The rate of dehydration of the stagnant slab in the mantle transition zone

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13900
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Hokkaido University
• Principal Investigator: Kuritani Takeshi 北海道大学, 理学研究院, 准教授 (80397900)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: マグマ / 水循環 / マントル遷移層 / 停滞スラブ / プレート内火成活動

Outline of Final Research Achievements

Geophysical observation has suggested that the mantle transition zone beneath NE China is hydrous, and the subducted Pacific slab is stagnated in the transition zone. To estimate the rate of the dehydration of the stagnant slab, petrological and geochemical analyses were conducted on volcanic rocks of variable ages (60-0 Ma) above the stagnant slab. Unfortunately, the rate of the dehydration could not have been estimated because of no significant temporal variation in the water contents of the source mantle. However, this study showed that the mantle transition zone have been hydrous between 60 and 0 Ma. In addition, this study proposed a general model about the origin of the intraplate magmatism over the stagnant slab.

Free Research Field

火山岩岩石学