南アパラチアの変形岩からのミシシッピの化石と,その影響が,後期パレオゾーイク時代の構造進化に及ぼす影響
Science (New York, N.Y.)
|October 29, 1993
まとめ
アラバマ州タラデガのスレートベルトで発見されたミシシッピ族の化石は,変形が以前考えられていたよりも遅かったことを示している. この発見は,南のアパラチア山脈の構造の歴史を再評価することを必要としています.
科学分野:
- 古生物学とストラティグラフィー
- 構造地質学と構造構造学
背景:
- 西部ブルーリッジ帯の一部であるアラバマ州のタラデガ石板帯は,以前は,アカディアのオロジェニー中に変形と変形を経験したと信じられていた.
- 既存の解釈は,これらの地質学的な出来事が初期炭鉱期以前に起こったことを示唆している.
研究 の 目的:
- タラデガの石板帯内の変形と変形のより正確な年齢を確立するために.
- 新しい化石の証拠に基づいて,南端のアパラチア山脈の構造の歴史を再評価する.
主な方法:
- エリン・スレートから化石,特にPeriastron reticulatumの回収と識別.
- 化石を含む岩層の地質学的年齢を決定するためのストラティグラフィック分析.
主要な成果:
- Periastron reticulatum Ungerの化石を修正しました. ベックが回収され,ミシシッピ (Kinderhookian-Tournaisian) 時代をエリンスレートに確立しました.
- この年齢は,タラデガ石板帯の変形と変形が,初期炭鉱期 (アレガニアン期) の後に起こったことを示しています.
結論:
- 新しい化石データは,この地域におけるアカディアのオロジェニスのタイミングに関する以前の解釈と矛盾しています.
- 初期炭鉱期の後の変形および変形現象を考慮して,最も南端のアパラチア山脈の構造進化の改訂された理解が必要である.
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