Concentration and isotope ratio of ammonia in ancient oceans

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03741
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geology
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: NISHIZAWA Manabu 国立研究開発法人海洋研究開発機構, 深海・地殻内生物圏研究分野, 研究員 (60447539)
• Co-Investigator(Kenkyū-buntansha): 渋谷 岳造 国立研究開発法人海洋研究開発機構, 深海・地殻内生物圏研究分野, 研究員 (00512906)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: アンモニア / 濃度 / 窒素同位体比 / 古海洋

Outline of Final Research Achievements

Though ammonia is a key reactant for the synthesis of cellular materials, ammonia concentrations in the early oceans are largely unknown. The purpose of this study is to reconstruct ammonia concentrations in the early oceans from that in minerals in Archean oceanic crusts. We have newly developed the methodologies for separation of tiny minerals from archean basalts and for quantification of concentrations and isotope ratios of ammonium in separated minerals at the nanomole level. We find that the separated minerals preserve ammonium in seawater origin. Experiments for water-rock interaction in the presence of ammonium also support that oceanic crusts preserve ammonium in seawater origin.

Free Research Field

地球化学