原始的なコンドライトからダイヤモンドの複数の源があるという証拠があります
まとめ
隕石の細粒子のダイヤモンドは,宿主隕石のタイプに関連した炭素と窒素同位体の変動を示しています. これらの本質的な差異は,初期の太陽星雲の異質な分布を示唆しています.
科学分野:
- 宇宙化学 (コスモケミストリー)
- 惑星科学は惑星科学である.
- マテリアルサイエンス 材料科学
背景:
- 細粒子のダイヤモンドは,原始的な隕石に含まれる星周塵が豊富にあるものです.
- その元素と同位体組成は,宿主隕石の影響を受けます.
- 以前の研究では,ダイヤモンドの性質の変動が認められたが,明確な説明は得られなかった.
研究 の 目的:
- 異なるタイプの隕石から採取された細粒子のダイヤモンドの元素および同位体特性を調査する.
- 窒素含量と炭素同位体組成の変動の原因を特定する.
- 初期の太陽星雲におけるこれらのダイヤモンドの形成と分布を理解するために.
主な方法:
- 普通のコンドライトとCM2型コンドライトから細粒子のダイヤモンドを分離する.
- 炭素と窒素の同位体組成物の分析.
- 炭素と窒素の比率の進化を研究するための燃焼実験.
主要な成果:
- 炭素同位体組成は,ミリリットルあたり -32から -38の範囲であった.
- 隕石の種類によって窒素の豊富さは (0.2~0.9重量%) 大きく変化した.
- 窒素の差異の主な原因として,変形脱ガス化は排除された.
結論:
- 観測されたダイヤモンドの組成の変動は,その形成から受け継がれている可能性が高い.
- ダイヤモンドは凝縮過程で太陽の星雲の中で異質に分布していた.
- ダイヤモンドの内部に隠された窒素媒体が,貢献要因として排除できない.
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