## 5 Discussion
### Petrological Classification and Petrogenesis
In this study, the concentration of each trace element in the granitoid (acid material) was divided by that in the corresponding dark enclave pair (intermediate material). The distributions of resulting ratios are shown in Figure 11, which agree well with the distribution fields defined by the experimental two-liquid partitioning coefficients of [93; 94], as well as the elemental nations between the acid and intermediate-basic materials that indicate one immiscible liquid pair [80; 89; 96]. In addition, it was suggested that the two immiscible liquids could have parallel REE distribution patterns, whereas REE abundances in immiscible intermediate-basic liquids are much greater than those in acid liquids [80]. It can be found that the REE distribution patterns between the Dazeshan granitoids and their enclaves are markedly parallel, and the dark enclaves have much greater rare earth element (REE) and HFSE abundances than those of their host granitoids, which is similar to those for the Rostown diorite and granodiorite, representing two immiscible end-member liquids [80]. Therefore, it is logical to suggest that liquid immiscibility is a viable model to explain the chemical compositional variations between the Dazeshan granitoids and their dark enclaves. It was suggested that the dioritic enclaves formed before and during liquid immiscibility are characterized by the typical textural features of distorted angular shapes with inward pointing cusps on their edges [80; 97]. Hence, the spherical to tabular shape for the dark enclaves, which are lack of the inward pointing cusps, trapped in the Dazeshan granitoids may indicate the two immiscible end-member liquids during separation would have been almost free of crystals. Thus, the compositions of Dazeshan granitoids and their enclaves may represent those of the original melts. However, given the scarce dark enclaves in the Dazeshan granitoids, though they are widely distributed, the dioritic liquid could be an infinitesimal fraction compared to the parent; therefore, the acid liquid will have the composition approximating that of the parent magma. Figure 10: Plots for the Dazeshan granitoids and their enclaves on the Greig diagram. Fields for liquid immiscibility are from [80; 95]. All the samples of Dazeshan granitoids studied show great SiO\({}_{2}\) (>68.25 wt.%) and low MgO (<1.11 wt.%), TiO\({}_{2}\) (0.26-0.36 wt.%) and TF\({}_{2}\)O\({}_{3}\) (1.98-2.69 wt.%) concentrations (Table A1; Figure 5), as well as high (\({}^{87}\)Sr/\({}^{86}\)Sr), values (0.709361-0.709858) and highly negative \(\varepsilon\)Nd(t) values of -21.6 to -18.8 (Table 2; Figure 8), indicating their derivation from strongly evolved or crust-involved magmas. However, the almost homogeneous major and trace element concentrations within all the Dazeshan granitoids studied (Table A1), which is consistent with the petrographical homogeneity of the granitoids, as well as the insignificant negative Eu anomalies (Figure 6), suggest that no significant fractionation occurred during magma evolution. In addition, their T\({}_{\text{DM2}}\) ages vary from 2449 to 2679 Ma (Table 2), in accordance with the ages of Neoarchean- Palaeoproterozoic amphibolite- to granulite- facies basement rocks in the Jiaobei terrane, reflecting a derivation from an ancient crust. Nevertheless, the enrichment in LILE and LREE but depletion in HFSE (Figure 6), the highly positive anomaly in Pb accompanied by the strong negative Nb, Ta, P and Ti anomalies (Figure 7), as well as the low Ce/Pb ratios of 2.22-5.82 (Table A1), suggest that the granitic magmas are likely generated from the partial melting of continental crust, related to an existing subduction event. It was suggested that the mafic to felsic granulite, constituting the Archean-Proterozoic lower crust in the NCC, typically shows low K\({}_{2}\)O (average 0.8 wt.%), Rb (average 16.4 ppm), Sr (average 232 ppm) and Ba (average 193 ppm) and is strongly depleted in Zr, U and Th as well as rich in Hf [41,98].