Greber Nicolas D, Murphy Madeleine E, Storck Julian-Christopher, Reimink Jesse R, Dauphas Nicolas, Savage Paul S
Muséum d'histoire naturelle de Genève, Genève, Switzerland.
Institute of Geological Sciences, University of Bern, Bern, Switzerland.
Commun Earth Environ. 2025;6(1):382. doi: 10.1038/s43247-025-02337-7. Epub 2025 May 16.
The weathering and erosion of emerged land profoundly influences the Earth system, including the composition of the atmosphere and the type of nutrients delivered to the oceans. The emergence of land allowed for the formation of lakes and continental shelves, important habitats for the origin and evolution of life. Recent studies indicate a difference in silicon isotopes between Archean granitoids and their modern counterparts, which is explained by the incorporation of seawater-derived silica in the melting sources of the former. We show that this signature changed rapidly around 3.6 billion years ago, and that this shift is likely linked to an increase in the dissolved silicon flux from terrestrial weathering. Modeling suggests that the amount of oceanic silicon derived from terrigenous sources increased from near zero to around 32 ± 15% between 3.8 and 3.6 billion years ago. This indicates that, from this point onward, continental weathering feedbacks were established, and mass flux from land became an important source in the chemical budget of seawater, changes that likely exerted positive effects on the evolution of life.
陆地的风化和侵蚀对地球系统有着深远影响，包括大气的组成以及输送到海洋的营养物质类型。陆地的出现使得湖泊和大陆架得以形成，它们是生命起源和演化的重要栖息地。最近的研究表明，太古宙花岗岩类岩石与其现代对应物之间存在硅同位素差异，这是由于前者的熔融源中掺入了源自海水的二氧化硅所致。我们发现，这种特征在约36亿年前迅速发生了变化，而且这种转变可能与陆地风化产生的溶解硅通量增加有关。模型显示，在38亿至36亿年前，源自陆源的海洋硅含量从近乎零增加到了约32±15%。这表明，从这一时期起，大陆风化反馈机制得以确立，陆地的物质通量成为海水中化学收支的一个重要来源，这些变化可能对生命演化产生了积极影响。
