Japan Geoscience Union Meeting 2015

Presentation information


Symbol B (Biogeosciences) » B-CG Complex & General

[B-CG28] Interrelation between Life, Water, Mineral, and Atmosphere

Tue. May 26, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Fumito Shiraishi(Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University), Tsubasa Otake(Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University), Yohey Suzuki(Graduate School of Science, The University of Tokyo), Ken Takai(Extremobiosphere Research Center, Japan Agency for Marine-Earth Science & Technology), Yuichiro Ueno(Department of Earth and Planetary Sciences, Tokyo Institute of Technology), Takeshi Naganuma(Graduate School of Biosphere Science), Takeshi Kakegawa(Graduate School of Science, Tohoku University), Tadashi Yokoyama(Department of Earth and Space Science, Graduate School of Science, Osaka University), Kentaro Nakamura(Precambrian Ecosystem Laboratory (PEL), Japan Agency for Marine-Earth Science and Technology (JAMSTEC))

6:15 PM - 7:30 PM

[BCG28-P15] Mineralogical and geochemical study of marine sedimentary rocks of Gunflint Formation(1.9 Ga), Ontario, Canada

*Emi NIKAIDO1, Fumiko NARA1, Noriyoshi TSUCHIYA2, Takeshi KAKEGAWA1 (1.Graduate School of Science, Tohoku University, 2.Graduate School of Environmental studies, Tohoku University)

Gunflint Formation is composed of marine sedimentary rocks, which deposited at ca.1.9 to 1.8 Ga. Disappearance of banded iron formation and Sudbury meteorite impact occurred during the sedimentation of Gunflint Formation. However, impacts of those geological events on ecology were not evaluated in past. Therefore, in the present study, geochemical studies are performed.

Concentration patterns of Fe are different from lowermost to upper sections. Such change is corresponded to disappearance of BIF, thus decrease of Fe flux in shallow sediments. Compositions of kerogen were similar through the entire sections. However, a section which recorded Sudbury impact shows variable N/C ratios of kerogen. This may suggest that nitrogen cycle through atmosphere, hydrosphere and biosphere changed temporarily right after meteorite impact.