Mg isotope evidence for carbonate recycling into sub-arc mantle beneath the Ryukyu subduction zone

Fig. S1. SiO2 versus 87Sr/86Sr plots (a) and SiO2 versus 143Nd/144Nd plots (b) of the studied samples and literature data. The symbols and cited literature are the same as in Fig. 1. These plots indicate that crustal assimilation has a minor influence on the magmatic evolution of basalts from MOT, SOT, and NTVZ, but is a major factor for andesites from KST and dacite from SOT.<br> Fig. S2. MgO versus other oxides diagrams for the studied samples and cited literature data. The symbols and cited literature are the same as in Fig. 1.<br> Fig. S3. An enlarged figure shows the mixing modeling of the depleted mantle and subducted enriched components. Mixing curves are marked in 10% increments. Subducted enriched components consist of altered oceanic crust (A) and dolomite-rich carbonate sediment (D), where the proportion of dolostone sediment is 20-40%. Three mixing lines between the depleted mantle and low δ26Mg carbonate end members (calcite, magnesite, and dolomite) are shown, which suggests that the injection of magnesite and calcite in the mantle is not the main factor to produce low-δ26Mg volcanic rocks. The isotopic ratios and element concentrations of all end-members can be found in Table 2. <br> Table 1. Mg isotopic compositions of volcanic rocks from Ryukyu subduction zone.<br> Table 2. Parameters for the mixing calculations.<br> Table S1. Major, trace elements and Sr-Nd isotopic compositions of volcanic rocks from Ryukyu subduction zone.