海洋変形断層に沿った重力異常の拡散率依存度
Patricia M Gregg1, Jian Lin, Mark D Behn
1Department of Geology and Geophysics, Massachusetts Institute of Technology/Woods Hole Oceanographic Institution Joint Program, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
Nature
|July 13, 2007
まとめ
中洋のの変形断層は,拡散速度に関連した重力異常を示している. より速い拡散率は負重力異常と相関しており,これらの断層の近くに地殻の厚みと3Dマグマの蓄積が増加することを示唆しています.
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
- 海洋学 海洋学とは
背景:
- 中洋のの形態学と地殻の増殖は,広がり速度によって影響を受けます.
- ゆっくり広がる山脊は,マントルの集中した上流によるオフセットで地殻の薄めを示している.
- 急速に広がるは,マントルの上流が均一で,地殻の厚さの変動が小さい.
研究 の 目的:
- 海洋変形断層における拡散速度と重力の異常との関係を調査する.
- 変形断層における地下質量分布と地質学的過程を理解する.
主な方法:
- 残存マントルのブーガー重力の異常を体系的に研究する.
- 19つの海洋変形断層の分析.
- 重力シグネチャと広がり率の相関.
主要な成果:
- ゆっくりと滑る変形断層は,重力の正の異常がある.
- 中間変形断層と高速変形断層は,負の重力異常を示している.
- 負の異常は地形的な高値と相関しており,地殻の厚くなっていることを示唆しています.
結論:
- 質量赤字は,中間と高速滑り変形断層で存在します.
- 地殻の加厚は,負重力異常に大きく寄与する要因である.
- 三次元マグマの蓄積は,急速に広がる変形断層の近くに発生する可能性があります.
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