まとめ
大規模な大陸の洪水ベースルト火山は,過去2億5000万年にわたって11の異なるエピソードで発生しました. これらの火山の出来事は,およそ3200万年の準周期的なサイクルを示し,大量絶滅と一致しています.
科学分野:
- 地質学 地質学 地質学
- ジオクロノロジー (Geochronology) について
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
背景:
- 大陸の洪水ベースルト火山の噴火は,重要な地質学的な出来事を表しています.
- これらの出来事のタイミングと周期性を理解することは,地球科学にとって極めて重要です.
- 以前の年代測定は,バイオストラティグラフィックと古磁気尺度に基づいていました.
研究 の 目的:
- 大規模な大陸の洪水,玄武岩火山の噴火の始まりの年代を定めるため.
- これらの火山のエピソードの周期性を決定するために.
- 火山活動と大量絶滅の間の潜在的な相関を調査する.
主な方法:
- ベースルティック岩石と侵入の公開されたカリウム-アルゴン (K-Ar) とアルゴン-アルゴン (Ar-Ar) の放射測定年代測定を用いた.
- バイオストラティグラフィックと古磁気時間尺度から独立した年代順を確立した.
- 初期日付の誤差を推定するために,放射線年代分布を分析した (約. +/- 4%) となる.
主要な成果:
- 過去2億5000万年の大陸の洪水ベースルト火山の11つの異なるエピソードを特定しました.
- これらのエピソードの準周期的発生を決定し,平均サイクル時間は32 +/- 100万年です.
- 火山の噴火の開始時期は,海洋生物の大量絶滅の推定時期と密接に一致することを観察した.
結論:
- 大陸の洪水ベースルト火山は周期的なパターンを示しています.
- この周期性は,彗星シャワーのような地球外生命体との衝突に関連している可能性がある外部のトリガーを示唆しています.
- 大量絶滅との相関は,大規模な火山活動が地球の生物圏に及ぼす深い影響を強調しています.
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