP‐QMS through Isotope Dilution‐Internal Standardisation2021

    • Author(s)
      Kagami Saya、Yokoyama Tetsuya
    • Journal Title

      Geostandards and Geoanalytical Research

      Volume: 45 Pages: 679~699

    • DOI

      10.1111/ggr.12394

    • Peer Reviewed
  • [Journal Article] Variable refractory lithophile element compositions of planetary building blocks: Insights from components of enstatite chondrites2021

    • Author(s)
      Yoshizaki Takashi、Ash Richard D.、Lipella Marc D.、Yokoyama Tetsuya、McDonough William F.
    • Journal Title

      Geochimica et Cosmochimica Acta

      Volume: 308 Pages: 173~187

    • DOI

      10.1016/j.gca.2021.05.057

    • Peer Reviewed
  • [Journal Article] MIRS: an imaging spectrometer for the MMX mission2021

    • Author(s)
      Barucci Maria Antonietta、et al.
    • Journal Title

      Earth, Planets and Space

      Volume: 73 Pages: -

    • DOI

      10.1186/s40623-021-01423-2

    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] The Onset of a Globally Ice‐Covered State for a Land Planet2021

    • Author(s)
      Kodama T.、Genda H.、Leconte J.、Abe‐Ouchi A.
    • Journal Title

      Journal of Geophysical Research: Planets

      Volume: 126 Pages: -

    • DOI

      10.1029/2021JE006975

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Numerous chondritic impactors and oxidized magma ocean set Earth’s volatile depletion2021

    • Author(s)
      Sakuraba Haruka、Kurokawa Hiroyuki、Genda Hidenori、Ohta Kenji
    • Journal Title

      Scientific Reports

      Volume: 11 Pages: -

    • DOI

      10.1038/s41598-021-99240-w

    • Peer Reviewed / Open Access
  • [Journal Article] Tidal Evolution of the Eccentric Moon around Dwarf Planet (225088) Gonggong2021

    • Author(s)
      Arakawa Sota、Hyodo Ryuki、Shoji Daigo、Genda Hidenori
    • Journal Title

      The Astronomical Journal

      Volume: 162 Pages: 226~226

    • DOI

      10.3847/1538-3881/ac1f91

    • Peer Reviewed / Open Access
  • [Journal Article] SPH simulations for shape deformation of rubble-pile asteroids through spinup: The challenge for making top-shaped asteroids Ryugu and Bennu2021

    • Author(s)
      Sugiura Keisuke、Kobayashi Hiroshi、Watanabe Sei-ichiro、Genda Hidenori、Hyodo Ryuki、Inutsuka Shu-ichiro
    • Journal Title

      Icarus

      Volume: 365 Pages: 114505~114505

    • DOI

      10.1016/j.icarus.2021.114505

    • Peer Reviewed / Open Access
  • [Journal Article] Erosion and Accretion by Cratering Impacts on Rocky and Icy Bodies2021

    • Author(s)
      Hyodo Ryuki、Genda Hidenori
    • Journal Title

      The Astrophysical Journal

      Volume: 913 Pages: 77~77

    • DOI

      10.3847/1538-4357/abf6d8

    • Peer Reviewed / Open Access
  • [Journal Article] Highly refractory dunite formation at Gibbs Island and Bruce Bank, and its role in the evolution of the circum-Antarctic continent2021

    • Author(s)
      Akizawa Norikatsu、Yamaguchi Asuka、Tani Kenichiro、Ishikawa Akira、Fujita Ryo、Choi Sung Hi
    • Journal Title

      The Canadian Mineralogist

      Volume: 59 Pages: 1731~1753

    • DOI

      10.3749/canmin.2100030

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Sedimentary record of Upper Triassic impact in the Lagonegro Basin, southern Italy: Insights from highly siderophile elements and Re-Os isotope stratigraphy across the Norian/Rhaetian boundary2021

    • Author(s)
      Sato Honami、Ishikawa Akira、Onoue Tetsuji、Tomimatsu Yuki、Rigo Manuel
    • Journal Title

      Chemical Geology

      Volume: 586 Pages: 120506~120506

    • DOI

      10.1016/j.chemgeo.2021.120506

    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Halogen heterogeneity in the subcontinental lithospheric mantle revealed by I/Br ratios in kimberlites and their mantle xenoliths from South Africa, Greenland, China, Siberia, Canada, and Brazil2021

    • Author(s)
      Toyama Chiaki、Sumino Hirochika、Okabe Nobuaki、Ishikawa Akira、Yamamoto Junji、Kaneoka Ichiro、Muramatsu Yasuyuki
    • Journal Title

      American Mineralogist

      Volume: 106 Pages: 1890~1899

    • DOI

      10.2138/am-2021-7332

    • Peer Reviewed
  • [Journal Article] Seismic evidence for a thermochemical mantle plume underplating the lithosphere of the Ontong Java Plateau2021

    • Author(s)
      Isse Takehi、Suetsugu Daisuke、Ishikawa Akira、Shiobara Hajime、Sugioka Hiroko、Ito Aki、Kawano Yuki、Yoshizawa Kazunori、Ishihara Yasushi、Tanaka Satoru、Obayashi Masayuki、Tonegawa Takashi、Yoshimitsu Junko
    • Journal Title

      Communications Earth & Environment

      Volume: 2 Pages: -

    • DOI

      10.1038/s43247-021-00169-9

    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Testing the Ontong Java Nui Hypothesis: The Largest Supervolcano Ever on Earth2021

    • Author(s)
      SANO Takashi、TEJADA Maria Luisa G.、NAKANISHI Masao、HANYU Takeshi、MIURA Seiichi、SUETSUGU Daisuke、TONEGAWA Takashi、ISHIKAWA Akira、SHIMIZU Kenji、SHIMIZU Shoka
    • Journal Title

      Journal of Geography (Chigaku Zasshi)

      Volume: 130 Pages: 559~584

    • DOI

      10.5026/jgeography.130.559

    • Peer Reviewed
  • [Presentation] Multi-isotopic analyses of bulk Ryugu samples returned by the Hayabusa2 mission2022

    • Author(s)
      Yokoyama, T., et al.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] Chemical and isotopic characterization of asteroid Ryugu.2022

    • Author(s)
      Yurimoto, H., Yokoyama, T., et al.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] The oxygen isotopic composition of samples returned from asteroid Ryugu: Evidence for similarity to CI chondrites.2022

    • Author(s)
      Young, E.D., Tang, H., Tafla, L., Pack, A., Rocco, T.Di, Yurimoto, H., Yokoyama, T., et al.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] In-situ oxygen and manganese-chromium isotope studies of Ryugu: Implications to temperature and timing of aqueous activity.2022

    • Author(s)
      Nagashima, K., Yokoyama, T., et al.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] Sampling mass and chemical heterogeneities among Ryugu samples returned by the Hayabusa2 mission.2022

    • Author(s)
      Dauphas, N., Yokoyama, T., et al.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] Speciation of sulfur in carbonates in a 4.1-billion-year-old Martian meteorite.2022

    • Author(s)
      Kajitani, I, Nakada, R., Koike, M., Tanabe, G., Usui, T., Marsuura, R., Fukushi, K., Kurokawa, H., Yokoyama, T.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] Origin of nucleosynthetic Sr isotope anomalies in fine grained calcium and aluminum-rich inclusions from Allende.2022

    • Author(s)
      Masuda, Y., Yokoyama, T.
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] Formation of Ryugu: Approach from numerical simulations with physical properties measured in Ryugu samples2022

    • Author(s)
      Genda, H., K. Kurosawa, S. Wakita, R. Hyodo, K. Sugiura, S. Tanaka, T. Nakamura, H. Yurimoto, T. Noguchi, R. Okazaki, H. Yabuta, H. Naraoka, K. Sakamoto, S. Tachibana, S. Watanabe, and Y. Tsuda
    • Organizer
      Lunar and Planetary Science Conference, The Woodlands, USA (hybrid)
    • Int'l Joint Research
  • [Presentation] Formation of Earth and Its Early Evolution2022

    • Author(s)
      Genda, H.
    • Organizer
      The 10th ELSI International Symposium
    • Int'l Joint Research
  • [Presentation] Progress of chemical characterization of asteroid Ryugu samples.2021

    • Author(s)
      Yurimoto, H., Yokoyama, T., et al.
    • Organizer
      Hayabusa Symposium 2021, Virtual
    • Int'l Joint Research
  • [Presentation] Development of multi-isotopic analyses of asteroid samples returned by the Hayabusa2 mission.2021

    • Author(s)
      Yokoyama, T., Gautam, I., Ohkuma, Y., Iizuka, T., Horan, M.F., Carlson, R.W.
    • Organizer
      Goldschmidt Conference, Virtual
    • Int'l Joint Research
  • [Presentation] Development of a technique for multi-isotopic analyses of asteroid samples returned by the Hayabusa2 mission.2021

    • Author(s)
      Yokoyama, T., Gautam, I., Ohkuma, Y., Iizuka, T.
    • Organizer
      JpGU 2021, Virtual.
  • [Presentation] 小惑星サンプルリターン試料のマルチ同位体分析2021

    • Author(s)
      横山哲也、 Ikshu Gautam、大熊悠介、飯塚毅
    • Organizer
      質量分析討論会2021
  • [Presentation] 伊豆諸島火山岩のモリブデン同位体組成2021

    • Author(s)
      田村達也、横山哲也、栗谷豪
    • Organizer
      日本地球化学会2021年会
  • [Presentation] Allende隕石中細粒CAIに見られる核合成起源のSr同位体異常の多様性2021

    • Author(s)
      増田雄樹、横山哲也
    • Organizer
      日本地球化学会2021年会
  • [Presentation] 高精度Nd同位体比測定による平衡論的同位体効果の同定2021

    • Author(s)
      深井稜汰, 若木重行, 横山哲也
    • Organizer
      日本地球化学会2021年会
  • [Presentation] Erosion and accretion by cratering impacts on rocky and icy bodies: Formulation of scaling relations for high-speed ejecta2021

    • Author(s)
      Genda, H., and Hyodo, R.
    • Organizer
      Europlanet Science Congress 2021
    • Int'l Joint Research
  • [Presentation] 後期集積の現状理解2021

    • Author(s)
      玄田英典
    • Organizer
      第23回 惑星圏研究会
    • Invited
  • [Presentation] Missing negative Δ33S reservoir in mantle inferred from 2.7 Ga komatiite2021

    • Author(s)
      Yusuke Kubota,Fumihiro Matsu'ura,Kenji Shimizu,石川 晃,上野 雄一郎
    • Organizer
      Goldschmdit Virtual 2021
    • Int'l Joint Research
  • [Presentation] Sampling source heterogeneities that bind the Ontong Java Nui puzzle together2021

    • Author(s)
      Maria Luisa Garcia Tejada,Takashi Sano,Takeshi Hanyu,Anthony Koppers,Masao Nakanishi,Akira Ishikawa,Takashi Miyazaki,Kenichiro Tani,Shoka Shimizu,Qing Chang,Bogdan Vaglarov
    • Organizer
      Goldschmdit Virtual 2021
    • Int'l Joint Research
  • [Presentation] Highly siderophile elements behavior in the Paleoarchean Camel Creek komatiites from East Pilbara Terrane, Western Australia2021

    • Author(s)
      Shun Nakano,Akira Ishikawa,Yuichiro Ueno,Tetsuya Yokoyama
    • Organizer
      Goldschmidt Virutal 2021
    • Int'l Joint Research
  • [Presentation] Highly siderophile element mobility during serpentinization of mantle wedge peridotite2021

    • Author(s)
      Akira Ishikawa,Natsuki Nakamura,Tetsuya Yokoyama
    • Organizer
      Goldschmdt Virtual 2021
    • Int'l Joint Research
  • [Presentation] 海洋リソスフェアと地球表層環境 ?海洋プレート生成史が地球表層環境に与えた影響?2021

    • Author(s)
      黒田 潤一郎,後藤 孝介,石川 晃,黒柳 あずみ
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] パイロライトモデルを応用した始源的マントルの強親鉄元素存在度の推定2021

    • Author(s)
      小木曽 哲,石川 晃,秋澤 紀克
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] Highly refractory dunite formation in Gibbs Island and Bruce Bank, and its role in the evolution of the circum-Antarctic continent2021

    • Author(s)
      秋澤 紀克,山口 飛鳥,大嶋 ちひろ,谷 健一郎,石川 晃,藤田 遼,CHOI SUNG HI
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] 高-Mg安山岩及び玄武岩中の強親鉄性元素の特徴とカムチャッカ前弧域における第四紀島弧火成活動の成因2021

    • Author(s)
      西澤 達治,三ツ出 唯利,中村 仁美,Churikova Tatiana,Gordeychik Boris,石川 晃,岩森 光
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] Hydrogen isotope of the mantle source in Pitcairn Island2021

    • Author(s)
      小澤 恭弘,石川 晃,羽生 毅,清水 健二,牛久保 孝行,浜田 盛久,岩森 光
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] Volcanism along the eastern margin of the Ontong Java Plateau: More reasons to test the Ontong Java Nui hypothesis by scientific ocean drilling2021

    • Author(s)
      Maria Luisa Tejada,Takashi Sano,Takeshi Hanyu,Anthony A. P. Koppers,Masao Nakanishi,Akira Ishikawa,Takashi Miyazaki,Kenichiro Tani,Shoka Shimizu,Qing Chang,Bogdan Stefanov Vaglarov
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] Highly siderophile elements in Earth's oldest rocks from Acasta Gniess Complex, Canada: an impact melt origin or not?2021

    • Author(s)
      石川 晃,越田 渓子,鈴木 勝彦,横山 哲也,小宮 剛
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] Role of fluid rock reaction for the production of FOZO isotopic composition2021

    • Author(s)
      下田 玄,小木曽 哲,鈴木 勝彦,石川 晃,秋澤 紀克
    • Organizer
      日本地球惑星科学連合2021年大会
  • [Presentation] 強親鉄性元素及びRe-Os同位体系から探るSredinny Range北部(カムチャッカ)のマグマ生成プロセス2021

    • Author(s)
      三ツ出 唯利,西澤 達治,中村 仁美,Churikova Tatiana,Gordeychik Boris,石川 晃,岩森 光
    • Organizer
      日本地球惑星科学連合2021年大会

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Published: 2022-12-28  

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