摘要：The formation of the continental crust has been debated fordecades and attracted much attention (Dhuime et al., 2017; Foleyet al., 2002; Greber et al., 2017; Johnson et al., 2017; O'Neil andCarlson, 2017; Rapp et al., 2003; Rozel et al., 2017; Rudnicket al., 2000; Xiao et al., 2006). A recent study suggested thatthe Earth's first stable continents did not form by plate subduction(Johnson et al., 2017). Meanwhile, 142Nd suggested that maficcrust may survive for more than 1000 Ma and act as an importantsource rock for the formation of the Archean crust (O'Neil andCarlson, 2017). Given that oceanic plates are mostly youngerthan 200 Ma, mafic crust that has survived for more than 1000 Mais not likely to have been subducted. In contrast, uniform Tiisotopic compositions of shales of all ages suggest that the continental crust was felsic and, plate tectonics may have started 3.5billion years ago (Greber et al., 2017), which implies that platesubduction has contributed to the formation of the continentalcrust earlier than previous thought.
