An I-Xe Age 8 Myr After Solar System Formation In A Hayabusa2 Sample Records Alteration On The Parent Planetesimal Of Asteroid Ryugu.
S. A. Crowther; J. S. Cowpe; L. Fawce; J. D. Gilmour; R. Okazaki; F. Kitajima; T. Yada; S. Tachibana; K. Yogata; K. Sakamoto; H. Yurimoto; T. Nakamura; T. Noguchi; H. Naraoka; H. Yabuta; S. Watanabe; Y. Tsuda; M. Nishimura; A. Nakato; A. Miyazaki; M. Abe; T. Okada; T. Usui; M. Yoshikawa; T. Saiki; S. Tanaka; F. Terui; S. Nakazawa; H. Busemann; K. Hashizume; B. Marty; A. Meshik; M.E.I. Riebe; D. Krietsch; C. Maden; A. Ishida; P. Clay; T. Lawton; M. W. Broadley; D. J. Byrne; E. Füri; L. Zimmermann; O. Pravdivtseva; Y. N. Miura; J. Park; K. Bajo; Y. Takano; K. Yamada; S. Kawagucci; Y. Matsui; M. Yamamoto; K. Righter; S. Sakai; N. Iwata; N. Shirai; M. Inagaki; M. Ebihara; K. Nishiizumi; K. Nagao; J. I. Lee; A. Kano; M. W. Caffee; R. Uemura
Geochimica et Cosmochimica Acta, Dec. 2025, [Reviewed]

Membranes, Metals, and Resource Deposits: A New Perspective on Paleoproterozoic Life Evolution Driven by Geodynamics
Akizumi Ishida; Kouhei Sasaki; Ko Hashizume; Naoto Takahata; Yuji Sano; Takeshi Kakegawa, The early Proterozoic era (ca. 2.5 to 2.0 Ga) represents a critical period during which prokaryotes diversified and initiated their evolutionary transition toward eukaryotes, enabled by the acquisition of aerobic metabolism and efficient energy production. Recent studies have detected phosphorus and molybdenum directly from microfossils of this era, providing geochemical evidence of functional evolution related to cellular membranes and enzyme systems. Underlying this biological innovation was the global scale intensification of igneous activity, including the formation of Earth's earliest supercontinents. Enhanced hydrothermal activity at the seafloor, increased sedimentation rates, and rapid petroleum formation from sedimentary organic matter due to elevated geothermal gradients contributed not only to the formation of resource deposits, but also to significant changes in elemental cycling in the biosphere, potentially, driving early biological evolution. This presentation explores the geochemical relationship between ore formation and biological evolution offering a perspective on how Earth's dynamics influenced the trajectory of early life., GEOCHEMICAL SOCIETY OF JAPAN
Abstracts of Annual Meeting of the Geochemical Society of Japan, 2025

The Earth atmosphere‐like bulk nitrogen isotope composition obtained by stepwise combustion analyses of Ryugu return samples
Ko Hashizume; Akizumi Ishida; Ayano Chiba; Ryuji Okazaki; Kasumi Yogata; Toru Yada; Fumio Kitajima; Hisayoshi Yurimoto; Tomoki Nakamura; Takaaki Noguchi; Hikaru Yabuta; Hiroshi Naraoka; Yoshinori Takano; Kanako Sakamoto; Shogo Tachibana; Masahiro Nishimura; Aiko Nakato; Akiko Miyazaki; Masanao Abe; Tatsuaki Okada; Tomohiro Usui; Makoto Yoshikawa; Takanao Saiki; Fuyuto Terui; Satoshi Tanaka; Satoru Nakazawa; Sei‐ichiro Watanabe; Yuichi Tsuda; Michael W. Broadley; Henner Busemann, Lead, Abstract

The nitrogen isotope compositions of two samples returned from the asteroid Ryugu were determined using a stepwise combustion method, along with Ivuna (CI) and Y‐980115, a CI‐like Antarctic meteorite, as references. The two Ryugu samples A0105‐07 and C0106‐07 showed bulk δ¹⁵N values of +1.7 ± 0.5‰ and +0.2 ± 0.6‰, respectively, significantly lower than Ivuna with +36.4 ± 0.4‰, but close to Y‐980115 with +4.0 ± 0.3‰. The Ryugu samples are further characterized by C/N and ³⁶Ar/N ratios up to 3.4× and 4.9× the value of Ivuna, respectively. Among all Ryugu samples and CI chondrites, a positive correlation was observed between nitrogen concentrations and δ¹⁵N values, with samples with lower nitrogen concentrations exhibiting lower δ¹⁵N. This trend is explained by a two‐component mixing model. One component is present at a constant abundance among all CI‐related samples, with a δ¹⁵N value around 0‰ or lower. The other varies in abundance between different samples, and exhibits a δ¹⁵N value of +56 ± 4‰. The first ¹⁵N‐poor endmember is seemingly tightly incorporated into a carbonaceous host phase, whereas the ¹⁵N‐rich endmember can be mobilized and decoupled from carbon, potentially because it is in the form of ammonia. Asteroid materials with volatile compositions that are similar to those reported here for the Ryugu samples are attractive candidates for the volatile sources among Earth's building blocks., Wiley
Meteoritics and Planetary Science, 30 Apr. 2024, [Reviewed]

Microscale Simultaneous Measurement of Carbon and Nitrogen Isotopes on Natural Diamond
Akizumi Ishida; Kouki Kitajima; Ko Hashizume; Michael J. J. Spicuzza; Alexander Zaitsev; Daniel J. J. Schulze; John W. W. Valley
GEOSTANDARDS AND GEOANALYTICAL RESEARCH, Apr. 2023, [Reviewed]

Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution
Ryuji Okazaki; Bernard Marty; Henner Busemann; Ko Hashizume; Jamie D. Gilmour; Alex Meshik; Toru Yada; Fumio Kitajima; Michael Ward Broadley; David Byrne; Evelyn Füri; My E.I. Riebe; Daniela Krietsch; Colin Maden; Akizumi Ishida; Patricia Clay; Sarah A. Crowther; Lydia Fawcett; Thomas Lawton; Olga Pravdivseva; Yayoi N. Miura; Jisun Park; Ken-ichi Bajo; Yoshinori Takano; Keita Yamada; Shinsuke Kawagucci; Yohei Matsui; Mizuki Yamamoto; Kevin Righter; Saburo Sakai; Naoyoshi Iwata; Naoki Shirai; Shun Sekimoto; Makoto Inagaki; Mitsuru Ebihara; Reika Yokochi; Kunihiko Nishiizumi; Keisuke Nagao; Jong Ik Lee; Akihiro Kano; Marc W. Caffee; Ryu Uemura; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Hikaru Yabuta; Hisayoshi Yurimoto; Shogo Tachibana; Hirotaka Sawada; Kanako Sakamoto; Masanao Abe; Masahiko Arakawa; Atsushi Fujii; Masahiko Hayakawa; Naoyuki Hirata; Naru Hirata; Rie Honda; Chikatoshi Honda; Satoshi Hosoda; Yu-ichi Iijima; Hitoshi Ikeda; Masateru Ishiguro; Yoshiaki Ishihara; Takahiro Iwata; Kosuke Kawahara; Shota Kikuchi; Kohei Kitazato; Koji Matsumoto; Moe Matsuoka; Tatsuhiro Michikami; Yuya Mimasu; Akira Miura; Tomokatsu Morota; Satoru Nakazawa; Noriyuki Namiki; Hirotomo Noda; Rina Noguchi; Naoko Ogawa; Kazunori Ogawa; Tatsuaki Okada; Chisato Okamoto; Go Ono; Masanobu Ozaki; Takanao Saiki; Naoya Sakatani; Hiroki Senshu; Yuri Shimaki; Kei Shirai; Seiji Sugita; Yuto Takei; Hiroshi Takeuchi; Satoshi Tanaka; Eri Tatsumi; Fuyuto Terui; Ryudo Tsukizaki; Koji Wada; Manabu Yamada; Tetsuya Yamada; Yukio Yamamoto; Hajime Yano; Yasuhiro Yokota; Keisuke Yoshihara; Makoto Yoshikawa; Kent Yoshikawa; Shizuho Furuya; Kentaro Hatakeda; Tasuku Hayashi; Yuya Hitomi; Kazuya Kumagai; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Hiromichi Soejima; Ayako Iwamae; Daiki Yamamoto; Kasumi Yogata; Miwa Yoshitake; Ryota Fukai; Tomohiro Usui; Harold C. Connolly Jr.; Dante Lauretta; Sei-ichiro Watanabe; and Yuichi Tsuda., AAAS
Science, 24 Feb. 2023, [Reviewed]

Self-shielding effects on isotope fractionation
Hashizume K., Lead, Springer-Verlag, Berlin Heidelberg
Encyclopedia of Astrobiology, 18 Feb. 2023, [Reviewed], [Invited]

Nitrogen isotopes.
Hashizume K., Lead, Springer-Verlag, Berlin Heidelberg
Encyclopedia of Astrobiology, 18 Feb. 2023, [Reviewed], [Invited]

The noble gas and nitrogen relationship between Ryugu and carbonaceous chondrites
M.W. Broadley; D.J. Byrne; E. Füri; L. Zimmermann; B. Marty; R. Okazaki; T. Yada; F. Kitajima; S. Tachibana; K. Yogata; K. Sakamoto; H. Yurimoto; T. Nakamura; T. Noguchi; H. Naraoka; H. Yabuta; S. Watanabe; Y. Tsuda; M. Nishimura; A. Nakato; A. Miyazaki; M. Abe; T. Okada; T. Usui; M. Yoshikawa; T. Saiki; S. Tanaka; F. Terui; S. Nakazawa; H. Busemann; K. Hashizume; J.D. Gilmour; A. Meshik; M.E.I. Riebe; D. Krietsch; C. Maden; A. Ishida; P. Clay; S.A. Crowther; L. Fawcett; T. Lawton; O. Pravdivtseva; Y.N. Miura; J. Park; K. Bajo; Y. Takano; K. Yamada; S. Kawagucci; Y. Matsui; M. Yamamoto; K. Righter; S. Sakai; N. Iwata; N. Shirai; S. Sekimoto; M. Inagaki; M. Ebihara; R. Yokochi; K. Nishiizumi; K. Nagao; J.I Lee; A. Kano; M.W. Caffee; R. Uemura, Elsevier
Geochimica et Cosmochimica Acta, 26 Jan. 2023, [Reviewed]

Microbial nitrogen cycle recorded in the 3.2 Ga banded iron formation of the Fig Tree Group, Barberton, S. Africa
Hikari Saito; Akizumi Ishida; Ko Hashizume; Takeshi Kakegawa
Goldschmidt2023, Jan. 2023

First asteroid gas sample delivered by the Hayabusa2 mission: A treasure box from Ryugu
Ryuji Okazaki; Yayoi N. Miura; Yoshinori Takano; Hirotaka Sawada; Kanako Sakamoto; Toru Yada; Keita Yamada; Shinsuke Kawagucci; Yohei Matsui; Ko Hashizume; Akizumi Ishida; Michael W. Broadley; Bernard Marty; David Byrne; Evelyn Füri; Alex Meshik; Olga Pravdivtseva; Henner Busemann; My E.I. Riebe; Jamie Gilmour; Jisun Park; Ken-ichi Bajo; Kevin Righter; Saburo Sakai; Shun Sekimoto; Fumio Kitajima; Sarah A. Crowther; Naoyoshi Iwata; Naoki Shirai; Mitsuru Ebihara; Reika Yokochi; Kunihiko Nishiizumi; Keisuke Nagao; Jong Ik Lee; Patricia Clay; Akihiro Kano; Marc W. Caffee; Ryu Uemura; Makoto Inagaki; Daniela Krietsch; Colin Maden; Mizuki Yamamoto; Lydia Fawcett; Thomas Lawton; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Hikaru Yabuta; Hisayoshi Yurimoto; Yuichi Tsuda; Sei-ichiro Watanabe; Masanao Abe; Masahiko Arakawa; Atsushi Fujii; Masahiko Hayakawa; Naoyuki Hirata; Naru Hirata; Rie Honda; Chikatoshi Honda; Satoshi Hosoda; Yu-ichi Iijima; Hitoshi Ikeda; Masateru Ishiguro; Yoshiaki Ishihara; Takahiro Iwata; Kosuke Kawahara; Shota Kikuchi; Kohei Kitazato; Koji Matsumoto; Moe Matsuoka; Tatsuhiro Michikami; Yuya Mimasu; Akira Miura; Tomokatsu Morota; Satoru Nakazawa; Noriyuki Namiki; Hirotomo Noda; Rina Noguchi; Naoko Ogawa; Kazunori Ogawa; Tatsuaki Okada; Chisato Okamoto; Go Ono; Masanobu Ozaki; Takanao Saiki; Naoya Sakatani; Hiroki Senshu; Yuri Shimaki; Kei Shirai; Seiji Sugita; Yuto Takei; Hiroshi Takeuchi; Satoshi Tanaka; Eri Tatsumi; Fuyuto Terui; Ryudo Tsukizaki; Koji Wada; Manabu Yamada; Tetsuya Yamada; Yukio Yamamoto; Hajime Yano; Yasuhiro Yokota; Keisuke Yoshihara; Makoto Yoshikawa; Kent Yoshikawa; Shizuho Furuya; Kentaro Hatakeda; Tasuku Hayashi; Yuya Hitomi; Kazuya Kumagai; Akiko Miyazaki; Aiko Nakato; Masahiro Nishimura; Hiromichi Soejima; Ayako Iwamae; Daiki Yamamoto; Kasumi Yogata; Miwa Yoshitake; Ryota Fukai; Tomohiro Usui; Trevor Ireland; Harold C. Connolly Jr.; Dante S. Lauretta; and Shogo Tachibana, AAAS
Science Advances, 16 Nov. 2022, [Reviewed]

Heat-Induced Dolomitization of Amorphous Calcium Magnesium Carbonate in a CO2‑Filled Closed System
Shingo Sugawara; Wataru Fujiya; Hiroyuki Kagi; Akira Yamaguchi; and Ko Hashizume, Last, ACS Publications
ACS Omega, 09 Nov. 2022, [Reviewed]

D-depleted water isotopic measurement with a miniaturized cavity ring-down spectrometer aiming for exploration of lunar water
Murayama; J.; Yamanaka; C.; Hashizume; K. and Takigami; S., Elsevier
Sensors and Actuators A: Physical, 05 Mar. 2022, [Reviewed]

Hydrothermal Activities on C-Complex Asteroids Induced by Radioactivity
Wataru Fujiya; Hisato Higashi; Yuki Hibiya; Shingo Sugawara; Akira Yamaguchi; Makoto Kimura; Ko Hashizume, Last, Abstract

C-complex asteroids, rich in carbonaceous materials, are potential sources of Earth’s volatile inventories. They are spectrally dark resembling primitive carbonaceous meteorites, and thus, C-complex asteroids are thought to be potential parent bodies of carbonaceous meteorites. However, the substantial number of C-complex asteroids exhibits surface spectra with weaker hydroxyl absorption than water-rich carbonaceous meteorites. Rather, they best correspond to meteorites showing evidence for dehydration, commonly attributed to impact heating. Here, we report an old radiometric age of 4564.7 million years ago for Ca carbonates from the Jbilet Winselwan meteorite analogous to dehydrated C-complex asteroids. The carbonates are enclosed by a high-temperature polymorph of Ca sulfates, suggesting thermal metamorphism at >300°C subsequently after aqueous alteration. This old age indicates the early onset of aqueous alteration and subsequent thermal metamorphism driven by the decay of short-lived radionuclides rather than impact heating. The breakup of original asteroids internally heated by radioactivity should result in asteroid families predominantly consisting of thermally metamorphosed materials. This explains the common occurrence of dehydrated C-complex asteroids., American Astronomical Society
The Astrophysical Journal Letters, 01 Jan. 2022, [Reviewed]

Water and light element resources on the Moon
Ko Hashizume, Lead, Lunar Science Book Editorial Committee
Lunar Science Book, Part 1, 05 Aug. 2021, [Reviewed]

Remaining problems
Hiroshi Nagaoka; Taichi Kawamura; Makiko Ohtake; Ko Hashizume, Lunar Science Book Editorial Committee
Lunar Science Book, part 1, 05 Aug. 2021, [Reviewed]

Carbon isotopic evolution of aqueous fluids in CM chondrites: Clues from in-situ isotope analyses within calcite grains in Yamato-791198.
Fujiya W.; Aoki Y.; Ushikubo T.; Hashizume K. and Yamaguchi T., Elsevier
Geochimica et Cosmochimica Acta, Apr. 2020, [Reviewed]

Two Distinct Nitrogen Sources for Microbial Activities in the 2.0 Ga Zaonega Formation
Akizumi Ishida; Kouhei Sasaki; Ko Hashizume; Takeshi Kakegawa; Aivo Lepland
Jan. 2020

月面に供給される揮発性物質とその起源
橋爪 光, Lead, 日本惑星科学会
日本惑星科学会誌・遊星人, Apr. 2019, [Reviewed]

月内部に存在する揮発性成分
鹿山 雅裕; 橋爪 光, 日本惑星科学会
日本惑星科学会誌・遊星人, Apr. 2019, [Reviewed]

Microbial nitrogen cycle enhanced by continental input recorded in the Gunflint Formation
Ishida A.; Hashizume K.; Kakegawa T.
Geochemical Perspectives Letters, 2017, [Reviewed]

A biological switch at the ocean surface as a cause of laminations in a Precambrian iron formation
K. Hashizume; D. L. Pinti; B. Orberger; C. Cloquet; M. Jayananda; H. Soyama, Lead
EARTH AND PLANETARY SCIENCE LETTERS, Jul. 2016, [Reviewed]

Origin of laminations in BIF deciphered from N and Fe isotopes　　　　　　　　　　　　　　　
Ko Hashizume; Daniele Luigi Pinti; Beate Orberger; Mudlappa Jayananda, Lead
Goldschmidt Conference, 2013, Aug. 2013

Stepwise combustion analyses of distinct nitrogen isotopic compositions on Paleoproterozoic organic matter
Akizumi Ishida; Ko Hashizume; Takeshi Kakegawa
GEOCHEMICAL JOURNAL, 2012, [Reviewed]

Can the evolution of nitrogen cycle be traced by the N isotopic composition in mica?　　　　　　　　　　　　　　　
Daniele Luigi Pinti; Ko Hashizume
AGU 2011 Fall Meeting, Dec. 2011

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission.
Hisayoshi Yurimoto; Ken-ichi Abe; Masanao Abe; Mitsuru Ebihara; Akio Fujimura; Minako Hashiguchi; Ko Hashizume; Trevor R Ireland; Shoichi Itoh; Juri Katayama; Chizu Kato; Junichiro Kawaguchi; Noriyuki Kawasaki; Fumio Kitajima; Sachio Kobayashi; Tatsuji Meike; Toshifumi Mukai; Keisuke Nagao; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Ryuji Okazaki; Changkun Park; Naoya Sakamoto; Yusuke Seto; Masashi Takei; Akira Tsuchiyama; Masayuki Uesugi; Shigeyuki Wakaki; Toru Yada; Kosuke Yamamoto; Makoto Yoshikawa; Michael E Zolensky, Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.
Science, 26 Aug. 2011, [Reviewed]

Concurrent Births of the Organic Matter and the Oxygen Isotope Anomaly in the Solar Nebula　　　　　　　　　　　　　　　
Ko Hashizume; N. Takahata; Hiroshi Naraoka; Yuji Sano
LPSC 2011, Mar. 2011

Extreme oxygen isotope anomaly with a solar origin detected in meteoritic organics
Ko Hashizume; Naoto Takahata; Hiroshi Naraoka; Yuji Sano, Lead
NATURE GEOSCIENCE, Mar. 2011, [Reviewed]

Early life record from nitrogen isotopes
Daniele L. Pinti; Ko Hashizume, Springer Netherlands
Earliest Life on Earth: Habitats, Environments and Methods of Detection, 2011, [Reviewed], [Invited]

Biological activity and the Earth's surface evolution: Insights from carbon, sulfur, nitrogen and iron stable isotopes in the rock record
Christophe Thomazo; Daniele L. Pinti; Vincent Busigny; Magali Ader; Ko Hashizume; Pascal Philippot
COMPTES RENDUS PALEVOL, Nov. 2009, [Reviewed]

Timescales for the evolution of oxygen isotope compositions in the solar nebula
J. R. Lyons; E. A. Bergin; F. J. Ciesla; A. M. Davis; S. J. Desch; K. Hashizume; J. -E. Lee
GEOCHIMICA ET COSMOCHIMICA ACTA, Sep. 2009, [Reviewed]

Isotopic fractionation of nitrogen and carbon in Paleoarchean cherts from Pilbara craton, Western Australia: Origin of N-15-depleted nitrogen
Daniele L. Pinti; Ko Hashizume; Akiyo Sugihara; Marc Massault; Pascal Philippot
GEOCHIMICA ET COSMOCHIMICA ACTA, Jul. 2009, [Reviewed]

Two oxygen isotopic components with extra-selenial origins observed among lunar metallic grains - In search for the solar wind component
Ko Hashizume; Marc Chaussidon, Lead
GEOCHIMICA ET COSMOCHIMICA ACTA, May 2009, [Reviewed]

delta15N-delta13C covariations in organic matter through eons: Tracing the evolution of metabolic pathways　　　　　　　　　　　　　　　
Daniele Luigi Pinti; Ko Hashizume
Geochmica et Cosmochimica Acta, Jul. 2008

Mössbauer spectroscopy used for iron-oxide determination in banded iron formations: Implications for analyses on the Martian surface　　　　　　　　　　　　　　　
C. Garonne; Beate Orberger; Jorge Linares; Wagner Christiane; Richard Wirth; Ko Hashizume
Geochmica et Cosmochimica Acta, Jul. 2008

Covariation of nitrogen and iron isotopic ratios in a banded iron formation　　　　　　　　　　　　　　　
Ko Hashizume; H. Soyama; Christophe Cloque; Daniele Luigi Pinti; Virgile Rouchon; Beate Orberger; Mudlappa Jayananda
Geochmica et Cosmochimica Acta, Jan. 2008

Oxygen in the Sun
Davis A. M.; Hashizume K.; Chaussidon M.; Ireland T. R.; Allende-Prieto C.; Lambert D.
Reviews in Mineralogy and Geochemistry, 2008, [Reviewed]

Biogenic nitrogen and carbon in Fe-Mn-oxyhydroxides from an Archean chert, Marble Bar, Western Australia
Daniele L. Pinti; Ko Hashizume; Beate Orberger; Jean-Paul Gallien; Christophe Cloquet; Marc Massault
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, Feb. 2007, [Reviewed]

Biomarkers in Archaean banded iron formations from Pilbara and Dhawar Craton
Beate Orberger; Daniele Luigi Pinti; Christophe Cloque; Ko Hashizume; H. Soyama; Mudlappa Jayananda; Marc Massaul; J. P. Gallien; Richard Wirth; Virgile Rouchon; J; L. Michelo
Geochmica et Cosmochimica Acta, Aug. 2006

Search for primordial biogenic isotopic signatures of nitrogen in Archean sedimentary rocks
Ko Hashizume; A. Sugihara; Daniele Luigi Pinti; Beate Orberger; Frances Westall
Geochmica et Cosmochimica Acta, Aug. 2006

Iron isotopic composition of iron-silica layers along a profile in a single 2.9 Ga old BIF from Dhawar Craton, southern India　　　　　　　　　　　　　　　
Christophe Cloquet; Daniele Luigi Pinti; Beate Orberger; Ko Hashizume; Mudlappa Jayananda; Virgile Rouchon
CAG/MAC 2006 Montréal, May 2006

Micro-facies and origin of some Archaean Cherts (Pilbara, Australia)
Orberger B.; Rouchon V.; Westall F.; deVries S.T.; Pinti D.L.; Wagner C.; Wirth R. and Hashizume K, The Geological Society of America
The Geological Society of America Special Paper, 01 Jan. 2006, [Reviewed]

Biogeochemical cycles of sulfur and nitrogen in the Archean ocean and atmosphere.
Shen Y; Pinti D.L.; Hashizume K.
AGU Geophysical Monographs, 2006, [Reviewed]

A non-terrestrial (16)O-rich isotopic composition for the protosolar nebula
K Hashizume; M Chaussidon, Lead
NATURE, Mar. 2005, [Reviewed]

Nitrogen Isotopic Analyses at the Sub-Picomole Level Using an Ultralow Blank Laser Extraction Technique
Ko Hashizume; Bernard Marty, Lead, Elsevier Inc.
Handbook of Stable Isotope Analytical Techniques, 18 Dec. 2004, [Reviewed]

Protosolar carbon isotopic composition: Implications for the origin of meteoritic organics
K Hashizume; M Chaussidon; B Marty; K Terada, Lead
ASTROPHYSICAL JOURNAL, Jan. 2004, [Reviewed]

Nitrogen isotopes on the Moon: Archives of the solar and planetary contributions to the inner solar system
B Marty; K Hashizume; M Chaussidon; R Wieler
SPACE SCIENCE REVIEWS, 2003, [Reviewed]

Analyses of nitrogen and argon in single lunar grains: towards a quantification of the asteroidal contribution to planetary surfaces
K Hashizume; B Marty; R Wieler, Lead
EARTH AND PLANETARY SCIENCE LETTERS, Sep. 2002, [Reviewed]

Isotopic variability of nitrogen in lunar regolith - response
Hashizume K.; Chaussidon M.; Marty B.; Robert F., Lead
Science, Sep. 2001, [Reviewed]

15N-depleted nitrogen in Early Archean kerogens: clues on ancient marine chemosynthetic-based ecosystems?
Pinti D. L.; Hashizume K.
Precambrian Research, Jun. 2001, [Reviewed]

The isotopic composition of solar nitrogen and the heterogeneity of the solar system
K Hashizume; B Marty; M Chaussidon; F Robert, Lead
SOLAR AND GALACTIC COMPOSITION, 2001, [Reviewed]

The nitrogen and argon elemental and isotopic signature in >3.5 Ga metasediments: clues on the chemical state of the Archean ocean and the deep biosphere.
Pinti D. L.; Hashizume K.; Matsuda J.
Geochimica et Cosmochimica Acta, 2001, [Reviewed]

Solar Wind Record on the Moon: Deciphering Presolar from Planetary Nitrogen
Hashizume K.; Chaussidon M.; Marty B.; Robert F., Lead
Science, Nov. 2000, [Reviewed]

Nitrogen components in primitive ordinary chondrites
N Sugiura; K Kiyota; K Hashizume
METEORITICS & PLANETARY SCIENCE, May 1998, [Reviewed]

Isotope Analyses of Gaseous Elements in Extraterrestrial Samples
Ko Hashizume, Lead, 日本惑星科学会
日本惑星科学会誌・遊星人, 01 Apr. 1998, [Reviewed]

Hashizume K., Sugiura N.
Transportation of gaseous elements and their isotopes in a thermally evolving chondritic planetesimal., Lead
Meteoritics & Planetary Science, 1998, [Reviewed]

Kamijo K., Hashizume K., Matsuda J.
Noble gas constraints on the evolution of atmosphere-mantle system.
Geochimica et Cosmochimica Acta, 1998, [Reviewed]

Distinct indigenous nitrogen isotopic components co-existing in ureilites.
Yamamoto T.; Hashizume K.; Matsuda J.; Kase T., Corresponding
Meteoritics & Planetary Science, 1998, [Reviewed]

3-D Distribution of Partial Melt and Seismic Activity in the Northeastern Japan Arc
Ken-ichi Muro; Hiroki Sato; Akira Hasegawa; Ko Hashizume
火山, 01 Oct. 1997, [Reviewed]

On the Siderophile Behavior of Nitrogen and Carbon: Implications for their Inventories in the Earth
Ko Hashizume; Tomohiko Kase; Jun-ichi Matsuda; Hiroki Sato, Lead, Volcanological Society of Japan
火山, 01 Oct. 1997, [Reviewed]

Isotopically anomalous nitrogen in H-chondrite metal
K Hashizume; N Sugiura, Lead
GEOCHIMICA ET COSMOCHIMICA ACTA, Feb. 1997, [Reviewed]

Magma distribution in island arc mantle in three dimensions
H Sato; K Muro; A Hasegawa; K Hashizume
PROCEEDINGS OF THE JAPAN ACADEMY SERIES B-PHYSICAL AND BIOLOGICAL SCIENCES, Jun. 1996, [Reviewed]

COSMOGENIC NITROGEN ISOTOPIC DISEQUILIBRIUM OBSERVED IN METEORITES
N SUGIURA; K HASHIZUME; Y MIURA; K KIYOTA; S ZASHU
METEORITICS, Nov. 1995, [Reviewed]

Nitrogen Isotope Cosmochemistry
Ko Hashizume, Lead
The Japanese Society for Planetary Sciences, Planetary People, 01 Oct. 1995, [Reviewed]

NITROGEN ISOTOPES IN BULK ORDINARY CHONDRITES
K HASHIZUME; N SUGIURA, Lead
GEOCHIMICA ET COSMOCHIMICA ACTA, Oct. 1995, [Reviewed]

Reply to Comment on “Measurement of cosmogenic nitrogen using a static mass-spectrometry system and its implication”
Hashizume K.; Sugiura N., Lead
Geochimica et Cosmochimica Acta, 1993, [Reviewed], [Invited]

Sugiura N., Hashizume K.
Nitrogen isotope anomalies in primitive ordinary chondrites.
Earth and Planetary Science Letters, 1992, [Reviewed]

Hashizume K., Sugiura N.
Measurement of cosmogenic nitrogen using a static mass-spectrometry system and its implication., Lead
Geochimica et Cosmochimica Acta, 1992, [Reviewed]

Sugiura N., Hashizume K.
Heavy nitrogen in the Yamato-74191 and the heterogeneity of the primitive solar nebula.
Proceedings of the NIPR Symposium on Antarctic Meteorites, 1991, [Reviewed]

Hashizume K., Sugiura N.
Precise measurement of nitrogen isotopic composition using a quadrupole mass spectrometer., Lead
Journal of the Mass Spectrometry Society of Japan, 1990, [Reviewed]

Membranes, Metals, and Resource Deposits: A New Perspective on Paleoproterozoic Life Evolution Driven by Geodynamics
石田章純; 笹木晃平; 橋爪光; 高畑直人; 佐野有司; 掛川武
日本地球化学会年会要旨集(Web), 2025

〔Major achievements〕地球大気のふるさと-リュウグウ試料の揮発性成分分析から見えたその手がかり　　　　　　　　　　　　　　　
橋爪 光・岡崎隆司
化学と工業, 11 Feb. 2024
Lead

Nitrogen isotope compositions of ca. 2.0 Ga Zaonega Formation in Russia: their constraints on Paleoproterozoic oceanic environments and microbial activities
笹木晃平; 石田章純; 橋爪光; 掛川武
日本地球惑星科学連合大会予稿集(Web), 2021

Heterogeneity in nitrogen source for microbial activity recorded in 2.0 Ga Zaonega Formation, NW Russia
石田章純; 笹木晃平; 橋爪光; 掛川武; LEPLAND Aivo
日本地球惑星科学連合大会予稿集(Web), 2020

S12-03 イトカワ母天体の熱進化(口頭セッション12:はやぶさ,口頭発表)
圦本 尚義; 中村 智樹; 伊藤 正一; 坂本 直哉; 阿部 憲一; 橋口 未奈子; 片山 樹里; 加藤 千図; 川崎 教行; 小林 幸雄; 女池 竜二; 朴 昌根; 武井 将志; 若木 重行; 山本 広佑; 橋爪 光; 土山 明; 瀬戸 雄介; 長尾 敬介; 野口 高明; 海老原 充; 奈良岡 浩; 北島 富美雄; 岡崎 隆司; Ireland T.R.; Zolensky M.E.; 阿部 正真; 藤村 彰夫; 川口 淳一郎; 向井 利典; 上椙 真之; 矢田 達; 吉川 真
日本惑星科学会秋期講演会予稿集, 23 Oct. 2011

OXYGEN AND MAGNESIUM ISOTOPIC COMPOSITIONS OF ASTEROID 25143 ITOKAWA RETURNED BY THE HAYABUSA MISSION
H. Yurimoto; K. Abe; M. Abe; M. Ebihara; A. Fujimura; M. Hashiguchi; K. Hashizume; T. R. Ireland; S. Itoh; J. Katayama; C. Kato; J. Kawaguchi; N. Kawasaki; F. Kitajima; S. Kobayashi; T. Meike; T. Mukai; K. Nagao; T. Nakamura; H. Naraoka; T. Noguchi; R. Okazaki; C. Park; N. Sakamoto; Y. Seto; M. Takei; A. Tsuchiyama; M. Uesugi; S. Wakaki; T. Yada; K. Yamamoto; M. Yoshikawa; M. E. Zolensky
METEORITICS & PLANETARY SCIENCE, Jul. 2011

段階燃焼法によって明らかにされた初期原生代有機物窒素同位体比の二相性
石田章純; 橋爪光; 掛川武
日本地球化学会年会講演要旨集, 2011

小惑星イトカワの酸素同位体組成,²⁶Al初生存在度,微量元素組成
YURIMOTO HISAYOSHI; ITO SHOICHI; SAKAMOTO NAOYA; KOBAYASHI SACHIO; HASHIZUME KO; TSUCHIYAMA AKIRA; SETO YUSUKE; IRELAND T. R; ZOLENSKY M; NAKAMURA TOMOKI; NOGUCHI TAKAAKI; NAGAO KEISUKE; EBIHARA MITSURU; NARAOKA HIROSHI; OKAZAKI RYUICHI; KITAJIMA FUMIO; MUKAI TOSHIFUMI; FUJIMURA AKIO; ABE MASANAO; YADA TOORU; UESUGI MASAYUKI; YOSHIKAWA MAKOTO; KAWAGUCHI JUN'ICHIRO
日本地球化学会年会講演要旨集, 2011

In-situ ion microprobe U-Pb dating of volcanic/impact spherules from Apollo17 lunar sample
K Terada; T Saiki; Hidaka, I; K Hashizume; Y Sano
GEOCHIMICA ET COSMOCHIMICA ACTA, Sep. 2003

107 Nitrogen in planetesimals during their thermal evolution : a clue to the estimate of the terrestrial nitrogen inventory
橋爪 光
Abstracts Fall Meeting of the Japanese Society for Planetary Sciences, 15 Oct. 1993

生命起源の事典　　　　　　　　　　　　　　　
橋爪 光, Single work
朝倉書店, Apr. 2024

Water and light element resources on the Moon. In Lunar Science Book, Part 1
Hashizume; K., Contributor
Lunar Science Book Editorial Committee, 05 Aug. 2021, [Reviewed]

Remaining problems, In Lunar Science Book, part 1.
Hiroshi Nagaoka; Taichi Kawamura; Makiko Ohtake; Ko Hashizume, Contributor
Lunar Science Book Editorial Committee, 05 Aug. 2021, [Reviewed]

Exploration of Lunar Water by Lunar Thermogravimetric Analyzer (LTGA) Onboard LUPEX Rover　　　　　　　　　　　　　　　
Ryusuke NISHITANI; Shio INOUE; Aoi OGISHIMA; Yoshiaki ISHIHARA; Jun NAKAJIMA; Hideaki HOTTA; Hiroyasu MIZUNO; Takeshi HOSHINO; Dai ASOH; Ko HASHIZUME
AOGS 23rd Annual Meeting, 05 Aug. 2026
20260802, 20260807

Nitrogen isotope evidence for biogenic nitrogen fixation in the Early Archean　　　　　　　　　　　　　　　
Kohei Sasaki; Akizumi Ishida; Takeshi Kakegawa; Kenichiro Sugitani; Ko Hashizume; Naoto Takahata
JpGU-AGU Joint Meeting 2026, 24 May 2026
20260524, 20260529

Thermogravimetric measurements of hydrated simulant for LUPEX’s Lunar Thermogravimetric Analyzer (LTGA)　　　　　　　　　　　　　　　
OGISHIMA Aoi, NISHITANI Ryusuke, ISHIHARA Yoshiaki, INOUE Shio, MIZUNO Hiroyasu, HOSHINO Takeshi, HASHIZUME Ko, KAYAMA Masahiro
JpGU-AGU Joint Meeting 2026, 24 May 2026
20260524, 20260529

1.49μm帯レーザーを用いたCRDSによるアンモニア同位体測定　　　　　　　　　　　　　　　
滿田 龍一; 山中 千博; 橋爪 光
レーザー学会学術講演会第46回年次大会, 15 Jan. 2026
20260113, 20260115

二つの月面水素資源に関する比較研究　　　　　　　　　　　　　　　
橋爪 光
第69回宇宙科学技術連合講演会, 27 Nov. 2025

月面で推薬を産むための水資源の獲得　　　　　　　　　　　　　　　
佐藤 崇徳; 田中 健一郎; 上垣 雄也; 成松 義人; 新居正章; 永瀬 睦; 黒須 聡; 白津 英仁; 村田 明弘; 橋爪 光; 鹿山雅裕
第69回宇宙科学技術連合講演会, 27 Nov. 2025

月極域探査 LUPEX搭載REIWAの開発状況　　　　　　　　　　　　　　　
西谷隆介; 石原 吉明; 井上 志生; 中島 潤; 相田 真里; 神崎 千沙子; 小野 渉; 市田 啓希; 江崎 和之; 橋爪 光; 齋藤 義文; 山中 千博; 水野 浩靖; 星野 健; 麻生 大
第69回宇宙科学技術連合講演会, 27 Nov. 2025

Nitrogen isotope variations among Ryugu and Bennu bulk samples caused by hydrothermal alterations　　　　　　　　　　　　　　　
Ko Hashizume; Taiki Ito; Ryuji Okazaki; Yuma Enokido; Wataru Fujiya; Akizumi Ishida; Hiroshi Naraoka; Takaaki Noguchi; Kanako Sakamoto; Yuji Sano; Shogo Tachibana
12th Symposium of Solar System Materials, 13 Nov. 2025

南アフリカ・ムーディーズ層群中の縞状鉄鉱層の鉱物学的・地球化学的研究　　　　　　　　　　　　　　　
石成慶大; 石田章純; 橋爪光; 掛川武
日本地球化学会第72回年会, 17 Sep. 2025

膜、金属、資源鉱床: 地球ダイナミクスが駆動した初期原生代生命進化への新たな視座　　　　　　　　　　　　　　　
石田章純; 笹木晃平; 橋爪光; 高畑直人; 佐野有司; 掛川武
日本地球化学会第72回年会, 17 Sep. 2025

月極域探査（LUPEX）の観測運用-着陸地点候補(CR-1）領域の探査領域候補の再選定-　　　　　　　　　　　　　　　
石原吉明; 諸田智克; 鹿山雅裕; 橋爪光; 井上博夏; 西谷隆介; 大竹真紀子; アウトプットデータ創出チーム
日本惑星科学会2025 年秋季講演会, 03 Sep. 2025

月面極域水の濃集過程　　　　　　　　　　　　　　　
橋爪 光
日本惑星科学会2025 年秋季講演会, 03 Sep. 2025

Terrestrial 40Ar implantation into lunar regolith via Earth wind　　　　　　　　　　　　　　　
Hiroya Abe; Akifumi Nakayama; Ryoya Sakata; Kanako Seki; Shotaro Sakai; Hiroyuki; Shinagawa; Naoki Terada; Ko Hashizume; Hidenori Genda
Japan Geoscience Union Meeting 2025, 30 May 2025
20250525, 20250530

Isotopic Measurement of Ammonia Using Cavity Ring-Down Spectroscopy (CRDS) with a 1.49 μm Laser　　　　　　　　　　　　　　　
Ryuichi Mitsuda; Chihiro YAMANAKA; Ko HASHIZUME
Japan Geoscience Union Meeting 2025, 30 May 2025
20250525, 20250530

Water trapped at illuminated-polar region of Moon - the role of gardening effect　　　　　　　　　　　　　　　
Ko HASHIZUME
Japan Geoscience Union Meeting 2025, 30 May 2025
20250525, 20250530

月極域水の濃集原理　　　　　　　　　　　　　　　
橋爪 光
月極域探査ワークショップその６ ～人類の持続的な月面活動を目指して：探査計画とデータの有効活用法～, 16 Apr. 2025
20250416, 20250417

地球風による月面への40Arの供給：アポロサンプルと月隕石の対比　　　　　　　　　　　　　　　
阿 部 広 也; 中 山 陽 史; 坂 田 遼 弥; 関 華 奈 子; 堺 正 太 郎; 品 川 裕 之; 寺 田 直 樹; 橋 爪 光; 玄 田 英
日本惑星科学会2024年秋季講演会, 26 Sep. 2024
20240924, 20240926

CRDS、月へ行く　　　　　　　　　　　　　　　
橋爪 光
湿度、水分計測・センサ研究会創立40周年記念事業講演会, 26 Jul. 2024, [Invited]

地球を飛び出せ！ 月・小惑星の揮発性成分同位体分析　　　　　　　　　　　　　　　
橋爪 光
第72回質量分析総合討論会, 10 Jun. 2024, [Invited]

Primary anhydrous minerals in CI chondrites and Ryugu samples: Their similarities and the relationship to Ca-carbonate　　　　　　　　　　　　　　　
Taro Ando; Takaaki Noguchi; Yohei Igami; Akira Yamaguchi; Toru Matsumoto; Ko Hashizume; Takayuki Ushikubo; Shoichi Itoh
JpGU2024, 26 May 2024
20240526, 20240531

Water Analysis Module with Direct Measurement　　　　　　　　　　　　　　　
M. Shinohara; M. Nagase; H. Hotta; N. Tanigawa; N. Suzuki; S. Kurosu; A. Murata; Y. Akutsu; S. Kawai; K. Hashizume; H. Miyamoto; M. Kayama
7th Global Moon Village Workshop & Symposium, 07 Dec. 2023

月における水の科学検討と資源活用　　　　　　　　　　　　　　　
鹿山雅裕; 橋爪光; 宮本英昭; 戒能 碩人; 鈴木直志
第67回宇宙科学技術連合講演会, 18 Oct. 2023

月面水の濃集機構　　　　　　　　　　　　　　　
橋爪 光; 鹿山 雅裕; 宮本 英昭; 鈴木 直志
第67回宇宙科学技術連合講演会, 18 Oct. 2023

月表層浅部の水資源分布マップ生成シナリオ　　　　　　　　　　　　　　　
宮本 英昭; 鈴木 直志; 鹿山 雅裕; 橋爪 光; 堀田 任晃; 白津 英仁
第67回宇宙科学技術連合講演会, 17 Oct. 2023

月極域探査機(LUPEX) プロジェクト LTGA の開発状況　　　　　　　　　　　　　　　
西谷隆介; 野村麗子; 下村琢磨; 石原吉明; 水野浩靖; 小野渉; 江崎和之; 松枝太郎; 大竹真紀子; 橋爪光
第67回宇宙科学技術連合講演会, 17 Oct. 2023

月の水、太陽系の水　　　　　　　　　　　　　　　
橋爪 光
機械学会宇宙工学部門「宇宙サロン」, 14 Oct. 2023, [Invited]

月極域探査機プロジェクト の検討状況 水の存在量および存在形態の推定に向けた 水資源分析計(REIWA)の開発　　　　　　　　　　　　　　　
西谷隆介; 下村琢磨; 石原吉明; 野村麗子; 水野浩靖; 大竹真紀子; 橋爪光; 齋藤義文; 山中千博; 小野渉; 江崎和之; 市田啓希
日本惑星科学会2023年秋季講演会, 11 Oct. 2023

CRDS によるアンモニアガス中の 15N／14N 比　　　　　　　　　　　　　　　
山中 千博; 橋爪 光; 村山 純平
第41回レーザセンシングシンポジウム, 07 Sep. 2023

月極域日照地域における表土内水濃集過程　　　　　　　　　　　　　　　
橋爪 光
日本地球惑星科学連合2023年大会, 26 May 2023

南極産CIコンドライト隕石中の窒素同位体段階燃焼分析から推察する CIコンドライト隕石母天体中の変成作用　　　　　　　　　　　　　　　
千葉 文乃; 笠原 航河; 橋爪 光
日本地球惑星科学連合2023年大会, 25 May 2023

The nitrogen cycle in the lithosphere-biosphere in 3.2 Ga: Constraints from banded iron formations of Fig Tree Group, Barberton, S. Africa.　　　　　　　　　　　　　　　
H. Saito; A. Ishida; K. Hashizume; T. Kakegawa
The 47th Annual Meeting of The Society for the Study of the Origin and Evolution of Life Japan, 28 Mar. 2023

Nitrogen isotopes in Ryugu return samples revealed by the stepwise combustion analysis, in comparison with CI falls and Antarctic finds　　　　　　　　　　　　　　　
Ko Hashizume; Akizumi Ishida; Ayano Chiba; Ryuji Okazaki; Toru Yada; Fumio Kitajima; Hisayoshi Yurimoto; Tomoki Nakamura; Hiroshi Naraoka; Takaaki Noguchi; Hikaru Yabuta; Shogo Tachibana; Sei-ichiro Watanabe; Kanako Sakamoto and Yuichi Tsuda
The 9th Hayabusa Symposium, 16 Nov. 2022
20221114, 20221116