2023/11/22 by Zhongqing Wu, Jian Song, Guochun Zhao +1
Earth and Planetary Sciences · #Geological and Geochemical Analysis #High-pressure geophysics and materials #earthquake and tectonic studies
paper · pdf · doi:10.1029/2023gl105178
Abstract The origins of Archean continents and subcontinental lithospheric mantle (SCLM) were important events in the early Earth. The mechanisms for the origins of Archean continents and the SCLM remain unclear. This study suggests that these events were controlled by the evolution of the hydrous magma ocean (MO). With solidification, the basal MO eventually became gravitationally unstable because of the enrichment of water. The triggered massive mantle overturns resulted in the major pulses of the crust and thick SCLM generations. The model avoids a fatal drawback of the oceanic plateau model for the origin of continents: the source of H 2 O needed for the formation of tonalite‐trondhjemite‐granodiorite (TTG). The model can also account for why the TTG and thick SCLM basically occurred in the Archean.