Modern-style subduction during the late Neoarchean to early Paleoproterozoic? Geochemical evidence from ca. 2.45 Ga arc-type magmatism in the Feidong Complex, northeastern Yangtze Craton, South China

Modern style subduction occurred within the northern margin of the Yangtze Craton at least by the late Neoarchean to early Paleoproterozoic (ca. 2.50–2.45 Ga). Dehydration of subducting oceanic slab material caused the partial melting of the mantle wedge, with the resulting mantle-derived magmas underplating the overlying crustal, causing partial melting of this crustal material and the generation of calc-alkaline magmas, such as the protolith of the orthogneiss in the Feidong Complex in this study. Moreover, the dehydration of the subducting slab mantle at depth caused the partial melting of the overlying thickened lower crustal material and the generation of TTG magmas, such as the Douling TTG rocks.