まとめ
新しい分析技術により,稀土鉱物のルテチウム176/ハフニウム176年代測定が可能になりました. この研究では,ルテシウム-176の半減期を精製し,地質学的および物理的な測定を確認しました.
科学分野:
- 地質化学 地質化学
- ラジオメトリック・デッティング
- イソトープ地球化学 イソトープ地球化学
背景:
- ルテシウム176/ハフニウム176 (176Lu/176Hf) の同位体系は,地質年代測定の強力なツールです.
- 以前の制限により,この方法の適用は,希土元素 (REE) に富んだ鉱物 (グラムの大きさ) に対して困難であった.
研究 の 目的:
- ルテシウム (Lu) とハフニウム (Hf) の同位体の精密な測定のための高度な分析技術を開発し,適用する.
- 176Lu/176Hfジオクロノメーターを,希土を含むより大きな鉱物サンプルに適用できるようにするためです.
- 176Lu.の半減期を地質学的に再定義する.
主な方法:
- マイクログラムレベルの Lu と Hf.のための専門的な分析および同位体稀释技術の開発.
- REEを含む鉱物のグラム量に対するこれらの方法の適用.
- 176Lu半減期の地質学的再決定.
主要な成果:
- 176Lu/176Hfメソッドをグラムサイズの鉱物サンプルに成功裏に適用しました.
- マイクログラムレベルでのLuおよびHf同位体の正確な測定.
- 176Lu の再決定された地質学的半減期は 3.3 +/- 0.5 x 10 ((10) 年です.
結論:
- 開発された分析技術は,176Lu/176Hf年代測定法の適用性を大幅に高めています.
- 176Luの新しい半減期値は,最近の物理的な測定と一致しており,地球年代測定の精度を高めています.
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