まとめ
クレタ紀末期の大量絶滅は選択的であり,瞬間的ではなかった. 証拠によると,地球ベースのマントルの乱れは,これらの絶滅のイベントの地球外からの衝撃よりも妥当性があることを示唆しています.
科学分野:
- パレオントロジー・パレオントロジー
- 地質学 地質学 地質学
- 地球科学 地球科学 地球科学
背景:
- クレタ紀末期は,大規模な大量絶滅を経験した.
- アルバレス仮説は,一つの小惑星の衝突が原因であると提案した.
- この仮説は,絶滅の選択的であり,瞬間的ではない性質によって異議を唱える.
研究 の 目的:
- オリジナル・アルバレス仮説の妥当性を評価する.
- クレータ紀末期の大量絶滅の代替モデルを調査する.
- これらの絶滅の出来事の地質学的および環境的トリガーを決定する.
主な方法:
- ストラティグラフィック記録から得られた物理的,化学的証拠の分析.
- 地外衝突モデル (小惑星,彗星) と地上のモデルを比較する.
- 絶滅イベントのタイミングと選択性の評価.
主要な成果:
- クレタ紀末期の大量絶滅は,地質学的に瞬間的でもなく,すべての生命に均等に影響を及ぼさなかった.
- 単一の小惑星の衝突シナリオは,観測された絶滅パターンと矛盾しています.
- 彗星シャワーを含む改造された地球外モデルの可能性は,内部で駆動された地上のイベントよりも低いです.
結論:
- オリジナルのアルバレス仮説は,大幅な修正または拒絶を必要とします.
- 地上の原因,特にマントルの乱れは,観測された絶滅パターンのより妥当な説明を提供します.
- 地球の地質学的過程に関するさらなる研究は,過去の大量絶滅を理解するために不可欠です.
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