Origin and evolution of ore-forming fluids in the Hemushan magnetite–apatite deposit, Anhui Province, Eastern China, and their metallogenic significance

•Analyses of fluid inclusions in the Hemushan magnetite–apatite deposit, China.•The deposit is magmatic origin, with hydrothermal metasomatic features.•Fluids in mineralization stage feature medium–high temperature and high salinity.•The ore-fluid evolved under moderate pressure (20–70MPa) at ca. 0.7–2.4km depth.•The boiling of fluids was a potential mechanism for the formation of magnetite.