Genesis of ca. 850–835 Ma high-Mg# diorites in the western Yangtze Block, South China: Implications for mantle metasomatism under the subduction process

High-Mg# (molar 100 × Mg/(Mg + Fe)) diorites can provide significant insights on mantle metasomatism under a subduction zone. Here we investigate the genesis of the Neoproterozoic Shuilu high-Mg# diorites in the western Yangtze Block to evaluate the role of subduction-related fluids and sediment melts acting on mantle sources during the subduction process. Zircon U–Pb dating results display new weighted mean 206Pb/238U ages of 850.1 ± 1.7 Ma,...