Date/heure
Date(s) - 2 avril 2026
13 h 15 min - 14 h 15 min
Catégories
2 Avril 2026, 13h15 amphithéâtre du CRPG | Ilya Bindeman (University of Oregon, USA)
Coevolution of crustal maturation and surface environments based on the triple oxygen isotope records of surface archives
Abstract: Sometimes during the Archean, Earth shifted from an early “water world” to a hypsometrically bimodal planet, where subaerial continents emerged. The available sedimentological record of shales, glacial diamictites, and detrital zircon provides isotopic and petrological insights showing that the crust was becoming more silicic and exposed as it evolved over time, primarily driven by planetary cooling and the start of horizontal tectonics. The critical tipping point of emergence was reached at the end of the Archean with the formation of the first supercontinent. Exposed large swaths of subaerial crust, initiated surface weathering as an important new geochemical flux regulating climate, and influenced the proliferation of lifeforms on early Earth via habitat creation.