まとめ
トライアス紀の終わりに複数の衝突が発生し,イタリアのシェール岩床で見つかったショックを受けたクォーツ粒子がそれを証明しています. これらの影響は,レタビキュラ (Rhaetavicula) 種の絶滅と一致しています.
科学分野:
- 地質学 地質学 地質学
- パレオントロジー・パレオントロジー
- 惑星科学は惑星科学である.
背景:
- トライアス紀末期の絶滅イベントは,大規模な大量絶滅です.
- この絶滅の引き金を理解することは,古気候と古環境の再構築にとって極めて重要です.
研究 の 目的:
- トライアス紀・ジュラ紀の境界で起こりうる衝突を調査する.
- イタリアの地質学的な形成におけるショッククォーツを分析するために.
主な方法:
- クォーツの粒子を顕微鏡で平面形変形の特徴を調べる.
- 北アペニネスのシェール床のストラティグラフィック分析.
- ショックを受けたクォーツのペトログラフィック分析.
主要な成果:
- 衝撃により変形したクォーツ粒子は,シェール層の3つの異なる層で特定されました.
- クォーツ粒子の5-10%で観測された平面的変形特徴.
- 衝撃を受けたクォーツの層の平面図的位置は,ラエタビキュラ (Rhaetavicula) のファウナ終点と相関しています.
結論:
- 証拠によると,トライアス紀の終わりに,少なくとも3つの間隔が近い衝突イベントがあったことが示唆されています.
- これらの影響は,トライアス紀・ジュラ紀の境界における環境変化に寄与した可能性がある.
- 地球外生命体の起源と衝突の正確なタイミングを確認するためにさらなる研究が必要でした.
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