The high SiO2, and low MgO, Cr, and Ni contents of the Huichizi granitoids are quite similar to adakites derived from metabasaltic sources (Fig. 9). Moreover, there gamma-Secretase inhibitor IX close agreement in the initial 87Sr/86Sr and εNd(t) values of the Huichizi granites and the Neoproterozoic metabasalts of the NQ terrane (Fig. 7). Therefore, the Neoproterozoic metabasalts can be regarded as a potential source, which might, at small degrees of partial melting, produce melts resembling the Huichizi granitoids. Furthermore, the oxygen isotope composition of zircons from the Huichizi granitoids (average δ18Ozir values = 6.09 ± 0.14‰) is only slightly elevated relative to δ18Ozir values of mantle zircons (5.3 ± 0.6‰, 2σ, Valley et al., 2005) (Fig. 10b) and the εHf(t) values of the magmatic zircons in the Huichizi granitoids also overlap the same range as those of the metabasalts (Fig. 8), suggesting that their sources were similar to the Neoproterozoic basaltic rocks.
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