Reconstruction of Hydrothermal Processes in the Cyprus Type Fe-Cu-Zn Deposits of the Italian Northern Apennines: Results of Combined Fluid Inclusion Microthermometry, SEM-CL Imaging and Trace Element Analyses by LA-ICP-MS

Quartz from the stockwork zone of various Cyprus type volcanogenic massive sulfide deposits (Boccassuolo, Reppia, Campegli, Bargone and Vigonzano) unmetamorphosed, Jurassic Northern Apennine ophiolites was studied in order to provide details on submarine hydrothermal conditions characteristics for ore formation. Our detailed SEM-CL investigation quartz contributed a robust characterization interpretation primary fluid inclusions microthermometry data. imaging also useful reconstructing consecutive steps precipitation. The determination trace element contents according growth zoning by LA-ICP-MS constrained compositional variations parent fluids during activity. A continuously cooling regime characterized each (VMS) occurrence although minimum formation temperatures were different (Bargone: 110–270 °C; Boccassuolo: 60–360 Campegli: 110–225 Reppia: 50–205 Vigonzano: 260–330 °C), range temperature most probably depends original position sampling relation centers systems. Compositional changes are reflected methane content (0.13–0.33 mol/kg) salinity (2.6–9.3 NaCl equiv. wt. %) calcite as well changeable Al (11–1526 ppm) quartz. This study demonstrates that combined use analyses, coupled with inclusion microthermometry, can constrain forming barren stages evolving