カリフォルニア州南部の裂け目地帯の下の石層薄化
Vedran Lekic1, Scott W French, Karen M Fischer
1Department of Geological Sciences, Brown University, Providence, RI 02912, USA. vedran_lekic@brown.edu
まとめ
構造板の裂け方は,大陸と海洋の進化を引き起こします. この研究では,リフトゾーンにおける石層の薄れが明らかになり,単純な切断ではなく,効率的なストレスの局所化と対称的な拡張を示しています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- テクトニクス (地質学) とは
- 地球科学 地球科学 地球科学
背景:
- 大陸と海の進化は,プレート分裂によって引き起こされる.
- リフト形成中の石層変形を理解することは極めて重要ですが,未だに十分に理解されていません.
研究 の 目的:
- リトスフィアのリフト形成中の変形過程を調査する.
- リトスフィアの薄まりを抑制し,裂け目地帯におけるストレスの局所化を制限する.
主な方法:
- 南カリフォルニアのリフトゾーンと隣接するエリアの下でのテレシーズミックシーザー波の分散を利用しています.
- リトスフィア-アステノスフィアの境界とリトスフィアの厚さの変動を解決する.
主要な成果:
- 裂け目地域の下では,実質的で横方向に急激な石層の薄めが観察されました.
- サルトン・トラフで効率的な菌株の局所化が確認され,マントルの石層が薄くなり,新しい石層が形成された.
- 表面と深層の石層の変形の間の体系的なオフセットは見つかりませんでした.
結論:
- 結果は,対称性のある石層拡張と一致しています.
- 主要な変形メカニズムとして,片方向の浅い沈み切断ゾーンに沿った単純な切断を排除した.
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