ロディニアの集合期におけるカラハリとローレンシアのクレートンにおける同時代の大規模なマグマチズム
Richard E Hanson1, James L Crowley, Samuel A Bowring
1Department of Geology, Texas Christian University, Fort Worth, TX 76129, USA. r.hanson@tcu.edu
まとめ
110億年前の北アメリカと南アフリカの大規模な火山地帯は,ロディニア時代に1つの出来事があったことを示唆している.
科学分野:
- 地質学 地質学 地質学
- 地質物理学 地質物理学とは地質物理学です.
- パレオマグネティズム (古磁気学) とは
背景:
- イントラプレートマグマティズムは,マントルの羽根と結びついている.
- ロディニア超大陸は,約11億年前に結成されました.
研究 の 目的:
- ロディニアの集合期間のプラーク内マグマチズムのタイミングと範囲を調査する.
- 異なるクレートンにおけるマグマ現象が同時に起こったかどうかを判断する.
主な方法:
- 岩石の放射線年代測定法による年代測定.
- 磁気極性を決定するための古磁気分析 年代表.
主要な成果:
- イントラプレート・マグマチズムは,1,106~1,112百万年前にカラハリ・クラトン (南アフリカ) で発生した.
- このマグマティズムは,北米のクラトンにおける同様の出来事と同じ磁気極性クロンで発生した.
- このマグマイベントは,2つのクラトンにわたって200万平方キロメートルの面積をカバーしました.
結論:
- 南アフリカと北アメリカのマグマ現象は,単一の大きな火山地帯の一部であると推論されています.
- 超大陸の組立中に広範囲に広がったプレート内マグマティズムは,マントルの上流が超大陸のサイクルとは無関係に起こりうることを示しています.
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