Elemental behavior in the hydrothermal alteration of ophiolite oceanic crust

2020 Fiscal Year Final Research Report

• Project/Area Number: 15K17790
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Yamaoka Kyoko 国立研究開発法人産業技術総合研究所, 地質調査総合センター, 主任研究員 (30610399)
• Project Period (FY): 2015-03-01 – 2021-03-31
• Keywords: 海洋地殻 / 熱水変質 / 微量元素 / 同位体

Outline of Final Research Achievements

Major and trace element analyses of the Cretaceous oceanic crust, the Oman ophiolite, were carried out to complete a comprehensive chemical compositional profile of a cross section of the oceanic crust from the ocean floor to the Moho surface. Based on the secondary mineral compositions and isotopic compositions of strontium, oxygen, and boron already reported for this sample set, the reaction conditions and elemental behavior of hydrothermal alteration were analyzed, and the mass balance in hydrothermal alteration from low to high temperatures was quantitatively estimated.

Free Research Field

地球化学

Academic Significance and Societal Importance of the Research Achievements

熱水変質した海洋地殻の化学組成は、海洋及び固体地球の化学進化を理解するために不可欠であるにも関わらず、掘削の困難さから、実際の海洋地殻から得られる情報は断片的であった。本研究ではオフィオライトをアナログとして、海洋地殻層序全体の化学組成プロファイルを明らかにし、全球的な物質循環に関して重要なリファレンスデータを提供することが出来た。