isozaki

Our research focuses on the fundamental processes of the evolving planet, the Earth, and the evolution history of the unique life on it, in particular, on major mass extinctions (e.g. the Paleozoic-Mesozoic boundary event), rapid radiation of animals (the Cambrian explosion), early evolution of life, subduction-accretion tectonics, and mantle convection of terrestrial planets. Research methods include field mapping, geochemical analyses (major, trace elements and their isotopes), and supercomputer-aided numerical simulation. We explore around the world for fieldwork, such as in Japan, China, Indonesia, Russia, Australia, USA, Canada, UK, Croatia-Slovenia, S. Africa etc.

Yukio Isozaki

Professor (Earth Science)
          Department of Earth Science and Astronomy
          Graduate School of Arts and Sciences
          The University of Tokyo
                              3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
                              Phone: 81-3-5454-6608; FAX: 81-3-5465-8244
                              E-mail: isozaki@ea.c.u-tokyo.ac.jp

Professor at the Department of Earth Science and Astronomy, The University of Tokyo, received Ph. D (1986) from Osaka City University, Japan.     After serving for Yamaguchi University (1981-1993) and Tokyo Institute of Technology (1993-1997), he moved to The University of Tokyo, and promoted to professor in 2000.     His work started in the analysis of on-land exposed ancient accretionary complexes using microfossils (conodont, radiolaria) and geochronological dating.     He clarified that overall pre-Cenozoic shallow crust of Japan is characterized by compressional thin-skinned structure formed through subduction-accretion tectonics.     He summarized ca. 500 million year-long geotectonic evolution of Japan in terms of plate tectonics-controlled orogeny.     His recent interest focuses on mass extinction events in the past, in particular the biggest one in history across the Paleozoic-Mesozoic boundary, a.k.a. P-T boundary.     He found out “superanoxia” (long-lasting deep-sea anoxia) and "Kamura event" (high productivity-cooling event in the Permian) in the superocean Panthalassa, and proposed a possible scenario called “Integrated Plume Winter” for explaining all unique geological phenomena relevant to the mass extinction.

Honors:
         1988 Young Scientist Award, Geological Society of Japan
         1992 Best Article Award, Geological Society of Japan
         1997 Koto Medal, Geological Society of Japan
         1999 Best Article Award, Geological Society of Japan
         2007 Geological Society Medal, Geological Society of Japan
         2007 Fellow, Geological Society of America
         2011 International Association of Gondwana Research, 2010 Best Paper Award

Major topics in his research

1) Establishing the research style on ancient accretionary complexes exposed on land by utilizing micropaleontological (conodont, radiolaria) and geochronological methods in Japan, Philippines, California, and Mexico. Further application is currently tested for much older units in Southern Siberia and Wales, UK.

A mode of subduction-accretion at trench and ocean plate stratigraphy
(Matsuda & Isozaki, 1991)

2) Clarifying the general structure of subduction-related (Cordilleran-type or Myashiro-type) orogenic belts composed of accretionary complex, high-P/T schists, and ophiolite (e.g., Japan).

SW Japan orogen composed of ancient accretionary complexes.
(Isozaki et al., 2010)

subhorizontal structure of accretionary complexes
with downward younging polarity (Isozaki et al., 2010)

3) Finding the mass extinction-related superanoxia (long-term oxygen- depletion) across the Paleozoic-Mesozoic boundary and the Kamura (high-productivity, cooling event) immediately before the Guadalupian-Lopingian boundary extinction, and also proposing the “Integrated Plume Winter” scenario for the greatest mass killing in history.

Integrated Plume Winter scenario (Isozaki, 2009b)
Check the Website of Discovery Channel
http://dsc.discovery.com/news/2008/12/12/magnetism-extinction.html

P-T boundary section at Chaotian, Sichuan, China (Isozaki et al., 2004)

　Middle Permian Illawarra Reversal (Isozaki, 2009a)

Gigantism in bivalves (Isozaki & Aljinovic, 2009)

Recent Publications (2006-2011)

Publications (pre-2006)

1) Tectonics

Maruyama, S., Isozaki, Y., Kimura, G. & Terabayashi, M., 1997: Paleogeographic maps of the Japanese Islands: Plate tectonic synthesis from 750 Ma to present.   The Island Arc, 6, 121-142

Isozaki, Y., 1997b: Jurassic accretion tectonics in Japan.   The Island Arc, 6, 25-51

Isozaki, Y., 1997a: Contrasting two types of orogen in Permo-Triassic Japan: accretionary versus collisional.   The Island Arc, 6, 2-24

Isozaki, Y., 1996b: Anatomy and genesis of a subduction-related orogen: A new view of geotectonic subdivision and evolution of the Japanese Islands.   The Island Arc, 5, 289-320

Kimura, G., Maruyama, S., Isozaki, Y. & Terabayashi, M., 1996: Well-preserved underplating structure of the jadeitized Franciscan complex, Pacheco Pass, California.   Geology, 24, 75-78

Isozaki, Y. & Blake, M.C.Jr., 1994: Biostratigraphic constraints on formation and timing of accretion in a subduction complex: An example from the Franciscan complex in northern California.   Jour. Geol., 102, 283-296

Matsuda, T. & Isozaki, Y., 1991: Well-documented travel history of Mesozoic pelagic cherts in Japan: from remote ocean to subduction zone.    Tectonics, 10, 475-499

Isozaki, Y., Maruyama, S. & Furuoka, F., 1990: Accreted oceanic materials in Japan.   Tectonophysics, 181, 179-205

Sedlock, R. & Isozaki, Y., 1990: Lithology and biostratigraphy of Franciscan-like chert and associated rocks in west-central Baja California, Mexico.   Geol. Soc. Amer. Bull., 102, 852-864.

Isozaki, Y. & Itaya, T., 1990: Chronology of Sanbagawa metamorphism.   Jour. Metamorph. Geol., 8, 401-411.

2) P-T Boundary, Mass extinction

Isozaki, Y., Yao, J.X., Matsuda, T., Sakai, H., Ji, Z.S., Shimizu, N., Kobayashi, N., Kawahata, H., Nishi, H., Takano, M. & Kubo, T., 2004: Stratigraphy of the Middle-Upper Permian and Lowermost Triasic at Chaotian, Sichuan, China - Record of end-Permian double mass extinction events-.   Proc. Japan Acad., 80B, 10-16

Matsuo, M., Kubo, K. & Isozaki, Y., 2003: Moessbauer spectroscopic study on characterization of iron in the Permian to Triassic deep-sea chert from Japan.   Hyperfine Interact. (C), 5, 435-438

Kato, Y., Nakao, K. & Isozaki, Y., 2002: Geochemistry of Late Permian to Early Triassic pelagic cherts from southwest Japan: implicationa for an oceanic redox change.   Chem. Geol., 182, 15-34

Isozaki, Y., 2001: An extraterrestrial impact at the Permian-Triassic boundary?   Science, 293, 2343

Musashi, M., Isozaki, Y., Koike, T. & Kreulen, R., 2001: Stable carbon isotope signature in mid-Panthalassa shallow-water carbonates across the Permo-Triassic boundary: evidence for 13C-depleted ocean.   Earth Planet. Sci. Lett., 191, 9-20.

Isozaki, Y. & Ota, A., 2001: Middle/Upper Permian (Maokouan/Wuchapingian) boundary in mid-oceanic paleo-atoll limestone in Kamura and Akasaka, Japan.   Proc. Japan Acad., 77B, 104-109

Bowring, S.A., Erwin, D.H. & Isozaki, Y., 1999: The Tempo of Mass Extinction and Recovery: The End-Permian Example.   Proc. Natl. Acad. Sci. USA, 96, 8827-8828

Isozaki, Y., 1997c: Permo-Triassic boundary Superanoxia and stratified superocean: Records from lost deep-sea.   Science, 276, 235-238

Isozaki, Y., 1994: Superanoxia across the Permo-Triassic boundary recorded in pelagic chert in Japan.   Canad. Soc. Petr. Geol.. Memoir,17, 805-812

3) Precambrian

Uchio, Y., Isozaki, Y., Ota, T., Utsunomiya, A., Buslov, M.M., & Maruyama, S, 2004: The oldest mid-oceanic carbonate buildup complex: setting and lithofacies of the Vendian (Neoproterozoic) Baratal limestone in the Gorny Altai Mountains, Siberia.   Proc. Japan Acad. 80B, 422-428

Ueno, Y., Yoshioka, H., Maruyama, S. & Isozaki, Y., 2004: Carbon isotopes and petrography of 13C-depleted kerogen in ca. 3.5 Ga hydrothermal silica dikes in the North pole area, Western australia: implications for the early life in the Archean sub-seaflor.   Geochim. Cosmochim. Acta, 68, 573-589

Ueno, Y., Isozaki, Y., Yurimoto, H. & Maruyama, S., 2001: Carbon isotopic signatures of individual Archean microfossils(?) from Western Australia.   Intern. Geol. Rev., 43, 196-212

Kato, Y., Ohta, I., Tsunematsu, T., Watanabe, Y., Isozaki, Y., Maruyama, S. & Imai, N., 1998: Rare earth element variations in mid-Archean banded iron formations: implications for the chemistry of ocean and continent and plate tectonics.   Geochi. Cosmochi. Acta, 62, 3475-3497