太平洋北東部のマザマ・アッシュ
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まとめ
海洋沈殿物の分析により,マザマ山の灰と一致する火山ガラスが発見され,沈殿物の分散を追跡し,深海のプロセスを理解するのに役立ちます.
科学分野:
- 海洋地質学 海洋地質学
- 火山学 火山学とは
- 堆積物学 堆積物学 堆積物学 堆積物学 堆積物学
背景:
- 火山灰の層は,海洋沈殿物の時間戦略的マーカーとして機能する.
- 灰の散布を理解することは,過去の地質学的な出来事と海洋学的なプロセスを再構築するのに役立ちます.
研究 の 目的:
- 海洋堆積物で見つかった火山ガラスを,大陸の灰堆積物と関連付けるため.
- 火山灰を,氷河後の堆積物散布経路のトレーサーとして利用する.
- 灰堆積物を用いて海洋沈殿過程を評価する.
主な方法:
- 海洋堆積物核のストラティグラフィック分析.
- 火山ガラスの断片の屈折指数測定. 火山ガラスの断片の屈折指数測定. 火山ガラスの断片の屈折指数測定. 火山ガラスの断片の屈折指数測定. 火山ガラスの断片の屈折指数測定. 火山ガラスの断片の屈折指数測定. 火山ガラスの断片の屈折指数測定.
- 灰を含む堆積層の放射性炭素年代測定.
主要な成果:
- オレゴン州とワシントン州沖の海洋堆積物にある火山ガラスは,マザマ山の灰とうまく相関していた.
- この相関は,層図の位置,屈折率,放射性炭素年代測定によって確認された.
- アビサルの灰の堆積は,流動堆積から生じたと特定されました.
結論:
- 火山ガラスは,海洋と大陸の地質記録を相関させるための信頼できるマーカーを提供します.
- トルビディティ電流で堆積した灰は,深淵の環境における堆積物の分散を追跡するための貴重なツールです.
- この研究は,海洋の堆積物プロセスと古海洋学の理解を深める.
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