パプアニューギニアのウッドラーク・リフトにある活発な変形核複合体のマントル補償
Geoffrey A Abers1, Aaron Ferris, Mitchell Craig
1Department of Earth Sciences, Boston University, Boston, Massachusetts 02215, USA. abers@bu.edu
Nature
|August 23, 2002
まとめ
メタモルフィック・コア・コンプレックスは,重要な地殻の拡張を容認する. 地震データは,地殻の流れだけでなく,マントルの拡張が,Woodlark裂け目のこれらの高層構造を支えていることを示しています.
科学分野:
- テクトニクス (地質学) とは
- 地質物理学 地質物理学とは地質物理学です.
- 地質学 地質学 地質学
背景:
- メタモルフィック・コア・コンプレックスは,地殻の拡張の間に形成され,地殻の中間の岩石を掘り起こします.
- 上層地殻の除去にもかかわらず,それらの高い高さと同静的均衡は議論の余地があります.
- 既存のモデルでは,低地殻の流れやマグマ底層がそれらの上昇を支えていると仮定することが多い.
研究 の 目的:
- 変形核複合体の下の地殻とマントルの反応を調査する.
- これらの拡張した地殻構造の地形的な上昇を支えるメカニズムを理解するために.
主な方法:
- 地震観測は,地殻と上層マントルの構造をイメージするために使用されました.
- マントルの性質を推測するために,地殻の薄めと地震速度の分析.
主要な成果:
- 表面延伸が大きい領域の下の全地殻の薄めが観察されました.
- コア・コンプレックスの下にある異常な低密度のマントル岩を特定し,低地震速度で示した.
- Myr(-1) の 5-10 km のアクティブ発掘率が測定されました.
結論:
- メタモルフィック・コア・コンプレックス開発には,マントルの拡張が大きく含まれます.
- 観測された地殻の薄れは,地殻の流れだけでなく,マントルのプロセスによって補償されます.
- これらの環境における拡張性アコマデーションは,殻とマントルの組み合わせによる現象である.
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