まとめ
トリウム-230 (Th230)) とプロタクトニウム-231 (Pa231) の活性比は,ほとんどのマンガンのノードルで,海洋生産比を下回っています. これは,これらの放射性元素の海底堆積物における異なる蓄積率を示唆している.
科学分野:
- 地質化学 地質化学
- 海洋地質学 海洋地質学
- 放射化学は放射化学である.
背景:
- トリウム-230 (Th230)) とプロタクトニウム-231 (Pa231) は,異なる半減期を持つ自然に存在する放射性同位体である.
- これらの同位体は水柱で生成され,海洋沈殿物に組み込まれます.
- オーチジェニックな海洋堆積物におけるTh230)/Pa231) の活動比は,蓄積プロセスに関する洞察を提供することができる.
研究 の 目的:
- マンガンのノードルにおけるTh(230)/Pa(231) アクティビティ比を調べる.
- 測定された比率と海洋における理論的な生産比率を比較する.
- manganese-iron oxide depositsにおける微分ヌクリドの蓄積への影響を理解するために.
主な方法:
- マンガンの結節のサンプルを分析する.
- トリウム-230とプロタクトニウム-231の活性比を放射線測定技術を用いて測定する.
主要な成果:
- 分析された11個のマンガンのノードルのうち7つのTh230) / Pa231) アクティビティ比は10.8.8未満でした.
- 海洋におけるTh(230)/Pa(231) 活動の理論的生産比は10.8.8である.
- これは,分析されたサンプルの予想比率からの偏差を示しています.
結論:
- 観測されたより低いTh230) / Pa231) 活性比は,これらの核酸の異なる蓄積を示唆しています.
- オーチジェニックのマンガネス・鉄酸化物埋蔵は,Th230とPa231の海洋生産比率を保たれていない.
- これは,ノードル形成の過程で,一つのヌクリドを他のヌクリドよりも優先して組み込むか,除去することを意味する.
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