Mineralogical and sulfur isotopic evidence for the incursion of evaporites in the Jinshandian skarn Fe deposit, Edong district, Eastern China

• The S of the Jinshandian skarn Fe deposit is dominantly derived from evaporites.
• Amounts of Cl dominantly derived from evaporites formed the Cl-rich minerals.
• The skarn system experienced a significant incursion of evaporites.
• The incursion event occurred before or during the late prograde stage.

Evaporites have played important role in the formation of diverse metallic ore deposits, especially in the case of magmatic–hydrothermal deposits. However, the relationship between evaporites and skarn Fe deposit remains poorly constrained. In this contribution, we present new sulfur isotope data of pyrite, as well as the composition of halogen-rich minerals (scapolite and amphibole) in the Jinshandian skarn Fe deposit. The data are used to evaluate the evidence for incursion of evaporites in the skarn Fe deposit. The δ34S values for pyrite from the early and late retrograde stage range from +17.4‰ to +18.7‰ (n = 4) and +16.4‰ to +19.4‰ (n = 13), respectively. Both these values are markedly heavier than the common δ34S values of sulfides from magmatic–hydrothermal fluid, indicating that sulfur in the Jinshandian ore-forming system was mostly derived from evaporites. Compared to the amphibole from endoskarn, the scapolite and amphibole from exoskarn show high Cl content up to 4.04% and 3.01%, respectively, suggesting that the hydrothermal fluid with high NaCl content was probably derived from evaporites. The amphiboles from endoskarn are more enriched in F which is probably of magmatic in origin. The data presented in our study suggest that the hydrothermal system of the Jinshandian skarn Fe deposit probably experienced significant incursion of evaporites before or during the late prograde stage.