Characterization and genesis of mantle compositional hemispheres

2016 Fiscal Year Final Research Report

• Project/Area Number: 26247091
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Iwamori Hikaru 国立研究開発法人海洋研究開発機構, 地球内部物質循環研究分野, 分野長 (80221795)
• Co-Investigator(Kenkyū-buntansha): 横山 哲也 東京工業大学, 理工学研究科, 准教授 (00467028) ; 中村 仁美 国立研究開発法人海洋研究開発機構, 地球内部物質循環研究分野, 研究員 (60572659)
• Co-Investigator(Renkei-kenkyūsha): Hanyu Takeshi 国立研究開発法人海洋研究開発機構, 地球内部物質循環研究分野, 主任研究員 (50359197)
• Research Collaborator: Tatiana Churikova ; Boris Gordeychik ; Asobo Asaah ; Festus T. Aka ; Shimizu Kenji ; Nishizawa Tatsuji ; Ozawa Takahiro
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: マントル / 組成 / 同位体 / 半球構造 / 統計解析 / 独立成分分析 / 水 / 物質循環

Outline of Final Research Achievements

Geochemical heterogeneity in the Earth’s mantle has been investigated based on the Quaternary basalts over the globe. With a special attention to recently proposed “east-west mantle geochemical hemispheres”, (1) detailed inspection along the hemisphere boundary, (2) Independent Component Analysis of global geochemical data, and (3) numerical simulation of water-bearing mantle convection have been performed. As a result, it has been revealed that (A) the eastern hemisphere is relatively enriched in hydrophile components, and (B) the hemispherical structure extends from the near-surface to the inner core via “top-down hemispherical dynamics” in which the supercontinent and focused subduction towards it could have created the global hemispherical structure.

Free Research Field

地質学