マイクロテクタイトと大量絶滅:デボニア期の後半に小惑星が衝突した証拠
Science (New York, N.Y.)
|August 21, 1992
まとめ
研究者らは,ベルギーのフラズニア・ファメニア境界付近で,マイクロテクトイトに似たガラスの球体を発見した. 彼らの特徴は衝突の起源を示唆し,このイベントをデボニア上期の大量絶滅と結びつける可能性があります.
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:
- フラズニアン-ファメンニアン (F/F) 境界は,上デボニアンにおける主要な海洋大量絶滅のイベントをマークしています.
- マイクロテクタイトはしばしば大きな衝撃の出来事と関連付けられています.
研究 の 目的:
- ベルギーのセンゼイルでF/Fの境界付近で発見されたガラス球体の起源と重要性を調査する.
- 地球外の衝突とF/Fの大量絶滅の間の潜在的な関連性を評価する.
主な方法:
- ガラスの球体の形態学的分析.
- 球体組成の地球化学分析.
- 既知のマイクロテクタイトと衝撃構造との比較.
主要な成果:
- Senzeillesで発見されたガラスの球体は,マイクロテクタイトのような形態 (涙滴,ダンベル,複合体) を表しています.
- これらの球体には結晶がなく,小胞が少なく,衝突噴出物と一致する低揮発性物質含有量があります.
- 同様の年齢の候補衝突クレーターが存在する (Siljan Ring,Charlevoix).
結論:
- センゼイル球体の特徴は,衝撃の起源を強く支持しています.
- F/F境界の近くにあるこれらのマイクロテクタイトのような球体の存在は,衝突イベントの証拠を提供します.
- この衝突の出来事は,上デボニアの大量絶滅の潜在的な原因である.
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