The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary

A significant shift in the recycling of Earth's surface materials into its interior occurred around 3230 million years ago, marking a pivotal moment in the planet's tectonic history. This discovery is supported by zircon oxygen isotope analysis from early Archean igneous suites in the Kaapvaal Craton, southern Africa. The study found that zircon δ18O values abruptly increased at the Paleo-Mesoarchean boundary, indicating the onset of deep recycling of hydrated oceanic crust. This process, characterized by low-temperature water-rock interaction, suggests a fundamental change in tectonic dynamics during craton formation and stabilization, potentially reflecting the early operation of plate tectonics on Earth.

Wang, X., Tang, M., Moyen, J., Wang, D., Kröner, A., Hawkesworth, C., Xia, X., Xie, H., Anhaeusser, C., Hofmann, A., Li, J., & Li, L. (2021). The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary. National Science Review, 9(3). https://doi.org/10.1093/nsr/nwab136