カリフォルニア州シエラネバダの南下にある大陸弧の根の活発な沈殿
George Zandt1, Hersh Gilbert, Thomas J Owens
1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA. zandt@geo.arizona.edu
Nature
|September 3, 2004
まとめ
シエラネバダ山脈の密集した根は,マントルの滴水によって除去され,地殻の厚みや沈みを引き起こしています. 粘着性結合によって引き起こされるこのプロセスは,カリフォルニアの山脈を再構成します.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- テクトニクス (地質学) とは
- ジオダイナミクスは地力学です.
背景:
- 地殻とマントルの相互作用を理解することは,山脈の進化を理解するために極めて重要です.
- 南部のシエラネバダ山脈は,これらのプロセスを研究するためのユニークな自然実験室を提供します.
研究 の 目的:
- シエラネバダ山脈のバトロリート根の採掘を調査する.
- 地殻とマントルの相互作用とその表面効果の地震画像を分析する.
主な方法:
- 地震データの分析により,地下構造やプロセスをイメージする.
- 地質学的データを解釈して地殻とマントルの動態を理解する.
主要な成果:
- 地震データは,レイリー・テイラー不安定によって1000万~300万年前に始まったシエラネバダの密集した根の除去を明らかにしています.
- ほぼ水平の切断ゾーンは,超マフィア系を切り離し,粘着性の牽引は,西側側層の地殻を7km厚くした.
- V形の地殻の円がマントルのドリップに引っ張られ,地震画像でモホの姿を消し,表面沈沈を誘発する.
結論:
- シエラネバダ山脈のバトリーチ根の除去は,活発な地力学的プロセスです.
- 地殻とマントルの間の粘着性結合は,この地域における現在の地表沈没の主な要因である.
- 地震画像は,大陸の山脈のダイナミックな進化について重要な洞察を提供します.
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