炭素とシリコンの循環の進化に関するリチウム同位体の視点
Boriana Kalderon-Asael1, Joachim A R Katchinoff2, Noah J Planavsky3
1Earth and Planetary Sciences, Yale University, New Haven, CT, USA. boriana.kalderon-asael@yale.edu.
Nature
|July 15, 2021
まとめ
リチウム同位体の記録は,地球の炭素とシリコンのサイクルにおける長期的な変化を明らかにし,プレカンブリア時代から現代のプロセスへの移行を示しています. この進化はシリコンの生物学的制御と 陸上の植物の出現と関連しています
科学分野:
- 地化学
- 古代気候学
- 地球科学
背景:
- 地球の炭素とシリコンの循環は 地球の長期的な気候の安定に影響します
- これらのサイクルのフィードバックメカニズムと量的な制約は,まだ十分に理解されていません.
- リチウム同位体の記録は これらの元素のサイクルを 追跡するための新しいプロキシを提供します
研究 の 目的:
- リチウム同位体の記録を利用して,炭素とシリコンの長期進化を調査する.
- 過去30億年にわたる 炭酸塩ベースのリチウム同位体記録を 確立するためです
- リチウム同位体値の観測傾向の背後にある要因を理解する.
主な方法:
- 多様な層学単位から600以上の浅水海洋炭酸塩のサンプルを分析した.
- 炭素酸性リチウム同位体記録の構築
- 質量バランスモデリングで,同位体トレンドを解釈する.
主要な成果:
- 地質学的時間における炭酸リチウム同位体値の有意な増加が確認された.
- この傾向は,海水におけるリチウム同位体条件の進化に起因する.
- データは,プレカンブリア時代から現代の炭素とシリコンのサイクルへの移行を示唆しています.
結論:
- リチウム同位体の記録は 地球の進化する炭素とシリコンのサイクルに 重要な洞察を与えてくれます
- 観察された傾向は,これらの生地化学的サイクルにおける根本的な変化を反映しています.
- この移行は,生物学的に媒介されたシリコンサイクルと陸上の植物の出現と関連している可能性があります.
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