Molecular/atomic-level analysis of metal-bearing compounds for in-situ proxy of marine biogeochemical cycling

• Project/Area Number: 26610187
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Geochemistry/Cosmochemistry
• Research Institution: The University of Tokyo (2015); Japan Agency for Marine-Earth Science and Technology (2014)
• Principal Investigator: Yoshimura Toshihiro 東京大学, 大気海洋研究所, 助教 (90710070)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2015: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2014: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 有機金属化合物

Outline of Final Research Achievements

The amount of bioessential metals play a key role in marine biogeochemical processes as a limiting factor for vital reactions. Quantitative analysis of metal-bearing compounds may be able to indicate in situ proxy for biological activity. I measured down-core data of bioessential metals (Fe, An, Cu, Mn, Mo), and radiogenic Sr isotope ratios in a Quaternary sediment core recovered from the West Caroline Basin in the western equatorial Pacific. Following chromatographic separation of lipid, protein, and pigment fractions, metal concentrations were measured with a quadrupole inductively coupled plasma mass spectrometer. I also measured dense benthic microbial mat of solar salterns which harbor surprisingly diverse microorganisms. The in situ geochemical signatures and sediment fabrics of salt deposits allows proposing a past depositional environment with marked impact on the benthic biota of the depositional basin.

Research Products

• [Int'l Joint Research] モデナ・レッジョ・エミリア大学/パルマ大学(イタリア)
• [Journal Article] An X-ray spectroscopic perspective on Messinian evaporite from Sicily: sedimentary fabrics, element distributions, and chemical environments of S and Mg (2016)
  • Author(s): Toshihiro Yoshimura, Junichiro Kuroda, Stefano Lugli, Yusuke Tamenori, Nanako O. Ogawa, Francisco J. Jiménez-Espejo, Yuta Isaji, Marco Roveri, Vinicio Manzi, Hodaka Kawahata, Naohiko Ohkouchi
  • Journal Title: Geochemistry Geophysics Geosystems Volume: 17 Issue: 4 Pages: 1-18
  • DOI: 10.1002/2015gc006233
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] 海洋におけるカルシウムの地球科学と安定同位体指標 (2016)
  • Author(s): 吉村 寿紘，井上 麻夕里
  • Journal Title: 海の研究 Volume: 25 Pages: 81-99
  • NAID: 40020880077
  • Peer Reviewed
• [Presentation] A Quaternary δ88/86Sr record from planktonic foraminifera in equatrial Pacific sediment of West Caroline Basin (2016)
  • Author(s): Toshihiro Yoshimura, Shigeyuki Wakaki, Junichiro Kuroda, Toshitsugu Yamazaki, Haruka Takagi, Katsunori Kimoto, Yuki Sakuramoto, Tsuyoshi Ishikawa, Naohiko Ohkouchi
  • Organizer: 26th Goldschmidt Conference
  • Place of Presentation: パシフィコ横浜、横浜市
  • Year and Date: 2016-06-26
  • Int'l Joint Research
• [Presentation] Effect s of increasing salinity on the biogeochemical cycle of the hypersaline bio mat: Insights from the isotop ic composition of pigments (2016)
  • Author(s): Yuta Isaji, Hodaka Kawahata, Junichiro Kuroda, Toshihiro Yoshimura, Nanako O. Ogawa, Atsushi Suzuki, Takazo Shibuya, Stefano Lugli, Yusuke Tamenori, Nanako O. Ogawa, Francisco J. Jimenez-Espejo, Stefano Lugli, Vinicio Manzi, Marco Roveri, Naohiko Ohkouchi
  • Organizer: 26th Goldschmidt Conference
  • Place of Presentation: パシフィコ横浜、横浜市
  • Year and Date: 2016-06-26
  • Int'l Joint Research
• [Presentation] Isotope ana lysis of ng-sized Nd by total evaporation TIMS and its application to foraminifera samples (2015)
  • Author(s): Shigeyuki Wakaki, Toshihiro Yoshimura, Junichiro Kuroda, Naohiko Ohkouchi, Tsuyoshi Ishikawa
  • Organizer: 25th Goldschmidt Conference
  • Place of Presentation: プラハ、チェコ
  • Year and Date: 2015-08-15
  • Int'l Joint Research
• [Presentation] Carbon and nitrogen stable isotope measurements and X-ray photoabsorption spectroscopy of microbial-mat-containing gypsum crust in modern saline pan (2015)
  • Author(s): Yuta Isaji, Hodaka Kawahata, Toshihiro Yoshimura, Junichiro Kuroda, Nanako O. Ogawa, Atsushi Suzuki, Takazo Shibuya, Stefano Lugli, Yusuke Tamenori, Nanako O. Ogawa, Francisco J. Jimenez-Espejo, Stefano Lugli, Vinicio Manzi, Marco Roveri, Yusuke Tamenori, Naohiko Ohkouchi
  • Organizer: European Geosciences Union General Assembly 2015
  • Place of Presentation: ウィーン、オーストリア
  • Year and Date: 2015-04-12
  • Int'l Joint Research