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Updated: Jul 4, 2026

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Atom Probe Tomography Analysis of Exsolved Mineral Phases
Published on: October 25, 2019
キラウエア・イキの溶岩湖におけるマグマ的分化中の鉄同位体の分化
Fang-Zhen Teng1, Nicolas Dauphas, Rosalind T Helz
1Origins Laboratory, Department of the Geophysical Sciences and Enrico Fermi Institute, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637, USA. fteng@uark.edu
まとめ
鉄のイソトープは,マグマ的分化時に分化し,マグネシウムやリチウムとは異なり,分化します. ハワイの玄武岩で観察されたこの鉄同位体の分断は,惑星の分化プロセスに関する新しい洞察を提供します.
科学分野:
- 地質化学 地質化学
- イソトープ地球化学 イソトープ地球化学
- ペトロロジー・ペトロロジーとは
背景:
- マグマ的差異化は,陸上の岩の多様性を駆動する.
- 微分化の過程で非放射性同位体の分断は,すべての元素について完全に理解されていません.
研究 の 目的:
- マグマ的微分化の過程における鉄同位体の分断を調査する.
- キラウエア・イキの溶岩湖 (ハワイ) の玄武岩の鉄同位体を分析するために.
主な方法:
- 末期溶解静脈とオリヴィン累積物における鉄同位体組成 (56Fe/54Fe) の分析.
- 岩石全体,溶融脈,オリヴィン系フェノクリスタル間の同位体値の比較.
主要な成果:
- 末期溶解静脈では,オリビンの累積物より56Fe/54Fe比率が高 (0.2パーミル) である.
- オリビンのフェノクリスタには,鉄の同位体成分が軽く (1.2パーミルまで) 整体岩と比較して見られます.
- 鉄イソトープの分断を全岩と結晶のスケールで実証した.
結論:
- 鉄のイソトープは,マグマ的分化中に分化し,これはマグネシウムやリチウムには観察されていない特徴です.
- 鉄の複雑なリドックス化学は,磁気系における同位体分化に影響を与える可能性が高い.
- 鉄イソトープは,惑星の微分化を研究するための新たなツールとなる可能性がある.
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