Updated on 2025/10/07

写真a

 
Ishikawa Akira
 
Organization
School of Science Associate Professor
Title
Associate Professor
External link

News & Topics

Degree

  • Master of Sceince ( Tokyo Institute of Technology )

  • Doctor of Science ( Tokyo Institute of Technology )

Research Interests

  • 岩石・鉱物・鉱床学

  • 地球化学

  • 地殻・マントル物質

  • 白金族元素

Research Areas

  • Natural Science / Space and planetary sciences

  • Natural Science / Solid earth sciences

Research History

  • Tokyo Institute of Technology   Department of Earth and Planetary Sciences   Associate Professor

    2018.4

    　 More details

Professional Memberships

Papers

  • The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites Reviewed

    Fridolin Spitzer, Thorsten Kleine, Christoph Burkhardt, Timo Hopp, Tetsuya Yokoyama, Yoshinari Abe, Jérôme Aléon, Conel M. O’D Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Kouki Kitajima, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Mayu Morita, Fréderic Moynier, Kazuko Motomura, Izumi Nakai, Kazuhide Nagashima, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Science Advances   10 ( 39 )   2024.9

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：American Association for the Advancement of Science (AAAS)  

    The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grains among the carbonaceous chondrite parent bodies. The CI chondrites incorporated these grains more efficiently, possibly because they formed at the end of the disk’s lifetime, when planetesimal formation was also triggered by photoevaporation of the disk. Isotopic variations among carbonaceous chondrites may thus reflect fractionation of distinct dust components from a common reservoir, implying CI chondrites/Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites.

    DOI： 10.1126/sciadv.adp2426

    researchmap

  • Microstructures, hydrogen concentrations, and seismic properties of a tectonically exhumed sliver of oceanic mantle lithosphere, Moa Island, Timor-Tanimbar outer-arc, eastern Indonesia

    Demouchy, S., Barou, F., Ishikawa, A., Gard{\'e}s, E., Tommasi, A.

    Tectonophysics   887   2024.9

    　More details

    Language：English   Publishing type：Research paper (scientific journal)  

    DOI： 10.1016/j.tecto.2024.230443

    Scopus

    researchmap

  • Pyrrhotites in asteroid 162173 Ryugu: Records of the initial changes on their surfaces with aqueous alteration

    Hiroharu Yui, Shu-hei Urashima, Morihiko Onose, Mayu Morita, Shintaro Komatani, Izumi Nakai, Yoshinari Abe, Yasuko Terada, Hisashi Homma, Kazuko Motomura, Kiyohiro Ichida, Tetsuya Yokoyama, Kazuhide Nagashima, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Peter Hoppe, Gary R. Huss, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Kouki Kitajima, Thorsten Kleine, Sasha Krot, Ming-Chang Liu, Yuki Masuda, Frédéric Moynier, Ann Nguyen, Larry Nittler, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Tommaso Di Rocco, Sara S. Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Shigekazu Yoneda, Edward D. Young, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Geochimica et Cosmochimica Acta   379   172 - 183   2024.8

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

    DOI： 10.1016/j.gca.2024.06.016

    researchmap

  • Evidence for suboceanic small-scale convection from a “garnet”-bearing lherzolite xenolith from Aitutaki Island, Cook Islands

    Norikatsu Akizawa, Kazuhito Ozawa, Tetsu Kogiso, Akira Ishikawa, Akira Miyake, Yohei Igami, Simon R. Wallis, Takayoshi Nagaya, Chihiro Ohshima, Ryo Fujita, Tatsuhiko Kawamoto, Akihiro Tamura, Tomoaki Morishita, Shoji Arai, Atsushi Yasumoto

    Progress in Earth and Planetary Science   11 ( 1 )   2024.7

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

    Abstract

    Garnet peridotite xenoliths have been rarely reported from suboceanic mantle. Petrographic and geochemical characteristics of garnet-bearing oceanic peridotite xenoliths provide precious information on dynamics of the suboceanic lithosphere and asthenosphere interaction. We examined a lherzolite xenolith included in olivine nephelinite lava from Aitutaki Island, a member of the Cook-Austral volcanic chain. The lherzolite xenolith contains reddish fine-grained (< 5 µm in size) mineral aggregates (FMAs) with size range of 0.5–6 mm, consisting of olivine, calcic and sodic plagioclases, aluminous spinel, native iron, and nepheline. Microstructural observations and chemical data corroborate that the FMA is a decomposed pyrope-rich garnet including chromian spinel grains with an irregular highly indented morphology in the center. The FMA is surrounded by pyroxene-poor and olivine-rich aureole. The spatial and morphological relationships of FMA and chromian spinel with pyroxene-depleted margin suggest a reaction of aluminous spinel + pyroxenes → pyrope-rich garnet + olivine, which requires a compression before decomposition of the garnet to FMA. An orthopyroxene grain shows slight but clear chemical zoning characterized by increase in Al, Ca, and Cr from the grain center to the rim. The zoning patterns of Al and Ca in the orthopyroxene grain can be modeled by diffusion-controlled solid-state reactions induced by pressure and temperature changes, keeping surface concentrations in equilibrium with the other coexisting mineral phases. The results indicate that the mantle, from which the lherzolite xenolith was derived, underwent isothermal decompression followed by a weak heating on a time scale of a few tenths of million years before the xenolith extraction. From the deduced compression and decompression histories, we hypothesize that the mantle beneath Aitutaki Island was once dragged down to a garnet-stable deep mantle region and brought up later by small-scale sublithospheric convection.

    DOI： 10.1186/s40645-024-00643-w

    researchmap

    Other Link： https://link.springer.com/article/10.1186/s40645-024-00643-w/fulltext.html

  • Stable carbon and oxygen isotope signatures of mantle-derived calcite in Aitutaki lherzolite xenolith: Implications for organic carbon cycle in the oceanic mantle

    Norikatsu Akizawa, Toyoho Ishimura, Masako Yoshikawa, Tetsu Kogiso, Akira Ishikawa, Kazuhide Mimura

    Marine Geology   107363 - 107363   2024.7

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

    DOI： 10.1016/j.margeo.2024.107363

    researchmap

  • Disequilibrium oxygen isotope distribution among aqueously altered minerals in Ryugu asteroid returned samples

    Noriko T. Kita, Kouki Kitajima, Kazuhide Nagashima, Noriyuki Kawasaki, Naoya Sakamoto, Wataru Fujiya, Yoshinari Abe, Jérôme Aléon, Conel M. O'D. Alexander, Sachiko Amari, Yuri Amelin, Ken‐ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon‐Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming‐Chang Liu, Yuki Masuda, Kevin D. McKeegan, Mayu Morita, Kazuko Motomura, Frédéric Moynier, Izumi Nakai, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing‐Zhu Yin, Tetsuya Yokoyama, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai‐Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei‐ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Meteoritics & Planetary Science   2024.4

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Wiley  

    Abstract

    Oxygen 3‐isotope ratios of magnetite and carbonates in aqueously altered carbonaceous chondrites provide important clues to understanding the evolution of the fluid in the asteroidal parent bodies. We conducted oxygen 3‐isotope analyses of magnetite, dolomite, and breunnerite in two sections of asteroid Ryugu returned samples, A0058 and C0002, using a secondary ion mass spectrometer (SIMS). Magnetite was analyzed by using a lower primary ion energy that reduced instrumental biases due to the crystal orientation effect. We found two groups of magnetite data identified from the SIMS pit morphologies: (1) higher δ18O (from 3‰ to 7‰) and ∆17O (~2‰) with porous SIMS pits mostly from spherulitic magnetite, and (2) lower δ18O (~ −3‰) and variable ∆17O (0‰–2‰) mostly from euhedral magnetite. Dolomite and breunnerite analyses were conducted using multi‐collection Faraday cup detectors with precisions ≤0.3‰. The instrumental bias correction was applied based on carbonate compositions in two ways, using Fe and (Fe + Mn) contents, respectively, because Ryugu dolomite contains higher amounts of Mn than the terrestrial standard. Results of dolomite and breunnerite analyses show a narrow range of ∆17O; 0.0‰–0.3‰ for dolomite in A0058 and 0.2‰–0.8‰ for dolomite and breunnerite in C0002. The majority of breunnerite, including large ≥100 μm grains, show systematically lower δ18O (~21‰) than dolomite (25‰–30‰ and 23‰–27‰ depending on the instrumental bias corrections). The equilibrium temperatures between magnetite and dolomite from the coarse‐grained lithology in A0058 are calculated to be 51 ± 11°C and 78 ± 14°C, depending on the instrumental bias correction scheme for dolomite; a reliable temperature estimate would require a Mn‐bearing dolomite standard to evaluate the instrumental bias corrections, which is not currently available. These results indicate that the oxygen isotope ratios of aqueous fluids in the Ryugu parent asteroid were isotopically heterogeneous, either spatially, or temporary. Initial water ice accreted to the Ryugu parent body might have ∆17O > 2‰ that was melted and interacted with anhydrous solids with the initial ∆17O < 0‰. In the early stage of aqueous alteration, spherulitic magnetite and calcite formed from aqueous fluid with ∆17O ~ 2‰ that was produced by isotope exchange between water (∆17O > 2‰) and anhydrous solids (∆17O < 0‰). Dolomite and breunnerite, along with some magnetite, formed at the later stage of aqueous alteration under higher water‐to‐rock ratios where the oxygen isotope ratios were nearly at equilibrium between fluid and solid phases. Including literature data, δ18O of carbonates decreased in the order calcite, dolomite, and breunnerite, suggesting that the temperature of alteration might have increased with the degree of aqueous alteration.

    DOI： 10.1111/maps.14163

    researchmap

  • Brief and intensive volcanic emissions from Ontong Java Nui heralded Oceanic Anoxic Event 1a Reviewed

    Matsumoto, H., Goto, K.T., Shimoda, G., Watanabe, Y., Shirai, K., Tejada, M.L.G., Ishikawa, A., Ando, A., Sano, T., Kuroda, J., Suzuki, K.

    Communications Earth and Environment   5 ( 1 )   155   2024.3

    　More details

    Language：English   Publishing type：Research paper (scientific journal)  

    DOI： 10.1038/s43247-024-01310-0

    Scopus

    researchmap

  • Pervasive aqueous alteration in the early Solar System revealed by potassium isotopic variations in Ryugu samples and carbonaceous chondrites

    Yan Hu, Frédéric Moynier, Wei Dai, Marine Paquet, Tetsuya Yokoyama, Yoshinari Abe, Jérôme Aléon, Conel M. O'D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Koki Kitajima, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Mayu Morita, Kazuko Motomura, Izumi Nakai, Kazuhide Nagashima, David Nesvorný, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Icarus   409   115884 - 115884   2024.2

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

    DOI： 10.1016/j.icarus.2023.115884

    researchmap

  • Applicability of quartz tube digestion for the determination of highly siderophile and volatile chalcophile element abundances with Os isotopic compositions using ICP-MS/MS and N-TIMS

    Fujita, R., Nakano, S., Yokoyama, T., Ishikawa, A.

    Geochemical Journal   58 ( 1 )   2024

    　More details

    Publishing type：Research paper (scientific journal)  

    DOI： 10.2343/geochemj.GJ24002

    Scopus

    researchmap

  • Molybdenum isotopic compositions in volcanic rocks from Northern Izu arc (Izu-Oshima, Niijima, and Kozushima) Reviewed

    Tatsuya Tamura, Tetsuya Yokoyama, Takeshi Kuritani, Akira Ishikawa

    Geochemical Journal   58 ( 2 )   51 - 70   2024

    　More details

    Publishing type：Research paper (scientific journal)  

    DOI： 10.11263/geochemj.GJ24005

    Scopus

    researchmap

  • Hydrogen in magnetite from asteroid Ryugu

    Al{\'e}on, J., Mostefaoui, S., Bureau, H., Vangu, D., Khodja, H., Nagashima, K., Kawasaki, N., Abe, Y., Alexander, C.M.O.D., Amari, S., Amelin, Y., Bajo, K., Bizzarro, M., Bouvier, A., Carlson, R.W., Chaussidon, M., Choi, B.-G., Dauphas, N., Davis, A.M., Di Rocco, T., Fujiya, W., Fukai, R., Gautam, I., Haba, M.K., Hibiya, Y., Hidaka, H., Homma, H., Hoppe, P., Huss, G.R., Ichida, K., Iizuka, T., Ireland, T.R., Ishikawa, A., Itoh, S., Kita, N.T., Kitajima, K., Kleine, T., Komatani, S., Krot, A.N., Liu, M.-C., Masuda, Y., Morita, M., Motomura, K., Moynier, F., Nakai, I., Nguyen, A., Nittler, L.R., Onose, M., Pack, A., Park, C., Piani, L., Qin, L., Russell, S.S., Sakamoto, N., Sch{\"o}nb, a}chler, M., Tafla, L., Tang, H., Terada, K., Terada, Y., Usui, T., Wada, S., Wadhwa, M., Walker, R.J., Yamashita, K., Yin, Q.-Z., Yokoyama, T., Yoneda, S., Young, E.D., Yui, H., Zhang, A.-C., Nakamura, T., Naraoka, H., Noguchi, T., Okazaki, R., Sakamoto, K., Yabuta, H., Abe, M., Miyazaki, A., Nakato, A., Nishimura, M., Okada, T., Yada, T., Yogata, K., Nakazawa, S., Saiki, T., Tanaka, S., Terui, F., Tsuda, Y., Watanabe, S., Yoshikawa, M., Tachibana, S., Yurimoto, H.

    Meteoritics and Planetary Science   59 ( 8 )   2024

    　More details

    Publishing type：Research paper (scientific journal)  

    DOI： 10.1111/maps.14139

    Scopus

    researchmap

  • Analysis of Cation Composition in Dolomites on the Intact Particles Sampled from Asteroid Ryugu Reviewed International coauthorship International journal

    Mayu Morita, Hiroharu Yui, Shu-hei Urashima, Morihiko Onose, Shintaro Komatani, Izumi Nakai, Yoshinari Abe, Yasuko Terada, Hisashi Homma, Kazuko Motomura, Kiyohiro Ichida, Tetsuya Yokoyama, Kazuhide Nagashima, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Peter Hoppe, Gary R. Huss, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Kouki Kitajima, Thorsten Kleine, Sasha Krot, Ming-Chang Liu, Yuki Masuda, Frédéric Moynier, Ann Nguyen, Larry Nittler, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Tommaso Di Rocco, Sara S. Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Shigekazu Yoneda, Edward D. Young, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Analytical Chemistry   2023.12

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

    DOI： 10.1021/acs.analchem.3c03463

    researchmap

  • Fine-grained interplanetary dust input during the Turonian (Late Cretaceous): evidence from osmium isotope and platinum group elements

    Hironao Matsumoto, Akira Ishikawa, Rodolfo Coccioni, Fabrizio Frontalini, Katsuhiko Suzuki

    SCIENTIFIC REPORTS   13 ( 1 )   2023.12

    　More details

    Language：English   Publishing type：Research paper (scientific journal)  

    DOI： 10.1038/s41598-023-49252-5

    Web of Science

    researchmap

  • Neodymium‐142 deficits and samarium neutron stratigraphy of C‐type asteroid (162173) Ryugu

    Zachary A. Torrano, Michelle K. Jordan, Timothy D. Mock, Richard W. Carlson, Ikshu Gautam, Makiko K. Haba, Tetsuya Yokoyama, Yoshinari Abe, Jérôme Aléon, Conel Alexander, Sachiko Amari, Yuri Amelin, Ken‐ichi Bajo, Martin Bizzarro, Audrey Bouvier, Marc Chaussidon, Byeon‐Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Ryota Fukai, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Koki Kitajima, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming‐Chang Liu, Yuki Masuda, Kevin D. McKeegan, Mayu Morita, Kazuko Motomura, Frédéric Moynier, Izumi Nakai, Kazuhide Nagashima, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing‐Zhu Yin, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai‐Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei‐ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Meteoritics & Planetary Science   2023.12

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Wiley  

    Abstract

    We report Nd and Sm isotopic compositions of four samples of Ryugu returned by the Hayabusa2 mission, including “A” (first touchdown) and “C” (second touchdown) samples, and several carbonaceous chondrites to evaluate potential genetic relationships between Ryugu and known chondrite groups and track the cosmic ray exposure history of Ryugu. We resolved Nd and Sm isotopic anomalies in small (<20 ng Nd and Sm) sample sizes via thermal ionization mass spectrometer using 1013 Ω amplifiers. Ryugu samples exhibit resolvable negative μ142Nd values consistent with carbonaceous chondrite values, suggesting that Ryugu is related to the parent bodies of carbonaceous chondrites. Ryugu's negative μ149Sm values are the result of exposure to galactic cosmic rays, as demonstrated by the correlation between 150Sm/152Sm and 149Sm/152Sm ratios that fall along the expected neutron capture correlation line. The neutron fluence calculated in the “A” samples (2.75 ± 1.94 × 1015 n cm−2) is slightly higher compared to the “C” samples (0.95 ± 2.04 × 1015 n cm−2), though overlapping within measurement uncertainty. The Sm results for Ryugu, at this level of precision, thus are consistent with a well‐mixed surface layer at least to the depths from which the “A” and “C” samples derive.

    DOI： 10.1111/maps.14109

    researchmap

  • The Magnesium Isotope Composition of Samples Returned from Asteroid Ryugu

    Martin Bizzarro, Martin Schiller, Tetsuya Yokoyama, Yoshinari Abe, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Kouki Kitajima, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Mayu Morita, Fréderic Moynier, Kazuko Motomura, Izumi Nakai, Kazuhide Nagashima, David Nesvorný, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    The Astrophysical Journal Letters   958 ( 2 )   L25 - L25   2023.11

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：American Astronomical Society  

    Abstract

    The nucleosynthetic isotope composition of planetary materials provides a record of the heterogeneous distribution of stardust within the early solar system. In 2020 December, the Japan Aerospace Exploration Agency Hayabusa2 spacecraft returned to Earth the first samples of a primitive asteroid, namely, the Cb-type asteroid Ryugu. This provides a unique opportunity to explore the kinship between primitive asteroids and carbonaceous chondrites. We report high-precision μ26Mg* and μ25Mg values of Ryugu samples together with those of CI, CM, CV, and ungrouped carbonaceous chondrites. The stable Mg isotope composition of Ryugu aliquots defines μ25Mg values ranging from –160 ± 20 ppm to –272 ± 30 ppm, which extends to lighter compositions relative to Ivuna-type (CI) and other carbonaceous chondrite groups. We interpret the μ25Mg variability as reflecting heterogeneous sampling of a carbonate phase hosting isotopically light Mg (μ25Mg ∼ –1400 ppm) formed by low temperature equilibrium processes. After correcting for this effect, Ryugu samples return homogeneous μ26Mg* values corresponding to a weighted mean of 7.1 ± 0.8 ppm. Thus, Ryugu defines a μ26Mg* excess relative to the CI and CR chondrite reservoirs corresponding to 3.8 ± 1.1 and 11.9 ± 0.8 ppm, respectively. These variations cannot be accounted for by in situ decay of 26Al given their respective 27Al/24Mg ratios. Instead, it requires that Ryugu and the CI and CR parent bodies formed from material with a different initial 26Al/27Al ratio or that they are sourced from material with distinct Mg isotope compositions. Thus, our new Mg isotope data challenge the notion that Ryugu and CI chondrites share a common nucleosynthetic heritage.

    DOI： 10.3847/2041-8213/ad09d9

    researchmap

    Other Link： https://iopscience.iop.org/article/10.3847/2041-8213/ad09d9/pdf

  • Water circulation in Ryugu asteroid affected the distribution of nucleosynthetic isotope anomalies in returned sample

    Tetsuya Yokoyama, Meenakshi Wadhwa, Tsuyoshi Iizuka, Vinai Rai, Ikshu Gautam, Yuki Hibiya, Yuki Masuda, Makiko K. Haba, Ryota Fukai, Rebekah Hines, Nicole Phelan, Yoshinari Abe, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Trevor Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Koki Kitajima, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Kevin D. McKeegan, Mayu Morita, Kazuko Motomura, Frédéric Moynier, Izumi Nakai, Kazuhide Nagashima, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara Russell, Naoya Sakamoto, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Science Advances   9 ( 45 )   2023.11

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：American Association for the Advancement of Science (AAAS)  

    Studies of material returned from Cb asteroid Ryugu have revealed considerable mineralogical and chemical heterogeneity, stemming primarily from brecciation and aqueous alteration. Isotopic anomalies could have also been affected by delivery of exogenous clasts and aqueous mobilization of soluble elements. Here, we show that isotopic anomalies for mildly soluble Cr are highly variable in Ryugu and CI chondrites, whereas those of Ti are relatively uniform. This variation in Cr isotope ratios is most likely due to physicochemical fractionation between 54 Cr-rich presolar nanoparticles and Cr-bearing secondary minerals at the millimeter-scale in the bulk samples, likely due to extensive aqueous alteration in their parent bodies that occurred after Solar System birth. In contrast, Ti isotopes were marginally affected by this process. Our results show that isotopic heterogeneities in asteroids are not all nebular or accretionary in nature but can also reflect element redistribution by water.

    DOI： 10.1126/sciadv.adi7048

    researchmap

  • Rhenium–osmium isotope evidence for the onset of volcanism in the central Panthalassa Ocean during the Norian “chaotic carbon episode”

    Honami Sato, Tatsuo Nozaki, Tetsuji Onoue, Akira Ishikawa, Katsuhito Soda, Kazutaka Yasukawa, Jun-Ichi Kimura, Qing Chang, Yasuhiro Kato, Manuel Rigo

    Global and Planetary Change   229   104239 - 104239   2023.9

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

    DOI： 10.1016/j.gloplacha.2023.104239

    researchmap

  • The Oxygen Isotopic Composition of Samples Returned from Asteroid Ryugu with Implications for the Nature of the Parent Planetesimal

    Haolan Tang, Edward D. Young, Lauren Tafla, Andreas Pack, Tommaso Di Rocco, Yoshinari Abe, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Motoo Ito, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Kouki Kitajima, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Kevin D. McKeegan, Mayu Morita, Kazuko Motomura, Frédéric Moynier, Kazuhide Nagashima, Izumi Nakai, Ann Nguyen, Larry Nittler, Morihiko Onose, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Naoya Sakamoto, Maria Schönbächler, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Tetsuya Yokoyama, Shigekazu Yoneda, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    The Planetary Science Journal   4 ( 8 )   144 - 144   2023.8

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：American Astronomical Society  

    Abstract

    We present oxygen isotopic analyses of fragments of the near-Earth Cb-type asteroid Ryugu returned by the Hayabusa2 spacecraft that reinforce the close correspondence between Ryugu and CI chondrites. Small differences between Ryugu samples and CI chondrites in ${ { \rm{\Delta } } }^{ { \prime} 17}{\rm{O } }$ can be explained at least in part by contamination of the latter by terrestrial water. The discovery that a randomly sampled C-complex asteroid is composed of CI-chondrite-like rock, combined with thermal models for formation prior to significant decay of the short-lived radioisotope 26Al, suggests that if lithified at the time of alteration, the parent body was small (≪50 km radius). If the parent planetesimal was large (>50 km in radius), it was likely composed of high-permeability, poorly lithified sediment rather than consolidated rock.

    DOI： 10.3847/psj/acea62

    researchmap

    Other Link： https://iopscience.iop.org/article/10.3847/PSJ/acea62/pdf

  • Carbonate record of temporal change in oxygen fugacity and gaseous species in asteroid Ryugu

    Wataru Fujiya, Noriyuki Kawasaki, Kazuhide Nagashima, Naoya Sakamoto, Conel M. O’D. Alexander, Noriko T. Kita, Kouki Kitajima, Yoshinari Abe, Jérôme Aléon, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Kevin D. McKeegan, Mayu Morita, Kazuko Motomura, Frédéric Moynier, Izumi Nakai, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Tetsuya Yokoyama, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    Nature Geoscience   16 ( 8 )   675 - +   2023.7

    　More details

    Language：English   Publishing type：Research paper (scientific journal)  

    DOI： 10.1038/s41561-023-01226-y

    Web of Science

    researchmap

    Other Link： https://www.nature.com/articles/s41561-023-01226-y

  • Abundant presolar grains and primordial organics preserved in carbon-rich exogenous clasts in asteroid Ryugu

    Ann. N. Nguyen, Prajkta Mane, Lindsay P. Keller, Laurette Piani, Yoshinari Abe, Jerome Aleon, Conel M. O'D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriyuki Kawasaki, Noriko T. Kita, Kouki Kitajima, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Kevin D. McKeegan, Mayu Morita, Kazuko Motomura, Frederic Moynier, Izumi Nakai, Kazuhide Nagashima, David Nesvorny, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Liping Qin, Sara S. Russell, Naoya Sakamoto, Maria Schonbachler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Tetsuya Yokoyama, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    SCIENCE ADVANCES   9 ( 28 )   2023.7

    　More details

    Language：English   Publishing type：Research paper (scientific journal)  

    DOI： 10.1126/sciadv.adh1003

    Web of Science

    researchmap

  • Deciphering Deep Mantle Processes from Isotopic and Highly Siderophile Element Compositions of Mantle‐Derived Rocks: Prospects and Limitations

    Katsuhiko Suzuki, Gen Shimoda, Akira Ishikawa, Tetsu Kogiso, Norikatsu Akizawa

    Core‐Mantle Co‐Evolution   75 - 101   2023.6

    　More details

    Publisher：Wiley  

    DOI： 10.1002/9781119526919.ch5

    researchmap

  • New evidence for the Ontong Java Nui hypothesis

    M. L. G. Tejada, T. Sano, T. Hanyu, A. A. P. Koppers, M. Nakanishi, T. Miyazaki, A. Ishikawa, K. Tani, S. Shimizu, K. Shimizu, B. Vaglarov, Q. Chang

    Scientific Reports   13 ( 1 )   2023.5

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

    Abstract

    The formation of the Ontong Java Nui super oceanic plateau (OJN), which is based on the model that the submarine Ontong Java Plateau (OJP), Manihiki Plateau (MP), and Hikurangi Plateau (HP) were once its contiguous fragments, could have been the largest globally consequential volcanic event in Earth’s history. This OJN hypothesis has been debated given the paucity of evidence, for example, the differences in crustal thickness, the compositional gap between MP and OJP basalts and the apparent older age of both plateaus relative to HP remain unresolved. Here we investigate the geochemical and 40Ar-39Ar ages of dredged rocks recovered from the OJP’s eastern margin. Volcanic rocks having compositions that match the low-Ti MP basalts are reported for the first time on the OJP and new ~ 96–116 Ma and 67–68 Ma 40Ar-39Ar age data bridge the temporal gap between OJP and HP. These results provide new evidence for the Ontong Java Nui hypothesis and a framework for an integrated tectonomagmatic evolution of the OJP, MP, and HP. The isotopic data imply four mantle components in the source of OJN that are also expressed in present-day Pacific hotspots sources, indicating origin from (and longevity of) the Pacific Large Low Shear-wave Velocity Province.

    DOI： 10.1038/s41598-023-33724-9

    researchmap

    Other Link： https://www.nature.com/articles/s41598-023-33724-9

  • Hydrogen Isotopic Composition of Hydrous Minerals in Asteroid Ryugu Reviewed

    Laurette Piani, Kazuhide Nagashima, Noriyuki Kawasaki, Naoya Sakamoto, Ken-ichi Bajo, Yoshinari Abe, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Wataru Fujiya, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Peter Hoppe, Gary R. Huss, Kiyohiro Ichida, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Noriko T. Kita, Kouki Kitajima, Thorsten Kleine, Shintaro Komatani, Alexander N. Krot, Ming-Chang Liu, Yuki Masuda, Kevin D. McKeegan, Mayu Morita, Kazuko Motomura, Frédéric Moynier, Izumi Nakai, Ann Nguyen, Larry Nittler, Morihiko Onose, Andreas Pack, Changkun Park, Liping Qin, Sara S. Russell, Maria Schönbächler, Lauren Tafla, Haolan Tang, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Tetsuya Yokoyama, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto

    The Astrophysical Journal Letters   946 ( 2 )   L43 - L43   2023.4

    　More details

    Publishing type：Research paper (scientific journal)   Publisher：American Astronomical Society  

    Abstract

    Rock fragments of the Cb-type asteroid Ryugu returned to Earth by the JAXA Hayabusa2 mission share mineralogical, chemical, and isotopic properties with the Ivuna-type (CI) carbonaceous chondrites. Similar to CI chondrites, these fragments underwent extensive aqueous alteration and consist predominantly of hydrous minerals likely formed in the presence of liquid water on the Ryugu parent asteroid. Here we present an in situ analytical survey performed by secondary ion mass spectrometry from which we have estimated the D/H ratio of Ryugu’s hydrous minerals, D/HRyugu, to be [165 ± 19] × 10−6, which corresponds to δDRyugu = +59 ± 121‰ (2σ). The hydrous mineral D/HRyugu’s values for the two sampling sites on Ryugu are similar; they are also similar to the estimated D/H ratio of hydrous minerals in the CI chondrites Orgueil and Alais. This result reinforces a link between Ryugu and CI chondrites and an inference that Ryugu’s samples, which avoided terrestrial contamination, are our best proxy to estimate the composition of water at the origin of hydrous minerals in CI-like material. Based on this data and recent literature studies, the contribution of CI chondrites to the hydrogen of Earth’s surficial reservoirs is evaluated to be ∼3%. We conclude that the water responsible for the alteration of Ryugu’s rocks was derived from water ice precursors inherited from the interstellar medium; the ice partially re-equilibrated its hydrogen with the nebular H2 before being accreted on the Ryugu’s parent asteroid.

    DOI： 10.3847/2041-8213/acc393

    researchmap

    Other Link： https://iopscience.iop.org/article/10.3847/2041-8213/acc393/pdf

  • The Paleoarchean Buffalo River komatiites: Progressive melting of a single large mantle plume beneath the growing Kaapvaal craton

    Netshidzivhe, T., Tappe, S., Wilson, A.H., Ishikawa, A., Viljoen, F.

    Precambrian Research   393   2023

    　More details

    Publishing type：Research paper (scientific journal)  

    DOI： 10.1016/j.precamres.2023.107071

    Scopus

    researchmap

  • Nucleosynthetic s-Process Depletion in Mo from Ryugu samples returned by Hayabusa2

    Nakanishi, N., Yokoyama, T., Ishikawa, A., Walker, R.J., Abe, Y., Al{\'e}on, J., O{'}D Alexander, C.M., Amari, S., Amelin, Y., Bajo, K.-I., Bizzarro, M., Bouvier, A., Carlson, R.W., Chaussidon, M., Choi, B.-G., Dauphas, N., Davis, A.M., Di Rocco, T., Fujiya, W., Fukai, R., Gautam, I., Haba, M.K., Hibiya, Y., Hidaka, H., Homma, H., Hoppe, P., Huss, G.R., Ichida, K., Iizuka, T., Ireland, T.R., Itoh, S., Kawasaki, N., Kita, N.T., Kitajima, K., Kleine, T., Komatani, S., Krot, A.N., Liu, M.-C., Masuda, Y., Morita, M., Motomura, K., Moynier, F., Nakai, I., Nagashima, K., Nguyen, A., Nittler, L., Onose, M., Pack, A., Park, C., Piani, L., Qin, L., Russell, S.S., Sakamoto, N., Sch{\"o}nb, a}chler, M., Tafla, L., Tang, H., Terada, K., Terada, Y., Usui, T., Wada, S., Wadhwa, M., Yamashita, K., Yin, Q.-Z., Yoneda, S., Young, E.D., Yui, H., Zhang, A.-C., Nakamura, T., Naraoka, H., Noguchi, T., Okazaki, R., Sakamoto, K., Yabuta, H., Abe, M., Miyazaki, A., Nakato, A., Nishimura, M., Okada, T., Yada, T., Yogata, K., Nakazawa, S., Saiki, T., Tanaka, S., Terui, F., Tsuda, Y., Watanabe, S.-I., Yoshikawa, M., Tachibana, S., Yurimoto, H.

    Geochemical Perspectives Letters   28   2023

    　More details

    Publishing type：Research paper (scientific journal)  

    DOI： 10.7185/geochemlet.2341

    Scopus

    researchmap

  • Author Correction: Contribution of Ryugu-like material to Earth’s volatile inventory by Cu and Zn isotopic analysis (Nature Astronomy, (2022), 7, 2, (182-189), 10.1038/s41550-022-01846-1)

    Paquet, M., Moynier, F., Yokoyama, T., Dai, W., Hu, Y., Abe, Y., Al{\'e}on, J., O?D. Alexander, C.M., Amari, S., Amelin, Y., Bajo, K.-I., Bizzarro, M., Bouvier, A., Carlson, R.W., Chaussidon, M., Choi, B.-G., Dauphas, N., Davis, A.M., Di Rocco, T., Fujiya, W., Fukai, R., Gautam, I., Haba, M.K., Hibiya, Y., Hidaka, H., Homma, H., Hoppe, P., Huss, G.R., Ichida, K., Iizuka, T., Ireland, T.R., Ishikawa, A., Ito, M., Itoh, S., Kawasaki, N., Kita, N.T., Kitajima, K., Kleine, T., Komatani, S., Krot, A.N., Liu, M.-C., Masuda, Y., McKeegan, K.D., Morita, M., Motomura, K., Nakai, I., Nagashima, K., Nesvorn?, D., Nguyen, A.N., Nittler, L., Onose, M., Pack, A., Park, C., Piani, L., Qin, L., Russell, S.S., Sakamoto, N., Sch{\"o}nb, a}chler, M., Tafla, L., Tang, H., Terada, K., Terada, Y., Usui, T., Wada, S., Wadhwa, M., Walker, R.J., Yamashita, K., Yin, Q.-Z., Yoneda, S., Young, E.D., Yui, H., Zhang, A.-C., Nakamura, T., Naraoka, H., Noguchi, T., Okazaki, R., Sakamoto, K., Yabuta, H., Abe, M., Miyazaki, A., Nakato, A., Nishimura, M., Okada, T., Yada, T., Yogata, K., Nakazawa, S., Saiki, T., Tanaka, S., Terui, F., Tsuda, Y., Watanabe, S.-I., Yoshikawa, M., Tachibana, S., Yurimoto, H.

    Nature Astronomy   7 ( 5 )   633 - 633   2023

    　More details

    Publishing type：Research paper (scientific journal)  

    DOI： 10.1038/s41550-023-01938-6

    Scopus

    researchmap

▼display all

Presentations

  • Osmium isotopic records and abundances of platinum group elements of the Cretaceous-Paleogene boundary in the Nemuro Group

    太田映, 黒田潤一郎, 高嶋礼詩, 高嶋礼詩, 星博幸, 沢田健, 池田雅志, 林圭一, 西弘嗣, 石川晃

    日本地球惑星科学連合大会予稿集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Whole-rock geochemistry of ultramafic rocks from the Kamuikotan Belt, Hokkaido, Japan: Os-Ir depletion as a signature of subduction-zone magmatism

    森英寿, 石川晃, 横山哲也, 小木曽哲, 秋澤紀克

    日本地球惑星科学連合大会予稿集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Iridium and other element concentrations in K-Pg layers on United States of America

    佐野貴司, 石本光憲, 佐藤峰南, 石川晃

    日本地球化学会年会要旨集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • 北海道白糠丘陵における白亜紀-古第三紀境界のオスミウム同位体層序

    太田映, 黒田潤一郎, 高嶋礼詩, 高嶋礼詩, 星博幸, 沢田健, 林圭一, 西弘嗣, 石川晃

    日本地質学会学術大会(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Lithospheric Mantle Beneath Polynesia: Implications from Peridotite Xenoliths of Tubuai, Austral Islands

    深瀬芙紅, 小木曽哲, 石川晃, 秋澤紀克

    日本地球化学会年会要旨集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Geochemical evolution of oceanic crust: Re-Os isochron dating and highly siderophile element concentrations in the mafic xenoliths from a petit-spot volcano

    三國和音, 三國和音, 石川晃, 石川晃, 横山哲也, 平野直人, 町田嗣樹

    日本地球化学会年会要旨集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Molybdenum isotopic compositions in Oki-Dogo Island basalts

    田村達也, 横山哲也, 石川晃, 秋澤紀克

    日本地球化学会年会要旨集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Investigating mantle evolution in the late Archean through the content of highly siderophile elements

    佐藤隆, 石川晃, 上野雄一郎, 上野雄一郎, 上野雄一郎, 横山哲也, 秋澤紀克, FIORENTINI Marco, THEBAUD Nicolas

    日本地球化学会年会要旨集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Small-scale convection and organic carbon cycle in the oceanic mantle: an approach from Aitutaki Island, Cook Islands.

    秋澤紀克, 小木曽哲, 石川晃

    日本地球化学会年会要旨集(Web)  2024 

    　More details

    Event date： 2024

    researchmap

  • Thermochemical state of the oceanic lithosphere: Constraints from peridotite xenoliths from Petit-spots.

    秋澤紀克, 秋澤紀克, 石川晃, 丹羽佑果, ALARD Olivier, GREAU Yoann, 平野直人, 町田嗣樹

    日本地球化学会年会要旨集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Osmium isotope records at the Cretaceous-Paleogene Boundary strata in Southern Hemisphere marine sediments and their significance as a chemostratigraphic correlation tool.

    黒田潤一郎, 太田映, 石川晃, 鈴木勝彦, TEJADA M.L.G., 大河内直彦

    日本地球化学会年会要旨集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Re-examination of the linkages between the Ontong Java volcanism and Cretaceous oceanic anoxic event

    松本廣直, 石川晃, 大河内直彦, 小川奈々子, 白井厚太朗, 黒田潤一郎, 鈴木勝彦

    日本地球化学会年会要旨集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Osmium isotope stratigraphy of the Cretaceous-Paleogene boundary in the Nemuro Group

    太田映, 黒田潤一郎, 高嶋礼詩, 高嶋礼詩, 星博幸, 林圭一, 鈴木勝彦, 石川晃, 西弘嗣

    日本地質学会学術大会(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Osmium isotope record in the Paleocene limestone of the Chicxulub impact basin

    佐藤峰南, 石川晃, CHRISTOPHER Lowery, SEAN Gulick, JOANNA Morgan

    日本地質学会学術大会(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Compositional mantle evolution of highly siderophile elements constrained from Phanerozoic komatiite.

    井原悠太, 石川晃, 石川晃, 横山哲也, 清水健二

    日本地球化学会年会要旨集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Evidence of fore-arc igneous activity in the behavior of highly siderophile elements: Case study of Iwanai-dake, Kamuikotan Belt, Hokkaido, Japan.

    森英寿, 石川晃, 小木曽哲, 横山哲也, 秋澤紀克

    日本地球化学会年会要旨集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • IODP Expedition 369: Osmium isotope stratigraphy and platinum group elements composition at the Cretaceous-Paleogene boundary on the Mentelle Basin off the southwest coast of Australia

    太田映, 黒田潤一郎, TEJADA Maria Luisa, 石川晃, 鈴木勝彦, 大河内直彦

    日本地球惑星科学連合大会予稿集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Molybdenum isotopic composition in igneous rocks from NE Japan

    田村達也, 横山哲也, GILL James B, 栗谷豪, 石川晃

    日本地球惑星科学連合大会予稿集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

  • Osmium isotope stratigraphy of the Cretaceous-Paleogene boundary in the Nemuro Group

    太田映, 黒田潤一郎, 石川晃, 鈴木勝彦, 高嶋礼詩

    日本地球惑星科学連合大会予稿集(Web)  2023 

    　More details

    Event date： 2023

    researchmap

▼display all

Works

  • Recycling of the Rodinia supercontinent in the Cretaceous Ontong Java Plateau?

    Ishikawa, A, Kuritani, T, Makishima, A, Nakamura, E

    2007.3

    　More details

    A rare quartz-garnet clinopyroxenite xenolith recovered from the island of Malaita in the southwest Pacific on the Ontong Java Plateau has lower 206Pb/204Pb-143Nd/144Nd and higher 87Sr/86Sr-207Pb/204Pb ratios than most oceanic basalts, providing the first conclusive evidence for an ancient crustal origin for pyroxenites within the Pacific convective mantle. Constraints from major and trace-element characteristics, the large extent of Hf-Nd isotopic decoupling, and the good agreement of Pb isotopes with the Stacey-Kramers curve, all indicate that contamination of southern Pacific mantle occurred by the subduction or delamination of Neoproterozoic granulite-like lower crust with an age of 0.5-1 Ga. This crustal recycling could have taken place around the suture of the Rodinia supercontinent, a part of which resurfaced during the mantle upwelling responsible for creating the Cretaceous Ontong Java Plateau.

    researchmap

Research Projects

  • Reevaluation of highly siderophile element excess in the mantle using oceanic peridotite

    Grant number：24K00733  2024.4 - 2027.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    　 More details

    Grant amount：\17810000 （ Direct Cost: \13700000 、 Indirect Cost：\4110000 ）

    researchmap

  • 大陸下マントルから読み解く太古代-原生代境界の地球内部変動

    Grant number：23K25965  2024.4 - 2026.3

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    石川 晃, 秋澤 紀克, 小木曽 哲

    　 More details

    Grant amount：\10790000 （ Direct Cost: \8300000 、 Indirect Cost：\2490000 ）

    researchmap

  • Investigating the origin of large projectiles by micro-sampling in the impact ejecta

    Grant number：23KK0066  2023.9 - 2027.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Fund for the Promotion of Joint International Research (International Collaborative Research)

    　 More details

    Grant amount：\20930000 （ Direct Cost: \16100000 、 Indirect Cost：\4830000 ）

    researchmap

  • 大陸下マントルから読み解く太古代-原生代境界の地球内部変動

    Grant number：23H01269  2023.4 - 2026.3

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    石川 晃, 秋澤 紀克, 小木曽 哲

    　 More details

    Grant amount：\18720000 （ Direct Cost: \14400000 、 Indirect Cost：\4320000 ）

    researchmap

  • 南半球の白亜紀-古第三紀境界：オスミウムから巨大洪水玄武岩の謎に迫る

    Grant number：22H01342  2022.4 - 2025.3

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    黒田 潤一郎, 石川 晃

    　 More details

    Grant amount：\17420000 （ Direct Cost: \13400000 、 Indirect Cost：\4020000 ）

    researchmap

  • The Cretaceous-Paleogene Boundary in the Southern Hemisphere

    Grant number：23K22613  2022.4 - 2025.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    　 More details

    Grant amount：\17420000 （ Direct Cost: \13400000 、 Indirect Cost：\4020000 ）

    researchmap

  • 太古代から原生代への地球大気変動に果たしたマントルの役割

    Grant number：19KK0091  2019.10 - 2023.3

    日本学術振興会  科学研究費助成事業  国際共同研究加速基金(国際共同研究強化(B))

    上野 雄一郎, 石川 晃, 青木 翔吾, 青山 慎之介

    　 More details

    Grant amount：\18330000 （ Direct Cost: \14100000 、 Indirect Cost：\4230000 ）

    本研究では、約24億年前に起きた大酸化事変 (GOE)に果たした固体地球変動の役割を解明することを目的として、マントルを含めた物質循環を主に硫黄同位体異常や微量元素分析等を用いて追跡する。当該年度に計画していた西オーストラリア等における野外調査は、新型コロナウイルスの感染拡大が長期化したことにより再度延期した（2022年度実施予定）。また、海洋研究開発機構で行う予定にしていた岩石試料の局所同位体分析に関しても同様の理由により遅延が生じている。一方、コマチアイトに含まれる硫黄、遷移金属元素、および強親鉄性元素の濃度測定手法の改良に取り組み、確立した手法を現有試料のコマチアイトの中でも特に古い年代（34－35億年前）を示すオーストラリア、ピルバラ地域および南アフリカ、バーバートン地域のコマチアイトに適用した結果、いずれも全岩の強親鉄性元素濃度が低くなる傾向を持ち、これが酸化還元指標となるV／Sc比と相関することが明らかになった。先行研究では、太古代の深部マントルにはレイトベニア物質（後期衝突物質）が供給されにくく、そのため太古代コマチアイトが強親鉄性元素に乏しいと考えられてきたが、本研究結果は、融解時の酸化還元状態がコマチアイトの強親鉄性元濃度変動に大きく寄与している可能性を示唆しており、従来仮説の再考を促すものである。今後より年代の若いコマチアイトの解析を進めることにより、マントルの酸化還元状態の変動要因やGOEとの因果関係についてより詳細に検討することが可能となる。

    researchmap

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

    Grant number：19H00715  2019.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    　 More details

    Grant amount：\45630000 （ Direct Cost: \35100000 、 Indirect Cost：\10530000 ）

    researchmap

  • Revealing causes of Paleozoic mass extinctions

    Grant number：19H00711  2019.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    　 More details

    Grant amount：\40560000 （ Direct Cost: \31200000 、 Indirect Cost：\9360000 ）

    researchmap

  • Detection of large upwelling in deep mantle from plume tail information

    Grant number：18H03746  2018.4 - 2023.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    　 More details

    Grant amount：\32760000 （ Direct Cost: \25200000 、 Indirect Cost：\7560000 ）

    researchmap

▼display all