Fluid-rock interaction, skarn genesis, and hydrothermal alteration within an upper crustal fault zone (Island of Elba, Italy)

•The Zuccale fault is an example of a regional fault that hosts a hydrothermal magnetite-hematite deposit (Terranera).•In this fault ore precipitation occurred at 350–180 °C , but goethite and clay minerals formed at lower T.•The ore-forming environment that was transitional between that of a magnesian Fe-skarn and that of an epithermal deposit.