Redox state of arc magma, inferred from sulfur speciations of melt inclusions

2015 Fiscal Year Final Research Report

• Project/Area Number: 25610160
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Shimizu Kenji 国立研究開発法人海洋研究開発機構, 高知コア研究所, 技術研究員 (30420491)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 島弧火山岩 / 酸化還元状態 / メルト包有物 / 硫黄化学形態

Outline of Final Research Achievements

Redox state of the Earth's interior influences on its physical properties and redox sensitive elements (e.g. chalcophiles, siderophiles). Redox state of mantle beneath a subduction zone (wedge mantle), which is the only place where the material on the surface is brought to the deep mantle, is essential to understand the global material cycles, but its estimation is highly controversial. In order to evaluate redox state of wedge mantle, we analyzed sulfur speciation (highly sensitive to redox state) of primitive melt inclusions within Cr-spinel from arc volcanic rocks by soft X-ray microbeam at SPring-8. As a result, we indicate that wedge mantle is oxidized. We expect that we are able to constrain the element enrichment processes at subduction zone.

Free Research Field

地球化学