コンドライト:初期ストロンチウム-87/ストロンチウム-86の比率と太陽系の初期史
Science (New York, N.Y.)
|October 19, 1973
まとめ
この研究では,アレンデ隕石のストロンチウムイソトープを分析し,初期にストロンチウム-87/ストロンチウム-86の比率が低いことを明らかにしました. この発見は,この特定の隕石成分のための初期の太陽系形成を示唆しています.
科学分野:
- 宇宙化学 (コスモケミストリー)
- 惑星科学 惑星科学
- イソトープ地球化学 イソトープ地球化学
背景:
- 炭酸性コンドライトは,初期の太陽系プロセスに関する重要な洞察を提供します.
- ストロンチウム同位体比 (87Sr/86Sr) は,惑星形成の年代測定と理解のための重要なトレーサーである.
研究 の 目的:
- アレンデ隕石内の特定の含有物の初期ストロンチウム同位体組成を決定する.
- このインクルージョンの形成タイミングを他の隕石タイプと比較するために.
主な方法:
- ストロンチウムイソトープを用いた放射線年代測定.
- アレンデ隕石からの,ナトリウムが少ない,カルシウムが豊富なインクルージョンの87Sr/86Sr比の分析.
主要な成果:
- アレンデの含有は,0.69880の初期87Sr/86Sr比率を示し,これは隕石で記録された最低値の1つです.
- 普通のコンドライトは,より高い87Sr/86Sr比を示し,後期形成または同位体均衡を示している.
結論:
- 低い87Sr/86Sr比は,太陽系の始まりの近く,このアレンデ含有体の初期の形成イベントを示しています.
- 同位体差異は,異なる隕石のクラス間の異なる形成時間軸を強調しています.
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