Ph. D., The University of Tokyo, Mar. 2005

Planetary Science

SIMS

Isotope Geochemistry

Meteorite

Natural sciences, Space and planetary science

Apr. 2023 - Present
Kochi University, Guest Professor

Sep. 2013 - Present
JAMSTEC, Kochi Institute for Core Sample Research, Research Scientist

Jul. 2008 - Aug. 2013
University of Wisconsin-Madison, Assistant Scientist

Jun. 2006 - Jun. 2008
University of Wisconsin-Madison, Postdoctral Research Associate

Jun. 2005 - May 2006
Arizona State University, Postdoctral Research Associate

Apr. 2000 - Mar. 2001
Ministry of the Environment, Goverment of Japan, Engineering Official

Apr. 2001 - Mar. 2005, University of Tokyo, Gradeuate School of Science, Department of Earth and Planetary Science

Apr. 1997 - Mar. 2000, University of Tokyo, Gradeuate School of Science, Department of Earth and Planetary Physics

Apr. 1995 - Mar. 1997, University of Tokyo, Faculty of Science, Department of Earth and Planetary Physics

Mar. 2016 - Mar. 2022
全国共同利用課題選定委員, 高知大学海洋コア総合研究センター

Alexey Kotov; Noriyoshi Tsuchiya; Satoshi Okumura; Masao Ban; Masaoki Uno; Isoji Miyagi; Kenji Shimizu; Takayuki Ushikubo; Geri Agroli; Shumpei Yoshimura; Manzshir Bayarbold
Magmatic evolution and timescales of the Naruko caldera system (NE Honshu): Insight from orthopyroxene and quartz mineral zoning
Journal of Volcanology and Geothermal Research, Nov. 2025
467, 108415, 108415
[Reviewed]

Yulina V. Hane; Ryoshiro Wakiya; Takayuki Ushikubo; Yuki Nozoe; Shingo Kimura
Reconstructing water temperatures and depths experienced during the newly hatched larval stage of the tropical eel Anguilla marmorata using otolith oxygen isotope analysis
Fisheries Science, 22 Feb. 2025
[Reviewed]

Fumihiro Matsu'ura; Yusuke Sawaki; Tsuyoshi Komiya; Jian Han; Shigenori Maruyama; Takayuki Ushikubo; Kenji Shimizu; Yuichiro Ueno
Oceanic and Sedimentary Microbial Sulfur Cycling Controlled by Local Organic Matter Flux During the Ediacaran Shuram Excursion in the Three Gorges Area, South China
Geobiology, 19 Sep. 2024
22, 5
[Reviewed]

Takaaki Noguchi; Daisuke Nakashima; Takayuki Ushikubo; Wataru Fujiya; Noriaki Ohashi; John P. Bradley; Tomoki Nakamura; Noriko T. Kita; Peter Hoppe; Hidemi Ishibashi; Makoto Kimura; Naoya Imae
Chondrule-like objects and a Ca-Al-rich inclusion from comets or comet-like icy bodies
Geochimica et Cosmochimica Acta, Sep. 2024
381, 131, 155
[Reviewed]

Yves Moussallam; William Henry Towbin; Terry Plank; Hélène Bureau; Hicham Khodja; Yunbin Guan; Chi Ma; Michael B. Baker; Edward M. Stolper; Fabian U. Naab; Brian D. Monteleone; Glenn A. Gaetani; Kenji Shimizu; Takayuki Ushikubo; Hyun Joo Lee; Shuo Ding; Sarah Shi; Estelle F. Rose‐Koga
ND70 Series Basaltic Glass Reference Materials for Volatile Element (H₂O, CO₂, S, Cl, F) Measurement and the C Ionisation Efficiency Suppression Effect of Water in Silicate Glasses in SIMS
Geostandards and Geoanalytical Research, 25 Jul. 2024
48, 3, 637, 660
[Reviewed]

Yuka Inagaki; Yoshiyuki Ishitani; Akihiro Tame; Katsuyuki Uematsu; Naotaka Tomioka; Takayuki Ushikubo; Yurika Ujiié
Foraminiferal detoxification breakdown induced by fatal levels of TiO2 nanoparticles
Frontiers in Marine Science, 01 Jul. 2024
11, 1381247
[Reviewed]

Daisuke Nakashima; Takaaki Noguchi; Takayuki Ushikubo; Makoto Kimura; Noriko Kita
Oxygen isotope study of the Asuka-881020 CH chondrite II: Porphyritic chondrules
Geochimica et Cosmochimica Acta, May 2024
373, 292, 307
[Reviewed]

Nozaki, T.; Nagase, T.; Ushikubo, T.; Shimizu, K.; Komuro, K.
In situ sulfur isotope analysis of pyrite from the Ezuri Kuroko-type volcanogenic massive sulfide deposit, northeastern Japan: Contribution of microbial sulfate reduction to initial sulfide mineralization
Resource Geology, Jan. 2024
74, 1, e12328
[Reviewed]

Sota Arakawa; Daiki Yamamoto; Takayuki Ushikubo; Hiroaki Kaneko; Hidekazu Tanaka; Shigenobu Hirose; Taishi Nakamoto
Oxygen isotope exchange between molten silicate spherules and ambient water vapor with nonzero relative velocity: Implication for chondrule formation environment
Icarus, Nov. 2023
405, 115690, 115690
[Reviewed]

Mingming Zhang; Kohei Fukuda; Michael J. Spicuzza; Guillaume Siron; Adriana Heimann; Alex J. Hammerstrom; Noriko T. Kita; Takayuki Ushikubo; John W. Valley
SIMS matrix effects in oxygen isotope analysis of olivine and pyroxene: Application to Acfer 094 chondrite chondrules and reconsideration of the primitive chondrule minerals (PCM) line
Chemical Geology, 05 Oct. 2022
608
[Reviewed]

Maximilien Bôle; Takayuki Ushikubo; Rie S. Hori; Peter O. Baumgartner; Yuki Nakai; Masayuki Ikeda
Si isotope ratio of radiolaria across Triassic–Jurassic transition in a pelagic deep-sea bedded chert (Inuyama, Japan)
Global and Planetary Change, Aug. 2022
215
[Reviewed]

Masataka Kawaguchi; Kenneth T Koga; Estelle Rose-Koga; Kenji Shimizu; Takayuki Ushikubo; Akira Yoshiasa
Sulfur isotope and trace element systematics in arc magmas: seeing through the degassing via a melt inclusion study of Kyushu Island volcanoes, Japan
Journal of Petrology, 01 Jul. 2022
[Reviewed]

Jia Liu; Chunhui Tao; Jianping Zhou; Kenji Shimizu; Wei Li; Jin Liang; Shili Liao; Takeshi Kuritani; Etienne Deloule; Takayuki Ushikubo; Mitsuhiro Nakagawa; Weifang Yang; Guoyin Zhang; Yunlong Liu; Chuanwei Zhu; Hao Sun; Jingjun Zhou
Water enrichment in the mid-ocean ridge by recycling of mantle wedge residue
Earth and Planetary Science Letters, Apr. 2022
584, 117455, 117455
[Reviewed]

Fukuda, K.; Tenner, T.J.; Kimura, M.; Tomioka, N.; Siron, G.; Ushikubo, T.; Chaumard, N.; Hertwig, A.T.; Kita, N.T.
A temporal shift of chondrule generation from the inner to outer Solar System inferred from oxygen isotopes and Al-Mg chronology of chondrules from primitive CM and CO chondrites
Geochimica et Cosmochimica Acta, Apr. 2022
322, 194, 226
[Reviewed]

MacPherson, G.J.; Krot, A.N.; Kita, N.T.; Bullock, E.S.; Nagashima, K.; Ushikubo, T.; Ivanova, M.A.
The formation of Type B CAIs: Evolution from Type A CAIs
Geochimica et Cosmochimica Acta, Mar. 2022
321, 343, 374
[Reviewed]

Kenji Shimizu; Takayuki Ushikubo; Takeshi Kuritani; Naoto Hirano; Shigeru Yamashita
Modification for the matrix effect in SIMS-derived water contents of silicate glasses
GEOCHEMICAL JOURNAL, 2022
56, 6, 223, 230
[Reviewed]

Yulina Hane; Takayuki Ushikubo; Yusuke Yokoyama; Yosuke Miyairi; Shingo Kimura
Natal origin of Pacific bluefin tuna Thunnus orientalis determined by SIMS oxygen isotope analysis of otoliths
PloS one, 2022
17, 8, e0272850
[Reviewed]

Takeshi Kuritani; Kenji Shimizu; Takayuki Ushikubo; Qun Ke Xia; Jia Liu; Mitsuhiro Nakagawa; Hajime Taniuchi; Eiichi Sato; Nobuo Doi
Tracing the subducting Pacific slab to the mantle transition zone with hydrogen isotopes
Scientific Reports, Dec. 2021
11, 1
[Reviewed]

Takeshi Kuritani; Eiichi Sato; Keiji Wada; Akiko Matsumoto; Mitsuhiro Nakagawa; Dapeng Zhao; Kenji Shimizu; Takayuki Ushikubo
Conditions of magma generation at the Me-akan volcano, northern Japan
Journal of Volcanology and Geothermal Research, Sep. 2021
417
[Reviewed]

Tatsuo Nozaki; Toshiro Nagase; Takayuki Ushikubo; Kenji Shimizu; Jun-ichiro Ishibashi
Microbial sulfate reduction plays an important role at the initial stage of subseafloor sulfide mineralization
Geology, 01 Feb. 2021
49, 2, 222, 227
[Reviewed]

Masataka Kawaguchi; Toshiaki Hasenaka; Kenneth T. Koga; Estelle F. Rose-Koga; Atsushi Yasuda; Natsumi Hokanishi; Yasushi Mori; Kenji Shimizu; Takayuki Ushikubo
Persistent gas emission originating from a deep basaltic magma reservoir of an active volcano: the case of Aso volcano, Japan
Contributions to Mineralogy and Petrology, Jan. 2021
176, 1
[Reviewed]

Ushikubo, T.; Kimura, M.
Oxygen-isotope systematics of chondrules and olivine fragments from Tagish Lake C2 chondrite: Implications of chondrule-forming regions in protoplanetary disk
Geochimica et Cosmochimica Acta, 2021
293, 328, 343
[Reviewed]
Lead, Corresponding

Hane, Y.; Kimura, S.; Yokoyama, Y.; Miyairi, Y.; Ushikubo, T.; Ishimura, T.; Ogawa, N.; Aono, T.; Nishida, K.
Reconstruction of temperature experienced by Pacific bluefin tuna Thunnus orientalis larvae using SIMS and microvolume CF-IRMS otolith oxygen isotope analyses
Marine Ecology Progress Series, 2020
649, 175, 188
[Reviewed]

Hamada, M.; Iwamori, H.; Brandl, P.A.; Ushikubo, T.; Shimizu, K.; Ito, M.; Li, H.; Savov, I.P.
Temporal Evolution of Proto-Izu-Bonin-Mariana Arc Volcanism over 10 Myr: Constraints from Statistical Analysis of Melt Inclusion Compositions
Journal of Petrology, 2020
61, 1
[Reviewed]

Nakashima, D.; Kimura, M.; Yamada, K.; Noguchi, T.; Ushikubo, T.; Kita, N.
Oxygen isotope study of the Asuka-881020 CH chondrite I: Non-porphyritic chondrules
Geochimica et Cosmochimica Acta, 2020
290, 180, 200
[Reviewed]

Hanyu, T.; Yamamoto, J.; Kimoto, K.; Shimizu, K.; Ushikubo, T.
Determination of total CO2 in melt inclusions with shrinkage bubbles
Chemical Geology, 2020
557
[Reviewed]

Fujiya, W.; Aoki, Y.; Ushikubo, T.; Hashizume, K.; Yamaguchi, A.
Carbon isotopic evolution of aqueous fluids in CM chondrites: Clues from in-situ isotope analyses within calcite grains in Yamato-791198
Geochimica et Cosmochimica Acta, 2020
274, 246, 260
[Reviewed]

Shimizu, K.; Ushikubo, T.; Murai, T.; Matsu'Ura, F.; Ueno, Y.
In situ analyses of hydrogen and sulfur isotope ratios in basaltic glass using SIMS
Geochemical Journal, 2019
53, 3, 195, 207
[Reviewed]

Zeb Page, F.; Cameron, E.M.; Flood, C.M.; Dobbins, J.W.; Spicuzza, M.J.; Kitajima, K.; Strickland, A.; Ushikubo, T.; Mattinson, C.G.; Valley, J.W.
Extreme oxygen isotope zoning in garnet and zircon from a metachert block in mélange reveals metasomatism at the peak of subduction metamorphism
Geology, 2019
47, 7, 655, 658
[Reviewed]

Fujiya, W.; Hoppe, P.; Ushikubo, T.; Fukuda, K.; Lindgren, P.; Lee, M.R.; Koike, M.; Shirai, K.; Sano, Y.
Migration of D-type asteroids from the outer Solar System inferred from carbonate in meteorites
Nature Astronomy, 2019
3, 10, 910, 915
[Reviewed]

Tenner, T.J.; Nakashima, D.; Ushikubo, T.; Tomioka, N.; Kimura, M.; Weisberg, M.K.; Kita, N.T.
Extended chondrule formation intervals in distinct physicochemical environments: Evidence from Al-Mg isotope systematics of CR chondrite chondrules with unaltered plagioclase
Geochimica et Cosmochimica Acta, 2019
260, 133, 160
[Reviewed]

Kuritani, T.; Xia, Q.-K.; Kimura, J.-I.; Liu, J.; Shimizu, K.; Ushikubo, T.; Zhao, D.; Nakagawa, M.; Yoshimura, S.
Buoyant hydrous mantle plume from the mantle transition zone
Scientific Reports, 2019
9, 1
[Reviewed]

Hertwig, A.T.; Kimura, M.; Ushikubo, T.; Defouilloy, C.; Kita, N.T.
The ²⁶ Al- ²⁶ Mg systematics of FeO-rich chondrules from Acfer 094: Two chondrule generations distinct in age and oxygen isotope ratios
Geochimica et Cosmochimica Acta, 2019
253, 111, 126
[Reviewed]

Hanyu, T.; Shimizu, K.; Ushikubo, T.; Kimura, J.-I.; Chang, Q.; Hamada, M.; Ito, M.; Iwamori, H.; Ishikawa, T.
Tiny droplets of ocean island basalts unveil Earth’s deep chlorine cycle
Nature Communications, 2019
10, 1, 60, 60
[Reviewed]

Lepot, K.; Williford, K.H.; Philippot, P.; Thomazo, C.; Ushikubo, T.; Kitajima, K.; Mostefaoui, S.; Valley, J.W.
Extreme ¹³C-depletions and organic sulfur content argue for S-fueled anaerobic methane oxidation in 2.72 Ga old stromatolites
Geochimica et Cosmochimica Acta, 2019
244, 522, 547
[Reviewed]

Helser, T.; Kastelle, C.; Crowell, A.; Ushikubo, T.; Orland, I.J.; Kozdon, R.; Valley, J.W.
A 200-year archaeozoological record of Pacific cod (Gadus macrocephalus) life history as revealed through ion microprobe oxygen isotope ratios in otoliths
Journal of Archaeological Science: Reports, 2018
21, 1236, 1246
[Reviewed]

Shirai, K.; Otake, T.; Amano, Y.; Kuroki, M.; Ushikubo, T.; Kita, N.T.; Murayama, M.; Tsukamoto, K.; Valley, J.W.
Temperature and depth distribution of Japanese eel eggs estimated using otolith oxygen stable isotopes
Geochimica et Cosmochimica Acta, 2018
236, 373, 383
[Reviewed]

Hamada, M.; Kimura, J.-I.; Chang, Q.; Hanyu, T.; Ushikubo, T.; Shimizu, K.; Ito, M.; Ozawa, T.; Iwamori, H.
High-precision in situ analysis of Pb isotopes in melt inclusions by LA-ICP-MS and application of independent component analysis
Geochemical Journal, 2018
52, 1, 69, 74
[Reviewed]

Williams, C.D.; Ushikubo, T.; Bullock, E.S.; Janney, P.E.; Hines, R.R.; Kita, N.T.; Hervig, R.L.; MacPherson, G.J.; Mendybaev, R.A.; Richter, F.M.; Wadhwa, M.
Thermal and chemical evolution in the early solar system as recorded by FUN CAIs: Part I – Petrology, mineral chemistry, and isotopic composition of Allende FUN CAI CMS-1
Geochimica et Cosmochimica Acta, 2017
201, 25, 48
[Reviewed]

Shimizu, K.; Ushikubo, T.; Hamada, M.; Itoh, S.; Higashi, Y.; Takahashi, E.; Ito, M.
H2O, CO2, F, S, Cl, and P2O5 analyses of silicate glasses using SIMS: Report of volatile standard glasses
Geochemical Journal, 2017
51, 4, 299, 313
[Reviewed]

Ushikubo, T.; Tenner, T.J.; Hiyagon, H.; Kita, N.T.
A long duration of the ¹⁶O-rich reservoir in the solar nebula, as recorded in fine-grained refractory inclusions from the least metamorphosed carbonaceous chondrites
Geochimica et Cosmochimica Acta, 2017
201, 103, 122
[Reviewed]
Lead, Corresponding

Williford, K.H.; Ushikubo, T.; Lepot, K.; Kitajima, K.; Hallmann, C.; Spicuzza, M.J.; Kozdon, R.; Eigenbrode, J.L.; Summons, R.E.; Valley, J.W.
Carbon and sulfur isotopic signatures of ancient life and environment at the microbial scale: Neoarchean shales and carbonates
Geobiology, 2016
14, 2, 105, 128
[Reviewed]

Valley, J.W.; Reinhard, D.A.; Cavosie, A.J.; Ushikubo, T.; Lawrence, D.F.; Larson, D.J.; Kelly, T.F.; Snoeyenbos, D.R.; Strickland, A.
Presidential Address. Nano-and micro-geochronology in Hadean and Archean zircons by atom-probe tomography and SIMS: New tools for old minerals
American Mineralogist, 2015
100, 7, 1355, 1377
[Reviewed]

Tenner, T.J.; Nakashima, D.; Ushikubo, T.; Kita, N.T.; Weisberg, M.K.
Oxygen isotope ratios of FeO-poor chondrules in CR3 chondrites: Influence of dust enrichment and H2O during chondrule formation
Geochimica et Cosmochimica Acta, 2015
148, 228, 250
[Reviewed]

Nakashima, D.; Ushikubo, T.; Kita, N.T.; Weisberg, M.K.; Zolensky, M.E.; Ebel, D.S.
Late formation of a comet Wild 2 crystalline silicate particle, Pyxie, inferred from Al-Mg chronology of plagioclase
Earth and Planetary Science Letters, 2015
410, 54, 61
[Reviewed]

Joswiak, D.J.; Nakashima, D.; Brownlee, D.E.; Matrajt, G.; Ushikubo, T.; Kita, N.T.; Messenger, S.; Ito, M.
Terminal particle from Stardust track 130: Probable Al-rich chondrule fragment from comet Wild 2
Geochimica et Cosmochimica Acta, 2014
144, 277, 298
[Reviewed]

Bonamici, C.E.; Kozdon, R.; Ushikubo, T.; Valley, J.W.
Intragrain oxygen isotope zoning in titanite by SIMS: Cooling rates and fluid infiltration along the Carthage-Colton Mylonite Zone, Adirondack Mountains, NY, USA
Journal of Metamorphic Geology, 2014
32, 1, 71, 92
[Reviewed]

Valley, J.W.; Cavosie, A.J.; Ushikubo, T.; Reinhard, D.A.; Lawrence, D.F.; Larson, D.J.; Clifton, P.H.; Kelly, T.F.; Wilde, S.A.; Moser, D.E.; Spicuzza, M.J.
Hadean age for a post-magma-ocean zircon confirmed by atom-probe tomography
Nature Geoscience, 2014
7, 3, 219, 223
[Reviewed]

Xing, G.-F.; Wang, X.-L.; Wan, Y.; Chen, Z.-H.; Jiang, Y.; Kitajima, K.; Ushikubo, T.; Gopon, P.
Diversity in early crustal evolution: 4100 Ma zircons in the Cathaysia Block of southern China
Scientific Reports, 2014
4
[Reviewed]

Ushikubo, T.; Williford, K.H.; Farquhar, J.; Johnston, D.T.; Van Kranendonk, M.J.; Valley, J.W.
Development of in situ sulfur four-isotope analysis with multiple Faraday cup detectors by SIMS and application to pyrite grains in a Paleoproterozoic glaciogenic sandstone
Chemical Geology, 2014
383, 86, 99
[Reviewed]

Valley, J.W.; Spicuzza, M.J.; Ushikubo, T.
Correlated δ¹⁸O and [Ti] in lunar zircons: A terrestrial perspective for magma temperatures and water content on the Moon
Contributions to Mineralogy and Petrology, 2014
167, 1, 1, 15
[Reviewed]

Lepot, K.; Williford, K.H.; Ushikubo, T.; Sugitani, K.; Mimura, K.; Spicuzza, M.J.; Valley, J.W.
Texture-specific isotopic compositions in 3.4Gyr old organic matter support selective preservation in cell-like structures
Geochimica et Cosmochimica Acta, 2013
112, 66, 86
[Reviewed]

Harwood, J.; Aplin, A.C.; Fialips, C.I.; Iliffe, J.E.; Kozdon, R.; Ushikubo, T.; Valley, J.W.
Quartz cementation history of sandstones revealed by high-resolution sims oxygen isotope analysis
Journal of Sedimentary Research, 2013
83, 7, 522, 530
[Reviewed]

Strickland, B.A.; Wooden, J.L.; Mattinson, C.G.; Ushikubo, T.; Miller, D.M.; Valley, J.W.
Proterozoic evolution of the Mojave crustal province as preserved in the Ivanpah Mountains, southeastern California
Precambrian Research, 2013
224, 222, 241
[Reviewed]

Williford, K.H.; Ushikubo, T.; Schopf, J.W.; Lepot, K.; Kitajima, K.; Valley, J.W.
Preservation and detection of microstructural and taxonomic correlations in the carbon isotopic compositions of individual Precambrian microfossils
Geochimica et Cosmochimica Acta, 2013
104, 165, 182
[Reviewed]

Grimes, C.B.; Ushikubo, T.; Kozdon, R.; Valley, J.W.
Perspectives on the origin of plagiogranite in ophiolites from oxygen isotopes in zircon
Lithos, 2013
179, 48, 66
[Reviewed]

Nakashima, D.; Kita, N.T.; Ushikubo, T.; Noguchi, T.; Nakamura, T.; Valley, J.W.
Oxygen three-isotope ratios of silicate particles returned from asteroid Itokawa by the Hayabusa spacecraft: A strong link with equilibrated LL chondrites
Earth and Planetary Science Letters, 2013
379, 127, 136
[Reviewed]

Tenner, T.J.; Ushikubo, T.; Kurahashi, E.; Kita, N.T.; Nagahara, H.
Oxygen isotope systematics of chondrule phenocrysts from the CO3.0 chondrite Yamato 81020: Evidence for two distinct oxygen isotope reservoirs
Geochimica et Cosmochimica Acta, 2013
102, 226, 245
[Reviewed]

Matta, M.E.; Orland, I.J.; Ushikubo, T.; Helser, T.E.; Black, B.A.; Valley, J.W.
Otolith oxygen isotopes measured by high-precision secondary ion mass spectrometry reflect life history of a yellowfin sole (Limanda aspera)
Rapid Communications in Mass Spectrometry, 2013
27, 6, 691, 699
[Reviewed]

Bullock, E.S.; Knight, K.B.; Richter, F.M.; Kita, N.T.; Ushikubo, T.; MacPherson, G.J.; Davis, A.M.; Mendybaev, R.A.
Mg and Si isotopic fractionation patterns in types B1 and B2 CAIs: Implications for formation under different nebular conditions
Meteoritics and Planetary Science, 2013
48, 8, 1440, 1458
[Reviewed]

Kita, N.T.; Welten, K.C.; Valley, J.W.; Spicuzza, M.J.; Nakashima, D.; Tenner, T.J.; Ushikubo, T.; MacPherson, G.J.; Welzenbach, L.; Heck, P.R.; Davis, A.M.; Meier, M.M.M.; Wieler, R.; Caffee, M.W.; Laubenstein, M.; Nishiizumi, K.
Fall, classification, and exposure history of the Mifflin L5 chondrite
Meteoritics and Planetary Science, 2013
48, 4, 641, 655
[Reviewed]

Ushikubo, T.; Nakashima, D.; Kimura, M.; Tenner, T.J.; Kita, N.T.
Contemporaneous formation of chondrules in distinct oxygen isotope reservoirs
Geochimica et Cosmochimica Acta, 2013
109, 280, 295
[Reviewed]

Kita, N.T.; Yin, Q.-Z.; Macpherson, G.J.; Ushikubo, T.; Jacobsen, B.; Nagashima, K.; Kurahashi, E.; Krot, A.N.; Jacobsen, S.B.
²⁶Al-²⁶Mg isotope systematics of the first solids in the early solar system
Meteoritics and Planetary Science, 2013
48, 8, 1383, 1400
[Reviewed]

MacPherson, G.J.; Kita, N.T.; Ushikubo, T.; Bullock, E.S.; Davis, A.M.
Well-resolved variations in the formation ages for Ca-Al-rich inclusions in the early Solar System
Earth and Planetary Science Letters, 2012
331-332, 43, 54
[Reviewed]

Orland, I.J.; Bar-Matthews, M.; Ayalon, A.; Matthews, A.; Kozdon, R.; Ushikubo, T.; Valley, J.W.
Seasonal resolution of Eastern Mediterranean climate change since 34ka from a Soreq Cave speleothem
Geochimica et Cosmochimica Acta, 2012
89, 240, 255
[Reviewed]

Kitajima, K.; Ushikubo, T.; Kita, N.T.; Maruyama, S.; Valley, J.W.
Relative retention of trace element and oxygen isotope ratios in zircon from Archean rhyolite, Panorama Formation, North Pole Dome, Pilbara Craton, Western Australia
Chemical Geology, 2012
332-333, 102, 115
[Reviewed]

Ushikubo, T.; Kimura, M.; Kita, N.T.; Valley, J.W.
Primordial oxygen isotope reservoirs of the solar nebula recorded in chondrules in Acfer 094 carbonaceous chondrite
Geochimica et Cosmochimica Acta, 2012
90, 242, 264
[Reviewed]

Nakashima, D.; Ushikubo, T.; Joswiak, D.J.; Brownlee, D.E.; Matrajt, G.; Weisberg, M.K.; Zolensky, M.E.; Kita, N.T.
Oxygen isotopes in crystalline silicates of comet Wild 2: A comparison of oxygen isotope systematics between wild 2 particles and chondritic materials
Earth and Planetary Science Letters, 2012
357-358, 355, 365
[Reviewed]

Bouvier, A.-S.; Ushikubo, T.; Kita, N.T.; Cavosie, A.J.; Kozdon, R.; Valley, J.W.
Li isotopes and trace elements as a petrogenetic tracer in zircon: Insights from Archean TTGs and sanukitoids
Contributions to Mineralogy and Petrology, 2012
163, 5, 745, 768
[Reviewed]

Kita, N.T.; Ushikubo, T.; Knight, K.B.; Mendybaev, R.A.; Davis, A.M.; Richter, F.M.; Fournelle, J.H.
Internal ²⁶Al- ²⁶Mg isotope systematics of a Type B CAI: Remelting of refractory precursor solids
Geochimica et Cosmochimica Acta, 2012
86, 37, 51
[Reviewed]

Nakashima, D.; Ushikubo, T.; Zolensky, M.E.; Kita, N.T.
High precision oxygen three-isotope analyses of anhydrous chondritic interplanetary dust particles
Meteoritics and Planetary Science, 2012
47, 2, 197, 208
[Reviewed]

Kita, N.T.; Ushikubo, T.
Evolution of protoplanetary disk inferred from ²⁶Al chronology of individual chondrules
Meteoritics and Planetary Science, 2012
47, 7, 1108, 1119
[Reviewed]

Grimes, C.B.; Ushikubo, T.; John, B.E.; Valley, J.W.
Uniformly mantle-like δ¹⁸O in zircons from oceanic plagiogranites and gabbros
Contributions to Mineralogy and Petrology, 2011
161, 1, 13, 33
[Reviewed]

Cavosie, A.J.; Valley, J.W.; Kita, N.T.; Spicuzza, M.J.; Ushikubo, T.; Wilde, S.A.
The origin of high δ¹⁸O zircons: Marbles, megacrysts, and metamorphism
Contributions to Mineralogy and Petrology, 2011
162, 5, 961, 974
[Reviewed]

Heck, P.R.; Huberty, J.M.; Kita, N.T.; Ushikubo, T.; Kozdon, R.; Valley, J.W.
SIMS analyses of silicon and oxygen isotope ratios for quartz from Archean and Paleoproterozoic banded iron formations
Geochimica et Cosmochimica Acta, 2011
75, 20, 5879, 5891
[Reviewed]

Weisberg, M.K.; Ebel, D.S.; Connolly, H.C.; Kita, N.T.; Ushikubo, T.
Petrology and oxygen isotope compositions of chondrules in E3 chondrites
Geochimica et Cosmochimica Acta, 2011
75, 21, 6556, 6569
[Reviewed]

Rudraswami, N.G.; Ushikubo, T.; Nakashima, D.; Kita, N.T.
Oxygen isotope systematics of chondrules in the Allende CV3 chondrite: High precision ion microprobe studies
Geochimica et Cosmochimica Acta, 2011
75, 23, 7596, 7611
[Reviewed]

Nakashima, D.; Ushikubo, T.; Gowda, R.N.; Kita, N.T.; Valley, J.W.; Nagao, K.
Ion microprobe analyses of oxygen three-isotope ratios of chondrules from the Sayh al Uhaymir 290 CH chondrite using a multiple-hole disk
Meteoritics and Planetary Science, 2011
46, 6, 857, 874
[Reviewed]

Bonamici, C.E.; Kozdon, R.; Ushikubo, T.; Valley, J.W.
High-resolution P-T-t paths from δ¹⁸O zoning in titanite: A snapshot of late-orogenic collapse in the Grenville of New York
Geology, 2011
39, 10, 959, 962
[Reviewed]

Hiyagon, H.; Yamakawa, A.; Ushikubo, T.; Lin, Y.; Kimura, M.
Fractionation of rare earth elements in refractory inclusions from the Ningqiang meteorite: Origin of positive anomalies in Ce, Eu, and Yb
Geochimica et Cosmochimica Acta, 2011
75, 12, 3358, 3384
[Reviewed]

Ferry, J.M.; Ushikubo, T.; Valley, A.W.
Formation of forsterite by silicification of dolomite during contact metamorphism
Journal of Petrology, 2011
52, 9, 1619, 1640
[Reviewed]

Schmitz, B.; Heck, P.R.; Alwmark, C.; Kita, N.T.; Meier, M.M.M.; Peucker-Ehrenbrink, B.; Ushikubo, T.; Valley, J.W.
Determining the impactor of the Ordovician Lockne crater: Oxygen and neon isotopes in chromite versus sedimentary PGE signatures
Earth and Planetary Science Letters, 2011
306, 3-4, 149, 155
[Reviewed]

Williford, K.H.; Van Kranendonk, M.J.; Ushikubo, T.; Kozdon, R.; Valley, J.W.
Constraining atmospheric oxygen and seawater sulfate concentrations during Paleoproterozoic glaciation: In situ sulfur three-isotope microanalysis of pyrite from the Turee Creek Group, Western Australia
Geochimica et Cosmochimica Acta, 2011
75, 19, 5686, 5705
[Reviewed]

Noguchi, T.; Nakamura, T.; Ushikubo, T.; Kita, N.T.; Valley, J.W.; Yamanaka, R.; Kimoto, Y.; Kitazawa, Y.
A chondrule-like object captured by space-exposed aerogel on the international space station
Earth and Planetary Science Letters, 2011
309, 3-4, 198, 206
[Reviewed]

MacPherson, G.J.; Bullock, E.S.; Janney, P.E.; Kita, N.T.; Ushikubo, T.; Davis, A.M.; Wadhwa, M.; Krot, A.N.
Early solar nebula condensates with canonical, not supracanonical, initial ²⁶Al/²⁷Al ratios
Astrophysical Journal Letters, 2010
711, 2 PART 2
[Reviewed]

Ferry, J.M.; Ushikubo, T.; Kita, N.T.; Valley, J.W.
Assessment of grain-scale homogeneity and equilibration of carbon and oxygen isotope compositions of minerals in carbonate-bearing metamorphic rocks by ion microprobe
Geochimica et Cosmochimica Acta, 2010
74, 22, 6517, 6540
[Reviewed]

Heck, P.R.; Ushikubo, T.; Schmitz, B.; Kita, N.T.; Spicuzza, M.J.; Valley, J.W.
A single asteroidal source for extraterrestrial Ordovician chromite grains from Sweden and China: High-precision oxygen three-isotope SIMS analysis
Geochimica et Cosmochimica Acta, 2010
74, 2, 497, 509
[Reviewed]

Liu, Y.; Taylor, L.A.; Sarbadhikari, A.B.; Valley, J.W.; Ushikubo, T.; Spicuzza, M.J.; Kita, N.; Ketcham, R.A.; Carlson, W.; Shatsky, V.; Sobolev, N.V.
Metasomatic origin of diamonds in the world's largest diamondiferous eclogite
Lithos, 2009
112, 1014, 1024
[Reviewed]

Kozdon, R.; Ushikubo, T.; Kita, N.T.; Spicuzza, M.; Valley, J.W.
Intratest oxygen isotope variability in the planktonic foraminifer N. pachyderma: Real vs. apparent vital effects by ion microprobe
Chemical Geology, 2009
258, 3-4, 327, 337
[Reviewed]

Kita, N.T.; Ushikubo, T.; Fu, B.; Valley, J.W.
High precision SIMS oxygen isotope analysis and the effect of sample topography
Chemical Geology, 2009
264, 1-4, 43, 57
[Reviewed]

Hsu, W.; Zhang, A.; Bartoschewitz, R.; Guan, Y.; Ushikubo, T.; Krähenbühl, U.; Niedergesaess, R.; Pepelnik, R.; Reus, U.; Kurtz, T.; Kurtz, P.
Petrography, mineralogy, and geochemistry of lunar meteorite Sayh al Uhaymir 300
Meteoritics and Planetary Science, 2008
43, 8, 1363, 1381
[Reviewed]

Ushikubo, T.; Kita, N.T.; Cavosie, A.J.; Wilde, S.A.; Rudnick, R.L.; Valley, J.W.
Lithium in Jack Hills zircons: Evidence for extensive weathering of Earth's earliest crust
Earth and Planetary Science Letters, 2008
272, 3-4, 666, 676
[Reviewed]

Weidel, B.C.; Ushikubo, T.; Carpenter, S.R.; Kita, N.T.; Cole, J.J.; Kitchell, J.F.; Pace, M.L.; Valley, J.W.
Diary of a bluegill (Lepomis macrochirus): Daily δ¹³C and δ¹⁸O records in otoliths by ion microprobe
Canadian Journal of Fisheries and Aquatic Sciences, 2008
29, 12, 1641, 1645
[Reviewed]

Nakamura, T.; Noguchi, T.; Tsuchiyama, A.; Ushikubo, T.; Kita, N.T.; Valley, J.W.; Zolensky, M.E.; Kakazu, Y.; Sakamoto, K.; Mashio, E.; Uesugi, K.; Nakano, T.
Chondrulelike objects in short-period comet 81P/wild 2
Science, 2008
321, 5896, 1664, 1667
[Reviewed]

Page, F.Z.; Ushikubo, T.; Kita, N.T.; Riciputi, L.R.; Valley, J.W.
High-precision oxygen isotope analysis of picogram samples reveals 2 μm gradients and slow diffusion in zircon
American Mineralogist, 2007
92, 10, 1772, 1775
[Reviewed]

Ushikubo, T.; Hiyagon, H.; Sugiura, N.
A FUN-like hibonite inclusion with a large ²⁶Mg-excess
Earth and Planetary Science Letters, 2007
254, 1-2, 115, 126
[Reviewed]

Ushikubo, T.; Guan, Y.; Hiyagon, H.; Sugiura, N.; Leshin, L.A.
³⁶Cl, ²⁶Al, and O isotopes in an Allende type B2 CAI: Implications for multiple secondary alteration events in the early solar system
Meteoritics and Planetary Science, 2007
42, 7-8, 1267, 1279
[Reviewed]

Hsu, W.; Guan, Y.; Leshin, L.A.; Ushikubo, T.; Wasserburg, G.J.
A late episode of irradiation in the early solar system: Evidence from extinct³⁶Cl and ²⁶Al in meteorites
Astrophysical Journal, 2006
640, 1 I, 525, 529
[Reviewed]

Yada, T.; Nakamura, T.; Noguchi, T.; Matsumoto, N.; Kusakabe, M.; Hiyagon, H.; Ushikubo, T.; Sugiura, N.; Kojima, H.; Takaoka, N.
Oxygen isotopic and chemical compositions of cosmic spherules collected from the Antarctic ice sheet: Implications for their precursor materials
Geochimica et Cosmochimica Acta, 2005
69, 24, 5789, 5804
[Reviewed]

Sugiura, N.; Mizuno, T.; Ushikubo, T.; Hiyagon, H.
Si and Mg isotope fractionations in melilite in coarse-grained CAIs measured by SIMS
Geochemical Journal, 2004
38, 5, 405, 415
[Reviewed]

牛久保孝行; 羽根由里奈; 木村伸吾
耳石の局所酸素同位体比分析で探るクロマグロ産卵海域の動態　　　　　　　　　　　　　　　
Isotope News（日本アイソトープ協会広報誌）, Aug. 2024
2024, 8, 20, 24
[Invited]
Lead, Corresponding

Takayuki Ushikubo
An acompanying story of the study on Lithium in Zircon　　　　　　　　　　　　　　　
Journal of the Mass Spectrometry Society of Japan, Apr. 2022
70, 2, 135, 136
[Invited]

牛久保 孝行
微なるかな微なるかな、地球初期に至る ー微小領域分析で挑む大陸形成の始まりー
Blue Earth 海と地球の情報誌, Mar. 2017
29, 148, 28, 31

牛久保 孝行
Precise Isotope Analysis : Development of Analytical Protocols and Applications of High Precision in situ Isotope Analyses by SIMS
ぶんせき（日本分析化学会誌）, Oct. 2016
2016, 10, 390, 396
[Reviewed], [Invited]

牛久保 孝行
エポックメイキングな隕石たち（その7）：Acfer 094隕石～初期太陽系微粒子の宝庫～
遊星人（日本惑星科学会誌）, Mar. 2016
25, 1, 8, 12
[Reviewed], [Invited]

牛久保 孝行
高精度・微小領域酸素同位体局所分析の取り組み　　　　　　　　　　　　　　　
遊星人（日本惑星科学会誌）, Dec. 2010
19, 4, 287, 294
[Reviewed]

NAKAMURA Tomoki; NOGUCHI Takaaki; TSUCHIYAMA Akira; USHIKUBO Takayuki; KITA Noriko T.; VALLEY John W.; ZOLENSKY Michael E.; KAKAZU Yuki; SAKAMOTO Kanako; MASHIO Etsuko; UESUGI Kentaro; NAKANO Tsukasa
Chondrules in short-period comet 81P/Wild 2 recovered by the Stardust mission
Chikyukagaku, 2009
43, 4, 143, 153

Tenner T. J; Ushikubo T; Nakashima D; Schrader D. L; Weisberg M. K; Kimura M; Kita N. T, Joint work, Section 8: Oxygen Isotope Characteristics of Chondrules from Recent Studies by Secondary Ion Mass Spectrometry
Chondrules: Records of Protoplanetary Disk Processes　　　　　　　　　　　　　　　
Cambridge University Press, Jul. 2018

牛久保 孝行
酸素同位体比から推定されるコンドルール形成環境　　　　　　　　　　　　　　　
神戸大学惑星科学研究センター CPSセミナー, 06 Oct. 2025, [Invited]

牛久保 孝行; 福田 航平; 中嶋 大輔; 木多 紀子
コンドルールの同位体比データから導かれる原始太陽系円盤の進化過程への制約　　　　　　　　　　　　　　　
JpGU 2025, 26 May 2025

Ushikubo T.; Shimizu K.
Systematic analyses of Volatile abundances, Hydrogen and Sulfur isotope ratios of melt inclusions　　　　　　　　　　　　　　　
Goldschmidt Conference 2024, 20 Aug. 2024

Ushikubo T.; Tomioka N.; Yamaguchi A.
Isotopic and mineralogical study of carbonates in Aguas Zarcas　　　　　　　　　　　　　　　
Annual Meeting of the Meteoritical Society, 01 Aug. 2024

牛久保 孝行
無水鉱物の同位体比情報から氷や流体の特徴を読み解く　　　　　　　　　　　　　　　
JpGU 2024, 26 May 2024, [Invited]

牛久保 孝行
On-siteと帰還試料の酸素同位体比分析の重要性　　　　　　　　　　　　　　　
Comet Interceptor + 次世代小天体SR合同サイエンス会合, 13 Sep. 2023

Ushikubo T; Tani K
Oxygen and silicon isotope systematics of zircons from Izu-Bonin-Mariana arc and the Izu collision zone, a modern analogue of the early evolved crust formation　　　　　　　　　　　　　　　
6th International Archean Symposium, 25 Jul. 2023

牛久保 孝行; 山口 亮; Michael K. Weisberg; Denton S. Ebel; 木村 眞
CM, CRコンドライトとTagish Lake隕石の炭酸塩の炭素、酸素同位体比組成　　　　　　　　　　　　　　　
JpGU 2023, 26 May 2023

Ushikubo T; Yamaguchi A; Weisberg M. K; Kimura M; Ebel D. S
Evidence for high d13C and D17O fluid in small bodies accreted in a cold and distant region from the Sun　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference 2023, 15 Mar. 2023

牛久保 孝行
無水鉱物に記録された隕石母天体集積領域の氷の酸素同位体比情報を読み解く　　　　　　　　　　　　　　　
新学術領域「星・惑星形成」2022年度大研究会, 20 Feb. 2023

牛久保 孝行; 清水 健二; 野崎 達生; 鳥本 淳司; 長瀬 敏郎; 久保田 勇祐; 中川 麻悠子; 上野 雄一郎
SIMSを用いた硫化鉱物の局所硫黄2～4同位体比分析高精度化への取り組み　　　　　　　　　　　　　　　
2022年度日本地球化学会, 07 Sep. 2022

牛久保 孝行
太陽系始原ダストの物質科学　　　　　　　　　　　　　　　
始原天体ワークショップ, 15 Mar. 2022, [Invited]

Ushikubo T; Yamaguchi A; Weisberg M. K; Kimura M; Ebel D. S
Consistently high d13C carbonates in CR chondrites: Implication for accreted ice in a cold and distant region from the Sun　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference 2022, 07 Mar. 2022

牛久保 孝行
CR vs. CM: 炭素質コンドライトの炭酸塩とコンドルールの同位体組成の比較　　　　　　　　　　　　　　　
水惑星全体会議, 02 Mar. 2022

Takayuki Ushikubo; Makoto Kimura
Oxygen isotopic systematics of chondrules in Tagish Lake (C2) and implications of volatiles in the protoplanetary disk　　　　　　　　　　　　　　　
JpGU 2021, 05 Jun. 2021

牛久保 孝行
隕石試料の酸素・炭素同位体比研究の進捗報告
水惑星学全体会議, 09 Mar. 2021

USHIKUBO T; KIMURA M
Oxygen isotope systematics of chondrules and olivine fragments from Tagish Lake C2 chondrite　　　　　　　　　　　　　　　
The 11th Symposium on Polar Science, 03 Dec. 2020

牛久保 孝行
コンドルールから原始惑星系円盤での固体粒子の移動を探る　　　　　　　　　　　　　　　
新学術領域 星惑星形成 大研究会, 01 Oct. 2020

T. Ushikubo; K. Shimizu; T. Nozaki; T. Nagase
Recent progress of in situ sulfur 2 and 4 isotope measurements at Kochi Institute, JAMSTEC　　　　　　　　　　　　　　　
JpGU 2020, 14 Jul. 2020

牛久保 孝行
無水鉱物の酸素同位体比から水の存在を探る　　　　　　　　　　　　　　　
水惑星学全体会議, 12 Nov. 2019

USHIKUBO T; SHIMIZU K
Development for in-situ volatile element abundances, and hydrogen and sulfur 2-isotope analyses of silicate glasses by SIMS　　　　　　　　　　　　　　　
82nd Annual Meeting for the Meteoritical Society, 09 Jul. 2019

Takayuki Ushikubo; Makoto Kimura
Characteristics of oxygen isotope ratios of chondrules and isolated olivine grains from Tagish Lake C2 chondrite　　　　　　　　　　　　　　　
JpGU 2019, 27 May 2019

USHIKUBO T; KIMURA M
Oxygen isotope systematics of chondrules and isolated olivine grains from the Tagish Lake C2 chondrite　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference L, 20 Mar. 2019

USHIKUBO T; FUJIYA W
In situ oxygen three-isotope analysis of carbonates with 15um and 3um beam: Preliminary results　　　　　　　　　　　　　　　
Hayabusa 2018, 06 Dec. 2018

USHIKUBO Takayuki
Los condrulos no vuelan: SIMS oxygen isotope studies of chondrules　　　　　　　　　　　　　　　
CPS Seminar, 28 Jun. 2018, [Invited]

Takayuki Ushikubo, Kenichiro Tani, R. Bastian Georg
Characteristics of O and Si isotope ratios of zircons of silicic rocks from the Izu-Bonin-Mariana (IBM) arc and the Izu collision zone (ICZ)　　　　　　　　　　　　　　　
JpGU2018, 21 May 2018

Ushikubo T; Tani K; Georg R. B
Oxygen and silicon isotope ratios of zircons of silicic rocks from the Izu-Bonin-Mariana (IBM) intra-oceanic arc and arc collision zone　　　　　　　　　　　　　　　
GSA 2017, 23 Oct. 2017

牛久保 孝行; 清水 健二; 飯塚 毅; 上原 啓幹; 小宮 剛; 谷 健一郎; 上野 雄一郎
局所同位体比分析で地球地殻形成史を探る　　　　　　　　　　　　　　　
日本地質学会, 18 Sep. 2017, [Invited]

牛久保 孝行; 清水 健二
地球内部・表層環境における硫黄同位体比変動の研究に向けた局所硫黄2同位体比分析手法開発　　　　　　　　　　　　　　　
JpGU2017, 24 May 2017, [Invited]

Ushikubo T
Development of in situ Oxygen, Silicon, and Sulfur isotope analysis techniques by SIMS at Kochi Institute, JAMSTEC.　　　　　　　　　　　　　　　
4th International Geoscience Symposium “Precambrian World 2017, 03 Mar. 2017

Ushikubo T; Tenner T. J; Hiyagon H; Kita N. T
Evidence for a long duration of the 16O-rich reservoir in the Solar Nebula.　　　　　　　　　　　　　　　
79th Annual Meteoritical Society Meeting, Aug. 2016

Ushikubo T; Shimizu K; Ueno Y
Hydrogen isotope analyses of forearc volcanic glasses from IODP Exp. 352 using IMS 1280-HR　　　　　　　　　　　　　　　
Goldschmidt 2016, 28 Jun. 2016

Ushikubo T; Nakashima D; Tenner T. J; Defouilloy C; Kita N. T
Redox and oxygen isotopic change in the solar nebula recorded in chondrules　　　　　　　　　　　　　　　
Workshop on Experimental Cosmochemistry 2016, 26 Jun. 2016

Ushikubo T; Iizuka T; Spicuzza M. J; Valley J. W
Evidence from the Acasta zircons for consistent occurrence of magmas with moderately elevated d18O throughout the Eoarchean　　　　　　　　　　　　　　　
JpGU 2016, 25 May 2016

Ushikubo T; Iizuka T; Spicuzza M. J; Valley J. W
Consistent occurrence of moderately elevated 18O magmas in Acasta gneiss complex from 4.0 to 3.5 Ga　　　　　　　　　　　　　　　
Goldschmidt 2015, 18 Aug. 2015

牛久保 孝行; 伊藤 元雄; 富岡 尚敬; 清水 健二; 石川 剛志
高知コア研究所におけるSIMSを用いた高精度局所同位体比分析法開発の取り組みと、今後の研究の展望　　　　　　　　　　　　　　　
JpGU 2015, 26 May 2015

牛久保 孝行; Valley J. W
二次イオン質量分析計（SIMS）を用いたジルコンのリチウム濃度・同位体比組成の探求　　　　　　　　　　　　　　　
日本地質学会, 17 Sep. 2012, [Invited]

牛久保 孝行; 木村 眞; Tenner T. J; 中嶋 大輔; Valley J. W; 木多 紀子
コンドルール形成環境の酸素同位体比の特徴　　　　　　　　　　　　　　　
日本地球化学会, 12 Sep. 2012

Ushikubo T; Tenner T. J; Hiyagon H; Kita N. T
Lifetime of 16O-rich Oxygen Isotope Reservoir in the Solar Nebula　　　　　　　　　　　　　　　
Workshop of the first solids in the solar system, 09 Nov. 2011

USHIKUBO Takayuki
Oxygen isotope systematics of chondrules: An example of combined oxygen-isotope analyses using 3m and 15m primary beams　　　　　　　　　　　　　　　
Biennial GeoSIMS Workshop 6, 03 Nov. 2011

Ushikubo T; Kimura M; Kita N. T; Valley J. W
Primordial Oxygen Isotope Reservoirs of the Solar Nebula Recorded in Chondrules from Acfer 094 Carbonaceous Chondrite　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XLII, 08 Mar. 2011

Ushikubo T; Kita N. T; Valley J. W
Recent progress of small spot oxygen isotope analysis at WiscSIMS　　　　　　　　　　　　　　　
Goldschmidt 2010, 14 Jun. 2010

Ushikubo T; Kimura M; Nakashima D; Kita N. T
A Combined Study of the Al-Mg Systematics and O Isotope Ratios of Chondrules from the Primitive Carbonaceous Chondrite Acfer 094　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XLI, 05 Mar. 2010

Ushikubo T; Kimura M; Kita N. T; Valley J. W
Oxygen isotopic compositions of phenocrysts in chondrules from the primitive carbonaceous chondrite Acfer 094　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XL, 25 Mar. 2009

Ushikubo T; Kita N. T; Cavosie A. J; Wilde S. A; Rudnick R. L; Valley J. W
Lithium in Jack Hills Zircon: Evidence for extreme weathering of Earth’s Crust at 4300 Ma　　　　　　　　　　　　　　　
Goldschmidt 2008, 14 Jul. 2008

Ushikubo T; Kita N. T; Cavosie A. J; Wilde S. A; Rudnick R. L; Valley J. W
Li in >4.0 Ga Jack Hills zircon　　　　　　　　　　　　　　　
5th Biannual GeoSIMS Workshop, 14 Jun. 2008

Ushikubo T; Page F. Z; Kita N. T; Riciputi L. R; Valley J. W
Sub-um size high precision analysis of d18O in zircon by SIMS　　　　　　　　　　　　　　　
Goldschmidt 2007, Aug. 2007

USHIKUBO T; Kita N. T; Valley J. W; Weidel B; Kitchell J. F; Carpenter S. R; Cole J. J; Pace M. L
In situ C and O isotopic measurements of a fish otolith　　　　　　　　　　　　　　　
SIMS in Space Sciences: The Zinner Impact, 03 Feb. 2007

Ushikubo T; Guan Y; Hiyagon H; Sugiura N; Leshin L. A
36Cl, 26Al, and oxygen isotopes in an Allende CAI: Implications for secondary alteration in the early Solar System　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XXXVII, 16 Mar. 2006

Ushikubo T; Guan Y; Leshin L. A
10Be-10B systematics of hibonite-bearing inclusions from Murchison (CM2) and Kainsaz (CO3)　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XXXVII, 16 Mar. 2006

Ushikubo T; Guan Y; Leshin L. A
36Cl and 26Al in the Allende carbonaceous chondrite: Implications for secondary alteration in the early Solar System　　　　　　　　　　　　　　　
4th Biennial Goechemical SIMS Workshop, 10 Dec. 2005

Ushikubo T; Hiyagon H; Sugiura N
Oxygen, Ca, and Ti iostopic compositions of hibonite-bearing inclusions　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XXXVI, 17 Mar. 2005

Ushikubo T; Hiyagon H; Hashimoto A; Kimura M
Oxygen isotopic composition and REE abundances of a Zr-rich-oxide-bearing inclusion from Murchison　　　　　　　　　　　　　　　
Annual Meeting of the Meteoritical Society, 05 Aug. 2004

Ushikubo T; Hiyagon H; Kimra M; Hashimoto A
An ultra-refractory nodule in an Allende fine-grained inclusion: Isotopic studies using SIMS　　　　　　　　　　　　　　　
Goldschmidt 2003, 08 Sep. 2003

Ushikubo T; Hirain K; Hiyagon H
Mg isotopic compositions of W-L and accretionary rims of CAIs　　　　　　　　　　　　　　　
Goldschmidt 2002, 20 Aug. 2002

Ushikubo T; Hirai K; Hiyagon H
Mg isotopic compositions of Wark-Lovering and accretionary rims of CAIs　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XXXIII, 14 Mar. 2002

Ushikubo T; Hiyagon H; Sugiura N
A FUN-like hibonite inclusion in Kainsaz CO3 chondrite with large 41K and 26Mg excesses at the level of normal CAIs　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XXXI, 15 Mar. 2000

Ushikubo T; Hiyagon H; Sugiura N; Ulyanov A. A
Combined ion microprobe studies of O and Mg isotopes in an Efremovka CAI　　　　　　　　　　　　　　　
Lunar and Planetary Science Conference XXX, 16 Mar. 1999

Ushikubo T; Hiyagon H; Sugiura N; Ulyanov A. A
Mg isotopic anomaly of two types of anorthite in CAIs　　　　　　　　　　　　　　　
Antarctic meteorite XXIV, 16 Mar. 1999

Ushikubo T; Hiyagon H; Sugiura N
A preliminary experiment for K isotope analysis of CAI　　　　　　　　　　　　　　　
Antarctic meteorite XXIII, 12 Jun. 1998