コンチネンタル・マージン・リトスフィアの潜水駆動によるリサイクル
A Levander1, M J Bezada2, F Niu3
1Earth Science Department, Rice University, Houston, Texas 77005-1892, USA.
Nature
|November 14, 2014
まとめ
海洋プレートによる沈殿は,大陸の石層を隣接する縁から引きずり込み,除去することができます. プレート構造によって引き起こされるこのプロセスは,石層を薄くし,大陸の変形に影響を与えます.
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:
- 大陸の石層のリサイクルは,海洋の石層のリサイクルよりも複雑で理解が少ない.
- デラミネーションとコンベクティブダウンウェリングは,石層マントルの除去における重要なプロセスです.
- 隣接する大陸の石層除去における海洋プレート沈殿の役割が調査されています.
研究 の 目的:
- 海洋プレート沈殿と大陸石層の除去との関連を調査する.
- サブドクションゾーンに隣接する大陸の石層の薄まりを説明するために.
- 海洋と大陸の構造のジオダイナミックモデルを調和させるため.
主な方法:
- 密度の高いブロードバンドの地震実験によるテレシーミックボディウェーブイメージング.
- 沈殿した大西洋とアルボランのスラブの分析.
- リトスフィアのマントルの厚さを決定するレイリー波分析.
主要な成果:
- 大陸の縁の下で見つかった沈下したスラブに関連した異常な速度のマントル容積.
- 大陸の縁の下で見られた,かなり薄い石層マントル.
- 薄いリトスフィアは,オロゲンから内陸まで,クレートン核に向かって広がっています.
結論:
- 海洋プレートによる沈殿は,大陸の熱境界層の底を引きずり込み,除去する可能性があります.
- このプロセスは,表面構造を駆動し,石層-アステノスフィアの境界で地形を形成します.
- 二次的なダウンウェリングと,石層マントルの潜在的デラミネーションにつながります.
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