Development of zircon pre-crystallization magma resident time dating for investigation of high-temperature magma processes

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K13636
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 17040:Solid earth sciences-related
• Research Institution: The University of Tokyo (2019-2021); Gakushuin University (2018)
• Principal Investigator: Sakata Shuhei 東京大学, 地震研究所, 助教 (20772255)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: マグマの上昇速度 / ジルコン / 放射年代学 / 地球化学

Outline of Final Research Achievements

The mineral zircon, which is found in magma-solidified rocks observed on the earth's surface. Zircon can be dated using isotopes of uranium, thorium, and lead to determine the time from its crystallization to the present. In this study, we took the conventional method one step further and developed a method to quantify the time before the mineral crystallization by combining the age calculated from thorium-lead pairs and the age obtained from uranium and lead. This method is expected to allow us to determine the time from when magma generated deep underground rises to the surface to when minerals are formed along the way.

Free Research Field

地球年代学

Academic Significance and Societal Importance of the Research Achievements

日本は世界有数の火山大国であり、火山噴火のメカニズムを明らかにすることは学術的にも防災の観点からも重要である。しかし、火山地下のマグマ溜まりよりさらに下部、すなわち「火山の根」がどうなっているのかについては未だ不明な点が多い。本研究は火山の根においてマグマが上昇するスピードの履歴を鉱物に保存される情報から読み取ろうとするもので、火山の地下でのマグマの動きに関する直接的な証拠を提供すると期待される。