Solstad, a Co-Se-bearing copper ore in the Västervik quartzites, Sweden

The Solstad copper deposit, located in SE Sweden, is hosted by a quartz-rich rock sliver surrounded granite belonging to the 1.8 Ga Transscandinavian Igneous Belt. Ore petrographic studies have revealed number of previously unrecognized opaque phases, including several Co selenides and tellurides. Based on an situ U-Pb investigation zircons from mineralized sample, it suggested that detrital origin host xenolith c. 1.88–1.86 Västervik quartzite formation. A low-radiogenic galena sample implies source for metals ore has primitive origin, probably basaltic lavas (now amphibolites) are intercalated quartzite. Fluid inclusion quartz distinguish four distinct fluids: (1) hypersaline halite-bearing aqueous fluid related early (1.85–1.86 Ga) chalcopyrite depositional stage, (2) subsequent CO2-rich fluid, deposited native gold, tellurides, bismuthinite, developed (at ≥1.8 as result phase separation, (3), moderate- high-salinity did also develop at this event led deposition bornite (4) concluding, low-salinity stage ≤1.8 caused oxidation covelline digenite formed phases. It proposed deposit other Cu ± Co-rich sulphide (± magnetite) occurrences region along southernmost margin 1.9–1.8 Svecofennian Domain, represent type associated with quartzites amphibolites.