2023-09-21 ペンシルベニア州立大学(PennState)
◆研究は岩石の記録データを用いて行われ、地殻の成長曲線を再評価しました。この研究により、地球の地殻とマントルの成長に関連性があることが示唆され、地球の進化における重要な情報が提供されました。同様のアプローチが他の惑星の研究にも応用され、地球と比較しながら惑星の進化に関する洞察が深まる可能性があります。
＜関連情報＞
- https://www.psu.edu/news/earth-and-mineral-sciences/story/earths-crust-tectonic-plates-gradually-formed-geoscientists-find/
- https://www.geochemicalperspectivesletters.org/article2324/
大陸成長の全岩石圏的見解 A whole-lithosphere view of continental growth
J.R. Reimink, J.H.F.L. Davies, J.-F. Moyen, D.G. Pearson
Geochemical Perspectives Letters Published:3 August 2023
DOI:https://doi.org/10.7185/geochemlet.2324
Abstract
Continental crust is a defining feature of Earth; yet, the mechanisms that control its growth remain hotly debated. Many approaches to estimating crustal growth focus solely on a single mineral—zircon, while constraints from the lithospheric mantle root remain largely neglected. Here, we critically examine the ability of zircon to accurately record the relative roles of juvenile crustal addition versus recycling, and present an alternative approach based on the geochemistry of crustal rock samples. The resulting model of continental crustal growth parallels, but pre-dates, the pattern of cratonic mantle lithosphere formation ages, indicating a distinct relationship between the continental crust and its mantle root. Our results indicate that continental crust and deep cratonic lithospheric roots grew progressively over ∼2.5 Gyr of Earth history, with clear temporal links to the birth of extensive lithospheric keels and establishment of continental drainage basins.
