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Figure 1.

(A) ⁸⁷Sr/⁸⁶Sr evolution of seawater from marine limestones and fossils with respect to the mantle contribution (Shields and Veizer, 2002). Red data points are poorly constrained in age (greater than ± 50 Ma). (B) Normalized marine ⁸⁷Sr/⁸⁶Sr evolution from Shields (2007) with respect to kernel density estimate plot and histogram (Vermeesch, 2012) of cumulative U-Pb age data (n = 24,190) for the global compilation of detrital zircons analyzed in this study. Emergence of paired high dT/dP-intermediate dT/dP metamorphism and widespread ultrahigh-pressure (UHP) and blueschist metamorphism (cold subduction) from Brown and Johnson (2018), and Wilson cycle onset from Shirey and Richardson (2011).

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