Origin of mafic intrusions in the Micangshan Massif, Central China: Implications for the Neoproterozoic tectonic evolution of the northwestern Yangtze Block

•New Early Neoproterozoic mafic sills in the Micangshan Massif have been identified.•The mafic sills were derived from a previously metasomatized mantle wedge source.•The mafic sills were formed in a subduction-related continental arc setting.