Magmatic hydrothermal evolution of the Anjerd Cu skarn deposit, NW Iran: Perspectives on mineral chemistry, fluid inclusions and stable isotopes

•The Anjerd skarn shows three sequential stages including (i) prograde, (ii) early retrograde, and (iii) late retrograde.•The early stage recognized by high–temperature and saline magmatic fluid, whereas the late stage by low temperature and low salinity meteoric fluids.•The δ18OH2O and δDH2O values indicate that magmatic fluids and mixing with meteoric fluids were largely responsible for the mineralization.•Sulfur isotopes compositions suggests a magmatic source for the sulfur.