陸上の材料におけるカルシウム-41濃度:プレイストセンのサンプル年代測定の見通し
Science (New York, N.Y.)
|May 8, 1987
まとめ
カルシウム-41 (Ca-41) は,100万年までの地質サンプルを放射測定法で年代測定するのに有望である. 研究者は,骨と石灰岩のCa-41濃度を測定し,プレイストセンの化石と地球物理学の研究の年代測定の可能性を検証しました.
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
- 核科学は,核科学である.
背景:
- カルシウム-41 (Ca-41) は,放射性年代測定における潜在的な応用を持つ宇宙生成同位体です.
- 以前の研究では,105〜106年の範囲内の地質学的サンプルを年代付けするためにCa-41が示唆されていた.
- 陸上のサンプルのCa-41濃度の決定は,年代測定ツールとしてその使用を検証するために重要です.
研究 の 目的:
- 天然の陸上のサンプルのコスモゲンカルシウム-41の濃度を測定する.
- 地質学的材料の放射線年代測定のためにカルシウム-41を使用する可能性を評価する.
- カルシウム-41測定の地球物理学的応用を探求する.
主な方法:
- 高感度加速器質量スペクトロメトリー (AMS) がCa-41.1の正確な測定に使用されました.
- 検知感度を高めるために,同位体分離器を使用してカルシウム-41の予備濃縮を行った.
- 測定は,当時の牛の骨と石灰岩堆積のサンプルで行われました.
主要な成果:
- 自然サンプルにおけるカルシウム-41の濃度が決定されました.
- 計測されたカルシウム-41とカルシウム総量の比率は2x10^-14から3x10^-15.5の範囲であった.
- これらの濃度は,年代測定アプリケーションの検出範囲内です.
結論:
- カルシウム-41は,高度なAMS技術を使用して,陸上のサンプルで定量化することができます.
- この発見は,Ca-41が,中期および後期プレイストセンの時代の新しい放射線年代測定ツールとしての可能性を裏付けている.
- 将来の研究は,様々な地質学的年代測定の文脈でCa-41の有用性を調査することができます.
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