クレタケイア期における海洋無酸素現象の潜在的な原因として,熱ハリン層分化の増加
J Erbacher1, B T Huber, R D Norris
1Bundesanstalt für Geowissenschaften und Rohstoffe, Referat Meeresgeologie, Hannover, Germany. erbacher@bgr.de
Nature
|February 24, 2001
まとめ
OAE 1bのようなクレタ紀中期の海洋無酸素現象は,熱ハリン層分化の増加によって引き起こされた. これにより,気温が上昇し,流出,地下水の形成が減り,炭素の埋葬が大きくなりました.
科学分野:
- パレオセアノグラフィーとは
- 地質化学 地質化学
- 気候科学 気候科学
背景:
- 海洋無酸素現象 (OAEs) は,高炭素埋葬,CO2の減少,そして絶滅によって特徴付けられます.
- OAEは通常,高表面生産性と有機に富んだブラックシェール形成と関連しています.
- いくつかのOAEのトリガーは不明のままです.
研究 の 目的:
- クレタ紀中期における海洋無酸素現象 (OAE 1b) の原因を調査する.
- 安定同位体データを分析して,古海洋学的条件を理解する.
- OAE 1b.中に炭素埋葬の増加につながる要因を決定する.
主な方法:
- 地質学的記録の安定同位体分析. 地質学的記録の安定同位体分析.
- パレオセアノグラフィーの再構築.
- クレタ紀中期の堆積物の地化学分析.
主要な成果:
- 安定同位体データは,1億1,200万年前,熱ハリン分層化の増加を示しています.
- OAE 1bは,地表温度上昇と流出量の増加と相関しています.
- 証拠によると,テティス川と北大西洋の地下水形成が減少し,炭素埋蔵量が増加していることが示唆されています.
結論:
- 熱ハリン分層の増大が,OAE 1b.の確率的な原因であった.
- OAE 1bは,北大西洋とテティスに影響を与える広範なプロセスを含んでいた.
- このイベントは,四季期のサプロペルよりも大きな領域でより多くの炭素を閉じ込めました.
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