競合する構造とジブラルタル弧の侵食によって規制されたメッセンニア海塩度危機
D Garcia-Castellanos1, A Villaseñor
1Instituto de Ciencias de la Tierra Jaume Almera, CSIC, Solé i Sabarís s/n, 08028 Barcelona, Spain. danielgc@ictja.csic.es
Nature
|December 16, 2011
まとめ
メッシニアの塩分危機は,地中海への大西洋流入の減少によって引き起こされた. 数値モデリングは,海路の侵食が対抗した構造的上昇を明らかにし,浅い接続を維持し,塩の降水を説明しています.
科学分野:
- 地球科学 地球科学 地球科学
- 海洋学 海洋学とは
- 地質学 地質学 地質学
背景:
- メッシニア塩分危機 (5.96~5.33万年前) は,大西洋からの地中海流入が減少し,大量に塩分が降ったり,海面が下がったりした.
- 以前の説明は,構造的上昇と世界の海面の変化に焦点を当てていたが,広範囲の塩分堆積に必要な長期にわたる浅い接続と時間スケールを調和させるのに苦労した.
研究 の 目的:
- メッセンニア海塩度危機の間,大西洋と地中海の間の浅いつながりを維持する海路侵食の役割を調査する.
- 地質構造の上昇と海面の変化の時間スケールを,地中海と大西洋の接続の持続時間と調和させる.
主な方法:
- 海路のダイナミクスをシミュレートするための数値モデリング,異なる構造的および浸食的条件下で.
- 地質学的証拠と地力学モデルによるモデルによる侵食と上昇率の比較.
主要な成果:
- 大西洋の流入によって引き起こされる海路の侵食は,地質学的な上昇を相殺し,浅い接続を維持する可能性があります.
- 必要な侵食と上昇率は,ジブラルタル・アークと地力学モデルからの地質学データと一致しています.
- 適度な上昇と侵食の間のバランスが,地中海の初期の海平面の引き下げと周期的な塩の降水を説明しています.
結論:
- 海路の浸食は,メッセンニア海塩度危機の間,浅い大西洋-地中海接続を維持するための重要なメカニズムです.
- 浮揚と侵食の相互作用は,初期の塩鉱の周期性について新しい説明を提供します.
- これは,メッセンニア海塩度危機のタイミングとメカニズムに関する以前の仮定に異議を唱える.
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