Japan Geoscience Union Meeting 2019

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[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-GI General Geosciences, Information Geosciences & Simulations

[M-GI34] Marine Manganese Minerals

Tue. May 28, 2019 3:30 PM - 5:00 PM A09 (TOKYO BAY MAKUHARI HALL)

convener:Akira Usui(Marine Core Research Center, Kochi University), Yoshio Takahashi(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Katsuhiko Suzuki(Research and Development Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology), Takashi Ito(Faculty of Education, Ibaraki University), Chairperson:takashi ito(Ibaraki Univ.), Yoshio Takahashi(東京大学), Katsuhiko Suzuki(JAMSTEC)

3:30 PM - 3:45 PM

[MGI34-01] Challenges in microstratigraphy on the hydrogenetic ferromanganese crusts: Depositional processes and environments recorded as secular variations in microstructure, chemical and mineralogical compositions.

*Akira Usui1, Anna Nagaoka2, Go-Ichiro Uramoto1, Masafumi MURAYAMA3 (1.Marine Core Research Center, Kochi University, 2.Graduate School of Science, Kochi University, 3.Fac. Agriculture and Marine Sciences, Kochi University)

Keywords:marine manganese deposit, manganese crust, microstratigraphy, Shima-Shima-gaku

We attempted to apply the method of Shima-Shima-gaku (lamina stratigraphy named by prof. S. Kawakami) on the secular variations in growth structure, chemical and mineralogical properties between the growth columns of the hydrogenetic ferromanganese deposit. The critera for describing each bands or zones based on the macroscopic (=physical) properties are not always consistant with chronological correlations or may not match with mineral/chemical composition. Our microscopic characterization using optical microscope, XRF mapping, XRD, acid-leach, micro-focus X-ray CT proved a possibility of separating local and regional sources of each mineral particle or element which is closely associated the environments of eposition.