まとめ
近くのボリドの衝突により,クレタセウス時代と第3期の境界でマイクロテクタイトとショックを受けたクォーツが生まれた. その後の津波がこれらの堆積物を再処理し,混合化石で複雑なマーカーベッドを作成しました.
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
- インパクトクラテリング (インパクトクラテリング)
背景:
- クレータ紀-三次紀 (K-T) の境界線は,重大な大量絶滅の出来事を示しています.
- この境界のマーカーベッドは,K-Tイベントの重要な証拠を提供します.
- ハイチ南部にあるベロック・フォーメーションは,ユニークなK-T境界線を提示しています.
研究 の 目的:
- ベロック・フォーメーションのK-T境界標識床の形成と堆積の歴史を調査する.
- マーカーベッドの組成と構造を分析するために.
- 潜在的なボリド衝突後のイベントのシーケンスを理解するために.
主な方法:
- マーカーベッドのフィールド観測.
- マイクロテクタイトとショッククォーツのペトログラフィック分析.
- プランクトンフォラミニフェラの分布分析.
主要な成果:
- 標識床の基礎部分には,多量のマイクロテクタイトとショッククォーツが含まれており,ボリド衝突の兆候です.
- 上の部分は,合体されたマイクロテクタイトレンズを持つマールで構成されており,再加工が示唆されています.
- 証拠は,2段階のイベントを示唆しています:最初の衝撃堆積と津波によって引き起こされた再処理が続く.
結論:
- ベロック・フォーメーションの白紀・三次紀の境界にあるマーカーベッドは,複雑な一連の出来事の結果である.
- 近くのボリドの衝突により,地外物質で床の形成が開始されました.
- その後の大きな破壊的な出来事,おそらく津波は,最初の堆積物を再処理し,混合微生物化石の組み立てにつながった.
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