Identification of primary producers in the early oceans

2014 Fiscal Year Final Research Report

• Project/Area Number: 24403013
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 海外学術
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: Tohoku University
• Principal Investigator: KAKEGAWA Takeshi 東北大学, 理学(系)研究科(研究院), 教授 (60250669)
• Co-Investigator(Kenkyū-buntansha): HASHIZUME Ko 大阪大学, 大学院理学研究科, 助教 (90252577) ; NAGASE Toshirou 東北大学, 学術資源研究公開センター, 准教授 (10237521)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 一次生産者 / 初期地球 / イスア / バーバートン / スティープロック

Outline of Final Research Achievements

The purposes of the present study are to constrain biological primary producers in 3.8, 3.2, and 3.0 Ga oceans. To approach the purpose, we performed geological surveys in Isua (Greenland), Barberton (S. Africa), and Steep Rock and Lumby Lake (Canada). Besides the detailed geological data, mineralogical and geochemical data suggest that cyanobacteria were the primary producers at least since 3.0 Ga. In addition, chemoautotrophic and heterotrophic bacteria, whose activities were supported by cyanobacteria indirectly, were also active in deep sedimentary basin. We also discovered new evidence for trace of the earliest life in rocks from Isua. This discovery was broadcasted widely through various media. Other results were reported at the major international conferences. Some papers are in reviews at major international journals.

Free Research Field

地球化学