深い大陸の石層マントルの羽根駆動による再構成

Jingao Liu^1,2, D Graham Pearson³, Lawrence Hongliang Wang⁴

¹State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing, China. jingao@cugb.edu.cn.

Nature

|April 29, 2021

まとめ

クラトンと呼ばれる古代の大陸は破壊された後に回復しますこの研究ではマントルの羽根がクラトンの石層の厚さを取り戻すのを助け地球の歴史における広範囲にわたる過程を明らかにしています

科学分野:

地質学
地理学
構造学

背景:

クラトンは古くて安定した大陸の塊で深いマントルの根源を持っています
クラトンの石層は薄くなるが,しばしば元の厚さに戻る.
クラトン石層破壊のメカニズムは知られているが,回復 (再クラトン化) はよくわかっていない.

研究の目的:

クラトニクスフィアの破壊と再クラトニクスの過程を調査する.
破壊的な出来事にも関わらずクラトンがどのように厚さを保っているかを理解します
クラトンの進化におけるマントルの羽根の役割を明らかにする.

主な方法:

北極カナダのキンベルライトによるマントルのクセノリトの分析.
スレーブ・クレートンの横断部分での地震学的な研究
プーム-リトスフィアの相互作用の数値モデリング.

主要な成果:

スレーブ・クレートンの下の石層マントルを破壊し再構築する上で重要な役割を果たした.
数値モデルでは,マッケンジー噴霧事件の浮動的な溶融残留物が薄れた石層に捕らえられたことを示しています.
断裂後のクラトニックヒーリングと厚さの回復のプロセスが特定されました.

結論:

羽根誘発の上流は,クレートンの石層マントルを破壊し,その後再クレートンを形成する.
浮遊する溶融の残留を捕獲することで,薄まった石層の回復が容易になります.
この治癒プロセスは,クレートンの長期的な安定性と複雑な構造に寄与する広範なメカニズムである可能性があります.

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