まとめ
ダイヤモンドと炭酸は,特定の反応により,マントルのエコロギットで共存することができます. この発見は,地質学的形成とダイヤモンドを含む岩の保存を説明します.
科学分野:
- 地質化学 地質化学
- ミネラロジーは,鉱物学です.
- ペトロロジー・ペトロロジーとは
背景:
- ダイヤモンドと炭酸塩は,地球のマントルの重要な成分です.
- 彼らの共存を理解することは,マントルのプロセスへの洞察を提供します.
研究 の 目的:
- エコロギットにおけるダイヤモンドと炭酸塩の共存を制御する反応を定義する.
- エクロギットとペリドータイトにおけるダイヤモンドの安定性について,酸素の揮発性の条件を比較する.
主な方法:
- 反応の熱力学分析:ドロマイト + 2 コエサイト <=> ディオプサイド + 2 ダイヤモンド + 2O(2).
- 酸素流動性 (fO2) 条件の比較.
主要な成果:
- ドロマイト + 2 コエサイト <=> ディオプサイド + 2 ダイヤモンド + 2O(2) の反応は,エクロギットにおけるダイヤモンド-炭酸塩の共存を定義する.
- エクロジットのダイアモンドの安定性は,ペリドータイトよりも約1log単位高い酸素逃逸度で発生します.
- この違いにより,ダイヤモンドを含有するエクロギットと炭酸を含有するペリドチートが共存できる.
結論:
- 異なった酸素流動性の条件は,エクロジットとペリドチットの観測された地質学的な関連性を説明します.
- これは,ダイヤモンドを含有するガーネット・ピロクセニート (モロッコのベニ・ブーセラ山脈) と交差した無炭素のペリドータイトを説明できる.
- また,ダイアモンドを含有するエコロギット系キセノリトが,ペリドート系 (ロバート・ビクター・キンバーライト) よりも優遇的に保存されていることも説明できる.
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