Kyushu University Academic Staff Educational and Research Activities Database
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Yasuhito Osanai Last modified date:2019.07.25

Graduate School
Undergraduate School
Other Organization
Administration Post
Dean of the School of Interdisciplinary Science and Innovation
Vice President

Academic Degree
Doctor of Science
Country of degree conferring institution (Overseas)
Field of Specialization
Geology, Petrology
Total Priod of education and research career in the foreign country
Outline Activities
Recent major subject is evolution and tectonics of Continental crust, which is studied through UNESCO-IGCP programs and international collaborations (eg. SEAL project), and advanced collaboration researches with Archeology including following topics;
(1) Origin and evolution of Earth's oldest rock studied using ultrahigh-temperature metamorphic rocks from circum Indian Ocean (Antarctica, India, Sri Lanka, Madagascar, Mozambique, South Africa, Australia).
(2) Evolution of extreme conditioned metamorphic rocks (Ultrahigh temperature and ultrahigh pressure) to understanding the lower crustal processes.
(3) Granite magma genesis and evolution of continental crust
(4)Tectono-metamorphic processes of East and South-East Asia including Japanese domestic metamorphic terranes.
(5) Tectonic evolution of Antarctic continental crust.
(6) Collaboration researches with Archeology using advanced analytical facilities/techniques.
Research Interests
  • Development of interdisciplinary research between Archeology and Earth Sciences on the basis of Petrology, Mineralogy and Isotope Geochemistry
    keyword : Earth Sciences, Archeology, Interdisciplinary Research
Current and Past Project
  • Geological and Tectonic Evolution of Gondwana Super Continent through the geological and petrological studies at Sor Rondane Mountains in Antarctica.
Academic Activities
1. M. Satish-Kumar, Y. Motoyoshi, Y. Osanai, Y. Hiroi and K. Shiraishi, Geodynamic Evolution of East Antarctica: a Key to the East-West Gondowana Connection, Geological Society of London, 300, 2008.11.
1. Yasuhito Osanai, Krishnan Sajeev, Nobuhiko Nakano, Ippei Kitano, Wilbert K.V. Kehelpannala, Ryosuke Kato, Tatsuro Adachi, Sanjeewa P.K. Malaviarachchi, UHT granulites of the Highland Complex, Sri Lanka II
Geochronological constraints and implications for Gondwana correlation, Journal of Mineralogical and Petrological Sciences, 10.2465/jmps.151230, 111, 3, 157-169, 2016.07, The regional ultrahigh-temperature (UHT) metamorphism of the Highland Complex, Sri Lanka is well established and has an important role in our understanding of the tectonic history of the Gondwana supercontinent. U-Pb zircon dating of sapphirine-bearing Mg-Al granulites yielded two major metamorphic age populations at approximately 620-590 and 563-525 Ma with no evidence of older zircon cores. Pelitic granulite samples with a Grt-Sil-Spl-Crd assemblage have similar metamorphic ages with concordant data clusters at ~ 602, 563, and 526 Ma and inherited zircon cores aged from 2040 to 1600 Ma. The pelitic granulites also underwent two stages of metamorphism (565-520 and 622-580 Ma). Some of these pelitic granulite samples have inherited zircon cores ranging from 3060 to 760 Ma. Zircons in mafic granulite samples have age ranges of 566-533 and 620-578 Ma. A calc-silicate granulite sample also has similar age populations at 591, 541, and 524 Ma. Combining these new results with previously published ages from Sri Lanka and formerly adjacent continental fragments of Gondwana, we propose that the terranes in southern Madagascar (south of Ranotsara Shear Zone), Northern and Southern Madurai and the Trivandrum Blocks of southern India, the Highland Complex of Sri Lanka, and the Skallen Group in the Lützow-Holm Complex of East Antarctica represent a unique metamorphic belt that regionally experienced the Ediacaran-Cambrian UHT event during the amalgamation of the Gondwana supercontinent..
2. Yasuhito Osanai, Krishnan Sajeev, Nobuhiko Nakano, Ippei Kitano, Wilbert K.V. Kehelpannala, Ryosuke Kato, Tatsuro Adachi, Sanjeewa P.K. Malaviarachchi, UHT granulites of the Highland Complex, Sri Lanka I
Geological and petrological background, Journal of Mineralogical and Petrological Sciences, 10.2465/jmps.151227, 111, 3, 145-156, 2016.07, The ultrahigh-temperature (UHT) regional metamorphism of Sri Lanka has a significant role in understanding the tectonics and formation of the Gondwana supercontinent. Sri Lanka is specifically important because of its central position in Gondwana, located between southern India, Madagascar and eastern Antarctica. In particular, the Highland Complex has been the focus of several previous studies because of the prominence of metasedimentary rocks that experienced UHT metamorphism. The central Highland Complex of Sri Lanka consists of Spr-bearing Mg-Al rich granulites intercalated with other pelitic, mafic granulites and calc-silicates, which preserve several textural evidences for UHT metamorphism. The calculated peak metamorphic conditions for the Mg-Al rich granulite yielded a temperature range from 910 to 1005 °C at 1.0 GPa, and the pressure varies between 0.9 to 1.2 GPa. The estimated metamorphic P-T conditions and evolution path is in good agreement with previous studies and also to that of similar rock-types from southern Madagascar, southern India and East Antarctica..
3. Yasuhito Osanai, Yoshifumi Nogi, Sotaro Baba, Nobuhiko Nakano, Tatsuro Adachi, Tomokazu Hokada, Tsuyoshi Toyoshima, Masaaki Owada, M. Satish-Kumar, Atsushi Kamei, Ippei Kitano, Geologic evolution of the Sør Rondane Mountains, East Antarctica: Collision tectonics proposed based on metamorphic processes and magnetic anomalies, Precambrian Research, 234, 8-29, 2013.09.
4. Sajeev Krishnan, Ian S. Williams, Yasuhito Osanai, SHRIMP U-Pb dating of prograde and retrograde UHT metamorphism as exemplified by Sri Lankan granulites, Geology, 38, 971-974, 2010.10.
5. M. Satish-Kumar, J. Hermann, Tomoharu Miyamoto, Yasuhito Osanai, Fingerprinting a multistage metamorphic fluid-rock history: Evidence from grain scale Sr, O and C isotopic and trace element variations in high-grade marbles from East Antarctica, Lithos, 114, 217-228, 2010.05.
6. Nobuhiko Nakano, Yasuhito Osanai, Sajeev Krishnan, Yasutaka Hayasaka, Tomoharu Miyamoto, Minh Thi Nguyen, Masaaki Owada, Brian Windley, Triassic eclogite from northern Vietnam: inferences and geological significance. , Jour. Metamorphic Geol., 28, 59-76, 2010.01.
7. Nobuhiko Nakano, Yasuhito Osanai, Masaaki Owada, Yasutaka Hayasaka, Tran Ngoc Nam, Permo-Triassic Barrovian metamorphism in the Kontum Massif, central Vietnam: constraints on continental collision tectonics in Southeast Asia, Island Arc, 18, 126-143., 2009.01.
8. Toyoshima, T., Osanai, Y. and Nogi, Y., Macroscopic geological structures of the Napier and Rayner Complexes, East Antarctica, Geological Society of London, Special Publications, 308, 139-146., 2008.11.
9. Kawasaki, T. and Osanai, Y., Empirical thermometer of TiO2 in quartz for ultrahigh-temperature granulites of East Antarctica, Geological Society of London, Special Publications, 308, 419-430., 2008.11.
10. Osanai, Y., Nakano, N., Owada, M., Tran Ngoc Nam, Miyamoto, T., Nguyen Thi Minh, Nguyen Van Nam and Tran Van Tri, Collision zone metamorphism in Vietnam and adjacent South-eastern Asia: Proposition for Trans Vietnam Orogenic Belt, Jour. Mineral. Petrol. Sci., 103, 226-241., 2008.08.
11. Nakano, N., Osanai, Y., Minh, N.T., Miyamoto, T., Hayasaka, Y. and Owada, M., Discovery of high-pressure granulite-facies metamorphism in northern Vietnam: Constraints on the Permo-Triassic Indochinese continental collision tectonics, Compites Rndus Geoscience, 340, 127-138, 2008.01.
12. Nakano, N., Osanai, Y. and Owada, M., Multiple breakdown and chemical equilibrium of silicic clinopyroxene under extreme metamorphic conditions in the Kontum Massif, central Vietnam, American Mineralogist, 92, 1844-1855, 2007.10.
13. Sajeev, K., Osanai, Y., Connolly, J.A.D., Suzuki, S., Ishioka, J., Kagami, H. and Rino, S, Extreme Crustal Metamorphism during a Neoproterozoic Event in Sri Lanka: A Study of Dry Mafic Granulites, Journal of Geology, 115, 563-582, 2007.03.
14. Osanai, Y., Sajeev, K., Owada,M., Kehalpannala, K.V.W., Prem, W.K.B., Nakano, N. and Jayatileke, S., Metamorphic evolution of ultrahigh-temperature and high-pressure granulites from the Highland Complex, Sri Lanka, Journal of Asian Earth Science, 28, 20-37., 2006.06.
15. Osanai, Y., Owada, M., Kamei, A., Hamamoto, T., Kagami, H., Toyoshima, T., Nakano, N. and Tran Ngoc Nam, The Higo metamorphic complex in Kyushu, Japan as the fragment of Permo-Triassic metamorphic complexes in East Asia., Gondwana Res., 9, 152-166., 2006.01.
16. Sajeev, K. and Osanai, Y., Thermal gradients in the Sri Lankan granulite terrane: a garnet-biotite thermometric approach., J. Metamorphic Geol., 10.1111/j.1525-1314.2005.00582.x, 23, 5, 383-397, 23, 383-397., 2005.07.
17. Sajeev, K., Osanai, Y. and Santosh, M., Ultrahigh-temperature metamorphism followed by two-stage decompression of Grt-Opx-Sil granulites from Ganguvarpatti, Madurai block, southern India, Contrib. Mineral. Petrol., 10.1007/s00410-004-0592-0, 148, 1, 29-46, 148, 29-46, 2004.10.
18. Osanai, Y., Nakano, N., Owada, M., Tran, N. Nam, Toyoshima, T., Tsunogae, T. and Binh, P., Permo-Triassic ultrahigh-temperature metamorphism in the Kontum massif, central Vietnam, Jour. Mineral. Petrol. Sci., 10.2465/jmps.99.225, 99, 4, 225-241, 99, 230-247., 2004.07.
1. Osanai, Y., Nakano, N., Owada, M., Pham Binh, Tran Van Tri, Charusiri, P., Tran Ngoc Nam, Tectonic evolution of extreme metamorphic rocks in the Trans Vietnam Origenic Belt, SE-Asia, GEOSEA XV, 2018.10.
  • Honorary Geologist of Mongolia
  • Metamorphic evolution of Kontum Massif in central Vietnam
Educational Activities
School of Interdisciplinary Science and Innovation
(Undestanding the Earth, Earth Environment, Earth Material Science, Degree Project 1, Degree Project 2, Degree Project 3),

Graduate School of Social and Cultural Studies:
Post-graduate: lectures and field training on advanced metamorphic petrology and structural geology
Graduate: lectures and field training on metamorphic petrology and structural geology
Graduate School of Integrated Sciences for Global Society:
Evolution of Crustal Materials, Comprehensive Earth Sciences A, Integrated Seminar (Earth Sciences),
Undergraduate: lectures on Earth environments and field training on basic geology, mineralogy and petrology

Other Universities:
Special lectures on evolution of continental crusts, extreme metamorphism, Antarctic earth sciences, etc in Kyushu, Ehime, Osaka-City, Okayama, Yamaguch, Niigata, Hiroshina, Yokohana National, Yamagata, Kobe, Kanazawa, Tohoku and the other universities."""
Professional and Outreach Activities
・Public lectures on Antarctic Earth Sciences and Evolution of Natural Environments in Gondwana and East Asia
(Kurashiki city, Okayama prefecture, Okayama University, High/Junior High Schools)"""
・Deputy leader of 49th Japanese Antarctic Research Expedition.