Areas of interest:

Micropaleontology, stratigraphy of Neogene sedimentary rocks, paleobiology of Ostracoda (Crustacea)

Current projects:

• (1) Reconstruction of sea-level changes and paleoenvironments of Quaternary shallow marine deposits in Japan based on analyses of fossil ostracodes, sedimentary facies and geochemistry of sediments.
• (2) Study of speciation and migration of shallow marine Ostracoda (Crustacea) in Eastern Asia during the late Neogene using morphometric methods and DNA analysis.
• (3) Sequence stratigraphy and biostratigraphy of lower to middle Miocene deposits in Setouchi Province, southwest Japan.
• (4) Recognition of Holocene Tsunami deposits and their distribution in time and space based on sedimentology and microfossils.

Recent Publications:

• Yamada, K., Irizuki, T. and Tanaka Y., 2002. Cyclic sea-level changes based on fossil ostracode faunas from the Upper Pliocene Sasaoka Formation, Akita Prefecture, northeast Japan. Palaeogeogr., Palaeoclimatol., Palaeoecol., 185: 115-132.
• Yasuhara, M., Irizuki, T., Yoshikawa S., Nanayama, F., 2002. Changes in Holocene ostracode faunas and depositional environments in the Kitan Strait, southwestern Japan. Paleont. Res., 6: 85-99.
• Masuda, F., Irizuki, T., Fujiwara, O., Miyahara, B. and Yoshikawa, S., 2002. A Holocene sea-level curve constructed from a single core at Osaka, Japan (A preliminary note). Mem. Fac. Sci. Kyoto Univ., Ser. Geol. & Mineral., 59: 1-8.
• Irizuki, T., Masuda, F., Miyahara, B., Hirotsu, J., Ueda, S. and Yoshikawa,S., 2001. Vertical changes of Holocene ostracodes in bore hole cores from off Kobe, related to the opening of straits and relative sea-level change inwestern Japan. The Quatern. Res., 40: 105-120.
• Irizuki, T., Ishizaki, K., Takahashi, M. and Usami, M., 1998. Ostracode faunal changes after the mid-Neogene climatic optimum elucidated in the Middle Miocene Kobana Formation, Central Japan. Paleont. Res., 2: 30-47.
• Irizuki, T., 1996. Ontogenetic change in valve characters in three new species of Baffinicythere (Ostracoda, Crustacea) from northern Japan. Jour. Paleont., 70: 450-462.