Extended Data Fig. 9: The correlations of H2O/Ce with Ba/La and Sr/Y ratios.
From: Earth’s early continental crust formed from wet and oxidizing arc magmas
Data for Archaean granitoids (orange diamonds) and Phanerozoic and Archaean PCDs (purple circles and yellow diamonds, respectively) are from this study (Supplementary Table 3), whereas data for Phanerozoic IAB (blue circles) are from ref. 32. Error bars are 2 s.e.m. a, The positive correlation between H2O/Ce and Ba/La suggests that the magma sources of Archaean granitoids were variably influenced by influx of fluids, as in Phanerozoic arc magmas. The large variations in Ba/La ratios of Archaean granitoids probably result from metamorphic disturbance of whole-rock Ba, whereas the lower Ba/La and H2O/Ce ratios of Archaean rocks compared with Phanerozoic arc magmas probably suggest that Archaean subduction was less efficient in H2O transport than Phanerozoic subduction. The dashed black line and shaded grey area are the linear regression and 95% confidence level for all data, respectively. The inset shows the distribution and correlation for the three groups of Archaean granitoids identified in the main text. b, The positive correlation between H2O/Ce and Sr/Y suggests that the H2O-rich sources of Archaean TTGs occurred in the deep lower crust or the mantle. Symbols are the same as in a.
