コスタリカとニカラグアの下のマントル・ケイジの弧平行流は,コスタリカとニカラグアの下にある
Kaj Hoernle1, David L Abt, Karen M Fischer
1SFB 574, University of Kiel, Wischhofstrasse 1-3, Kiel 24148, Germany. khoernle@ifm-geomar.de
Nature
|January 29, 2008
まとめ
中央アメリカの下の溝-並列マントルの流れは,従来の沈下ゾーンモデルに挑戦しています. 同位体地化学は,ココスプレートからの火山の起源を明らかにし,プレート構造の速度と比較できる北西方向の大幅なマントルの動きを示しています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- 地質化学 地質化学
- テクトニクス (地質学) とは
背景:
- マントルのの流れを理解することは,プレート脱水,融解,および弧火山活動を含む潜水地帯のダイナミクスにとって非常に重要です.
- 古典的なモデルは,沈殿板によって駆動される溝の正常なマントルの流れを予測する.
研究 の 目的:
- コスタリカとニカラグアの下のマントル・ケイン・フローの幾何学を調査する.
- 火山岩の地化学的サインとマントルの動態を調和させるため.
主な方法:
- 火山岩における同位体地化学の分析.
- 地震速度のアニソトロピー測定. 地震速度のアニソトロピー測定.
- ジオクロノロジカルと輸送距離の推定.
主要な成果:
- コスタリカとニカラグアの下には,溝とマントルの平行流の証拠がある.
- 火山岩は,ココスプレートに潜るガラパゴス熱帯の海底山々から生じた同位体シグネチャーを示しています.
- 北西向きのマントルの流動率 (63~190mm/年) は,ココスプレート運動 (~85mm/年) と比較できます.
結論:
- この発見は,の通常の流れの古典的なモデルと矛盾しています.
- トレンチ・パラレル・フローは,潜水域の熱的・化学的構造と溶融生成のモデルに組み込まれなければならない.
- この流れは,アーチ火山活動と関連する気候影響に影響を与えます.
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