Dr. Tomohiro Usui
Astromaterial Research Office
Johnson Space Center/ NASA
Mail code KR, 2101 Nasa Pwky,
Houston, TX 77058-3969
Tomohiro has a BS in petrology; and both masters and doctorate degrees in petrology and geochemistry. He is a geo- & planetary scientist, currently working at Johnson Space Center (NASA), to understand the formation of asteroids and planets, and NASA’s ongoing asteroid exploration mission (Dawn mission).
Tomohiro’s research includes focuses on the petrology and geochemistry of terrestrial and extraterrestrial rocks. During his PhD at ISEI, he mainly studied eclogite xenoliths from the Colorado Plateau as a proxy of the subducted oceanic crust in order to understand material recycling through subduction zones. Now at UTK, he is studying the petrology and geochemistry of Martian meteorites and rocks analyzed by the Mars Exploration Rover Spirit.
His publications include:
- T. Usui, M. Sanborn, M. Wadhwa and H. Y. McSween, Jr. (in press). Petrology and trace element geochemistry of Robert Massif 04261 and 04262 meteorites, the first examples of geochemically enriched lherzolitic shergottites. Geochimica et Cosmochimica Acta.
- T. Usui and H. Y. McSween, Jr., D. W. Mittlefehldt and T. H. Prettyman (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.
- T. Usui, H. Y. McSween, Jr., B. C. Clark III. (2008b). Petrogenesis of high-phosphorous Wishstone-class rocks in Gusev crater, Mars. Journal of Geophysical Research–Planets. 113, E12S44, doi:10.1029/2008JE003225.
- T. Usui, H. Y. McSween, Jr., C. Floss. (2008a). Petrogenesis of olivine-phyric shergottite Yamato-980459, revisited. Geochimica et Cosmochimica Acta 72, 1711–1730.
- T. Usui and H. Y. McSween, Jr. (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.
- T. Usui, K. Kobayashi, E. Nakamura and H. Helmstaedt (2007). Trace element fractionation in deep subduction zones inferred from a lawsonite-eclogite xenolith from the Colorado Plateau. Chemical Geology 239, 336–351.
- T. Kuritani, T. Usui, T. Yokoyama and E. Nakamura. (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.
- T. Usui, E. Nakamura and H. Helmstaedt (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.
- T. Usui, E. Nakamura, K. Kobayashi, S. Maruyama and H. Helmstaedt (2003). Fate of the subducted Farallon plate inferred from eclogite xenoliths in the Colorado Plateau. Geology 30, 589–592.
- T. Usui, K. Kobayashi and E. Nakamura (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.
Dr. Usui's personal webpage
December 27, 2010