大陸の発掘の歴史は,数十億年以上の時間尺度で記録されています
Terrence J Blackburn1, Samuel A Bowring, J Taylor Perron
1Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. terrence@mit.edu
Science (New York, N.Y.)
|January 7, 2012
まとめ
古代の大陸石層は,地球で最も古い構造を保存しています. ウラン鉛による熱クロノロジーは,大陸の年齢と一致して,数十億年にわたって非常に低い侵食率を明らかにしています.
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.
- 地球科学 地球科学 地球科学
背景:
- 大陸の石化層は,地球で最も古く,最も安定した地質学的構造を宿している.
- これらの古代の断片は,地質学的時間尺度における地質学および地表過程の洞察を提供します.
- 浮揚,侵食,冷却の歴史を理解すると,大陸の物理的性質と発掘力のことが明らかになる.
研究 の 目的:
- 古代の石層の冷却の連続した記録を再構築するために.
- 大陸の残骸の長期侵食率を調査する.
- 地質学的時間における下層地殻の発掘を駆動する力を理解するために.
主な方法:
- ウラン鉛 (U-Pb) 熱クロノロジーは,火山によって発掘された下層地殻の断片で利用されました.
- 熱クロノロジカルデータを解釈するために,熱および鉛拡散モデルを適用した.
- 古代の石層の連続的な冷却記録を構成した.
主要な成果:
- U-Pbのデータは,非常に低い侵食率を示しています.
- これらの低い侵食率は,大陸の年齢に近づく時間スケールで持続しています.
- 発見は,古代大陸の断片の侵食の歴史の可能性を制限します.
結論:
- 大陸の石層は,驚くべき長期的な安定性を示しています.
- 侵食の速度が非常に遅いのは,古代大陸の残骸の特徴である.
- この研究は,大陸の長期的な進化と回復力を理解するための重要なデータを提供します.
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