Kyushu University Academic Staff Educational and Research Activities Database
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Junichiro Ishibashi Last modified date:2018.06.18

Associate Professor / Material Science of Solar Planets
Department of Earth and Planetary Sciences
Faculty of Sciences


Graduate School
Undergraduate School
Other Organization


E-Mail
Phone
092-802-4215
Fax
092-802-4208
Academic Degree
D. Sc.
Country of degree conferring institution (Overseas)
No
Field of Specialization
Resource Geochemistry, Ocean Science
Total Priod of education and research career in the foreign country
00years03months
Outline Activities
1) Geochemical characteristics of hydrothermal systems in arc-backarc setting
2) Time-series study of magmatic contribution to hydrothermal systems
3) Geochemical processes during hydrothermal plume generation process
4) Chemical environment of active hydrothermal fields and its relationship
with sub-vent biosphere
5) Ore formation mechanism based on fluid and mineral geochemical studies
Research
Research Interests
  • Chronological studies of hydrothermal ore deposits
    keyword : ESR dating
    2008.04.
  • Formation process of volcanic massive sulfide ore
    keyword : submarine hydrothermal deposit, phase separation, seafloor drilling
    2007.10.
  • Geochemical studies of submarine hydrothermal system
    keyword : hydrothermal circulation, chemosynthesis, hydrothermal alteration
    1985.04Geochemical Studies of submarine hydrothermal systems.
  • Geochemical studies of hot springs related with magmatic activity
    keyword : geothermal systems, magmatic volatiles
    1998.11Geochemical Studies of hot springs in Kyushu.
Current and Past Project
  • Project TAIGA: Trans-crustal Advection and In-situ biogeochemical processes of Global sub-seafloor Aquifer
  • Arc Hydrothermal Drilling
  • Deep Hot Biosphere
  • International research project on Interaction between sub-vent biosphere and geo-environment
Academic Activities
Books
1. Junichiro Ishibashi, Kyoko Okino, Michinori Sunamura, Subseafloor Biosphere Linked to Hydrothermal Systems, Springer Japan, 10.1007/978-4-431-54865-2, pp.666, 2015.01, [URL], This book is the comprehensive volume of the TAIGA (“a great river ” in Japanese) project. Supported by the Japanese government, the project examined the hypothesis that the subseafloor fluid advection system (subseafloor TAIGA) can be categorized into four types, TAIGAs of sulfur, hydrogen, carbon (methane), and iron, according to the most dominant reducing substance, and the chemolithoautotrophic bacteria/archaea that are inextricably associated with respective types of TAIGAs which are strongly affected by their geological background such as surrounding host rocks and tectonic settings. Sub-seafloor ecosystems are sustained by hydrothermal circulation or TAIGA that carry chemical energy to the chemosynthetic microbes living in an extreme environment. The results of the project have been summarized comprehensively in 50 chapters, and this book provides an overall introduction and relevant topics on the mid-ocean ridge system of the Indian Ocean and on the arc-backarc systems of the Southern Mariana Trough and Okinawa Trough..
Reports
1. Interactions between lithosphere, hydrosphere, and biosphere through the hydrothermal fluid circulation system beneath the seafloor.
2. A new model for a hydrothermal circulation system and limit of the life.
Papers
1. Ishibashi, J.-I., M. Nakaseama, M. Seguchi, T. Yamashita, S. Doi, T. Sakamoto, K. Shimada, N. Shimada, T. Noguchi, T. Oomori, M. Kusakabe, T. Yamanaka, Marine shallow-water hydrothermal activity and mineralization at the Wakamiko crater in Kagoshima bay, south Kyushu, Japan., Journal of Volocanology and Geothermal Research, 10.1016/j.jvolgeores.2007.12.041, 173, 84-98, 2008.05.
Presentations
1. Jun-ichiro Ishibashi, Are Seafloor Massive Sulfides a modern analogue for VMS deposit ?, Goldschmidt Conference 2016, 2016.06, Seafloor massive sulfides recognized in hydrothermal fields in arc-backarc settings in the western Pacific are commonly represented by coexisting occurrence of zinc- and lead-enriched polymetallic sulfides and abundant sulfate minerals. The mineralogy and geochemical signatures present has led researchers to suggest these areas may be a modern analogue for the formation of ancient Kuroko-type volcanogenic massive sulfide (VMS) deposits. Seafloor drilling during IODP (Integrated Ocean Drilling Program) Expedition 331 documented the subseafloor hydrothermal system at the Iheya North Knoll in the Okinawa Trough. Mineral textures and assemblages present in the drilled cores obtained from a hydrothermal mound in the proximal area were consistent with those recognized in ancient Kuroko-type mineralization. Moreover, stratabound occurrences of base-metal mineralization and widespread hydrothermal alteration were recognized across an area of over 500 m extent, which are comparable to ancient Kuroko-type deposits. On the other hand, geochemical studies of hydrothermal fluid venting from the seafloor and pore fluid within the sediment demonstrated diverse range of sulfide and sulfate mineralization could be related to subseafloor geochemical processes and fluid flows. Geochemical studies on present seafloor hydrothermal activities would provide a rare window into the dynamic processes for formation of VMS deposits..
Membership in Academic Society
  • Society of Economic Geologists
  • American Geophysics Union
Social
Professional and Outreach Activities
InterRidge Steering Committee member (2007.1 - ).