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Updated: Mar 15, 2026
08:14
Atom Probe Tomography Analysis of Exsolved Mineral Phases
Published on: October 25, 2019
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HIMU パズルの重要な新しいピースは,オリビンとダイヤモンドインクルージョンから
Yaakov Weiss1, Cornelia Class1, Steven L Goldstein1,2
1Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA.
Nature
|September 6, 2016
まとめ
HIMUマントルの源は,以前はリサイクルされた海殻と考えられていましたが,現在は炭酸塩流体によって変化したペリドートと特定されています. この過程は数十億年にわたって 古代亜大陸の石層マントルで起こりました
科学分野:
- 地化学
- ペトロロジー
- 地球科学
背景:
- マントルの融解と地殻のリサイクルが 地球の化学的分化を促進します
- HIMU (高U/Pb) マントルの末端は,地球のマントルの重要な構成要素である.
- 過去のモデルでは HIMUは 海殻のリサイクルから 生まれていると示唆していましたが 最近の研究では この考えに異議を唱えています
研究 の 目的:
- HIMUマントルの端末の起源を調査する
- HIMUマグマの化学組成に起因するプロセスを解明する.
- HIMU源の多段階の進化を再構築する
主な方法:
- HIMUの溶岩のオリヴィンフェノクリスタスの高精度微量元素分析
- ダイヤモンドの炭酸塩溶融の分析
- 硫黄の同位体のデータを調べる
主要な成果:
- オリビンのフェノクリスタは,HIMUマグマが炭酸塩流体によってメタソマタイズされたペリドートから生じることを示している.
- 微量元素のパターンは,HIMUの溶岩とダイヤモンドの炭酸塩溶融を含有を結びつける.
- 証拠によると,メタソマチズムはコンベクションから隔離された亜大陸の石層マントルで発生した.
結論:
- HIMUの末端は,炭酸塩によってメタソーマ化された亜大陸の石層マントルから生じる.
- この過程はアルカイン-初期プロテロゾイクで発生し,潜水と表面物質が関与した.
- HIMUの源は 地球の歴史の半分以上をカバーする 複雑で多段階の進化を遂げています
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