ルビジアム-ストロンチウム,ウラン,ソリウム-鉛による月の物質の年代測定
Science (New York, N.Y.)
|January 30, 1970
まとめ
この研究では,マイクロガブロのルビジウムとストロンチウムを測定し,34億年と45億年の年齢を測定しました. 鉛の同位体分析は,高度に放射性な表面物質を示唆し,47億年前の閉じたシステムを示唆しています.
科学分野:
- 地質化学 地質化学
- 同位体地質学とは,同位体地質学である.
- ラジオメトリック・デッティング
背景:
- マイクログラブロ岩石のサンプルを分析し,元素と同位素の組成を調べました.
- 同様の地質学的形成に関する以前の研究は,現在の調査のための文脈を提供しました.
研究 の 目的:
- ルビジアム-ストロンチウムおよび鉛-鉛同位体システムを用いてマイクロガブロサンプルの年齢を決定する.
- 表面材料における鉛の同位体の進化を調査する.
主な方法:
- ルビジアムとストロンチウムの濃度,および岩石全体および密度分数の同位体組成物の測定.
- 密度分数からアイソクロン年齢の計算.
- 鉛のイソトープの分析,207Pb/206Pbの比率を含む細かい表面材料の鉛イソトープの分析.
主要な成果:
- 2つのマイクロガブロ試料は,34億年および45億年のアイソクロン年代を示し,低放射性ストロンチウム濃縮による不確実性があります.
- 細かい表面材料からの鉛は,高度に放射性であることが判明しました.
- 207Pb/206Pb比率を用いて,4.75億年の年齢を計算した.
- ウラン,トリウム,鉛の同位体濃度は,47億年前の閉じたシステムと一致しています.
結論:
- マイクロガブロのサンプルは,異なる年齢の範囲を持つ古代の地質学的構造を表しています.
- 表面材料は,特定のウランと鉛,トリウムと鉛の比率を持つ長期閉鎖システムの特徴を示しています.
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