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Tomohiro Usui, Visiting Scientist

Justin I. Simon
Area of Research/Engineering

Geochemistry and petrology

Contact Information



Research/Engineering Interests

Formation and differentiation processes of extraterrestrial bodies that include: planetary basalt petrogenesis; asteroidal crust formation; Mars and asteroid exploration; subduction-zone material recycling on Earth

Technical developments that include: in situ ion microprobe analyses; high P-T experiments for mineral/melt elemental partitioning

More information can be found on myLPI Biography page.    

Education / Experience

PhD Institute for Study of the Earth's Interior, Okayama University, Japan 2004

MS Institute for Study of the Earth's Interior, Okayama University, Japan 2001

BS Tokyo Institute of Technology, Japan 1999

Laboratory / Research Group

Peer reviewed articles

Usui, T., Sanborn, M., Wadhwa, M. and McSween, H. Y. (2010). Petrology and trace element geochemistry of Robert Massif 04261 and 04262 meteorites, the first examples of geochemically enriched lherzolitic shergottites. Geoc himica et Cosmochimica Acta. 74, 7283-7306.

Usui, T., McSween, H. Y., Mittlefehldt, D. W. and Prettyman, T. H. (2010). K-Th-Ti systematics and new three-component mixing model and of HED meteorites: Prospective study for interpretation of gamma-ray and neutron spectra for the Dawn mission. Meteoritics & Planetary Science. 45, 1170-1190.

Usui, T., McSween, H. Y., and Clark, B. C. (2008). Petrogenesis of high-phosphorous Wishstone-class rocks in Gusev crater, Mars. Journal of Geophysical Research - Planets. 113, E12S44, doi: 10.1029/2008JE003225.

Usui, T., McSween, H. Y. and Floss, C. (2008). Petrogenesis of olivine-phyric shergottite Yamato-980459, revisited. Geochimica et Cosmochimica Acta 72, 1711-1730.

Usui, T. and McSween, H. Y. (2007). Geochemistry of 4 Vesta based on HED meteorites: Prospective study for interpretation of gamma ray and neutron spectra for the Dawn mission. Meteoritics & Planetary Science 42, 269-283.

Usui, T., Kobayashi, K., Nakamura, E. and Helmstaedt, H. (2007). Trace element fractionation in deep subduction zones inferred from a lawsonite-eclogite xenolith from the Colorado Plateau. Chemical Geology 239, 336-351.

Kuritani, T., Usui, T., Yokoyama, T. and Nakamura, E. (2006). Accurate isotopic and concentration analyses of small amounts of Pb using isotope dilution coupled with the double spike technique. Geostandards and Geoanalytical Research 30, 209-220.

Usui, T., Nakamura, E. and Helmstaedt, H. (2006). Petrology and geochemistry of eclogite xenoliths from the Colorado Plateau: Implications for the evolution of the subducted oceanic crust. Journal of Petrology 47, 929-964.

Usui, T., Nakamura, E., Kobayashi, K., Maruyama, S. and Helmstaedt, H. (2003). Fate of the subducted Farallon plate inferred from eclogite xenoliths in the Colorado Plateau. Geology 30, 589-592. Usui, T., Kobayashi, K. and Nakamura, E. (2002). U-Pb isotope systematics of micro-zircon inclusions: Implications for the age and origin of eclogite xenolith from the Colorado Plateau. Proceedings of the Japan Academy 78, 51-56.

Books, proceedings, and review articles

Usui, T. (in revision) New views of Mars: Reviews of recent Mars explorations and meteorites studies. Chikyu-Kagaku (Geochemical journal published by the Geochemical Society of Japan) (in Japanese)

Usui, T. and Namiki, N. (2011). Report of the 4th Mars Science Laboratory Landing Site Workshop. Planetary Geology News 23 (issue 1), 1-3. (in Japanese).

Usui, T., (2010) Reviews of Scientific Results of Mars Exploration Rovers. In"Mars: Why is Mars Red?" Eds. Miyamoto, H., Hirata, N. Tachibana, S. The University Museum, The University of Tokyo, pp. 175. (in Japanese)

Simon, A. C., King, R. L., Pettke, T. and Usui, T. (2007). Preface: Chemical and physical processes affecting element mobility from the slab to the surface. Chemical Geology 239, 179-181.