まとめ
大盆地では地殻の縮小と拡張が顕著になり,改訂された地質的再構築が必要となった. 新しい分析により,少なくとも104-135 kmの縮小と250 kmの拡張が明らかになり,そのプロテロゾーイクからカンブリア初期盆地への理解を再構築しました.
科学分野:
- 地質学 地質学 地質学
- テクトニクス (地質学) とは
- 構造地質学 構造地質学
背景:
- グレート・ベースンは,プロテロゾーイクとパレオゾーイク時代の地質学と地殻の力学を理解するために不可欠です.
- メソゾイクとケノゾイク時代の変形史の以前の再構築は,新しいデータのために改訂する必要があります.
研究 の 目的:
- 大盆地の中期のプロテロゾーイクからカンブリア初期までの岩石のための新しいパリンパスティック再構築を開発するために.
- 正確な地域文脈のために,メソゾーイク-ケノゾーイク地殻の縮小と拡張に関する新しい発見を統合する.
主な方法:
- 東向きの突起と折りたたみによる地殻の縮小に関する地質学的証拠の分析.
- メソゾーイク後期以降の拡張方向と大きさを制限するための古磁気データ.
- 地質学的および古磁気学的不確実性は,緯度による拡張の変動を推定するために使用されました.
主要な成果:
- 全地殻の縮小は104~135キロメートルと推定されている.
- 大盆地では,約250キロメートルの延長が発生しました.
- 原始のプロテロゾイクとカンブリア初期盆地の幅は150~300キロメートルで,より南北方向に傾いている.
結論:
- 改訂された再建は,グレート・ベーシンの地質史のために必要である.
- この地域は,かなりの縮小と拡張を経験し,その古地理学を大幅に変えました.
- 古磁気データはシエラネバダの最小回転をサポートし,延長計算を簡素化しています.
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