南大西洋の三重交差点の死と変容
1M. Ligi, G. Bortoluzzi, G. Carrara, P. Fabretti, D. Penitenti, Istituto Geologia Marina, CNR, via P. Gobetti 101, Bologna, Italy. E. Bonatti, Istituto Geologia Marina, CNR, via P. Gobetti 101, Bologna, Italy, and Lamont Doherty Earth Observatory of Columbia University, Palisades, NY 10964-8000, USA. D. Gilod, Moscow State University, Moscow, Russia. A. A. Peyve, S. Skolotnev, N. Turko, Geology Institute, Russian Academy of Sciences, Moscow, Russia.
Science (New York, N.Y.)
|April 11, 1997
まとめ
サウスウエスト・インディアン・リッジ (SWIR) が中大西洋リッジ (MAR) に向かって広がるため,南大西洋で新しい三重交差点が形成されています. この地質学的な出来事は,次の100万年以内にプレート境界を再構成し,プレートサイズを変更します.
科学分野:
- ジオダイナミクスは地力学です.
- プレート・テクトニクス (プレート・テクトニクス)
- 地質物理研究に関する研究
背景:
- 南大西洋は,南極,南米,アフリカのプレートの収束を伴う複雑な地形構造を宿している.
- 現在,ブーヴェット島近くには,リッジ・リッジ・リッジ (RRR) トリプルジャンクションが存在し,ミッド・アトランティック・リッジ (MAR),サウスウエスト・インディアン・リッジ (SWIR),アメリカ南極山脈を含む.
研究 の 目的:
- 南大西洋の三重交差点の進行中の進化を調査する.
- 新たに形成されたマグマパルスの地域プレート動力学への影響を分析する.
主な方法:
- プレート相互作用を理解するために地球物理学的データの分析.
- 将来の構造変化を予測するための地質モデリング.
主要な成果:
- スピース・リッジ (Spiess Ridge) と呼ばれるSWIRの一部は,年間4〜5cmの速度で MARに向かって活発に増殖しています.
- この伝播は,既存のRRR三重交差点を破壊しています.
- 新しい三重交差点が,現在の三重交差点から北に約70kmで形成されると予測されています.
結論:
- 進行中のマグマ活動と山脊の伝播は,ダイナミックで進化する構造環境を示しています.
- アメリカン・アンタークティック・リッジは,MARの一部を占領すると予想されている.
- 南極板は,これらの構造的調整により大きくなると予測されています.
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