(Mg,Fe) SiO3ペロブスキットの不均衡は,地球の深い下層マントルの深い部分にある
Li Zhang1, Yue Meng2, Wenge Yang3
1Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, China. Geophysical Laboratory, Carnegie Institution of Washington (CIW), Washington, DC 20015, USA. zhangli@hpstar.ac.cn.
Science (New York, N.Y.)
|May 24, 2014
まとめ
地球の下層マントルのペロブスキートは不安定で,高圧で鉄を失う. これは,新しい主要な鉱物相が地球の奥深くに存在し,地震の解釈に影響を与えていることを示唆しています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- ミネラル物理学 ミネラル物理学
- 地球科学 地球科学 地球科学
背景:
- 下層マントルのモデルは,フェロマグネシアンシリケートペロブスキートの安定性を想定しています.
- 以前のモデルは,下層マントルのペロブスキートに10モルパーセントの鉄を組み込みました.
研究 の 目的:
- 下層マントルの条件下におけるフェロマグネシアンシリケートペロブスキートの安定性を調査する.
- 極端な圧力と温度下でのペロブスキート内の鉄の振る舞いを決定する.
主な方法:
- 実験では,レーザーで加熱されたダイヤモンドアンビルセルを使用した.
- 下マントルのシミュレートされた圧力 (95-101 GPa) と温度 (2200-2400 K).
主要な成果:
- フェロマグネシウムシリケートペロブスキートは,研究された条件下で不安定です.
- ペロブスキットは不釣り合いになり,鉄を失い,Feが豊富な六角形とFeが少ないMgSiO3のペロブスキットを形成します.
結論:
- 下層マントルの構成に関する既存のモデルは,改訂が必要である.
- 下層マントルは,これまで未確認の主要な鉱物相を宿しているかもしれない.
- この発見は,地球深層の地震異常を解釈する上で意味を持つ.
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