Fluid origin and evolution of Cu-Pb-Zn mineralization in rhyolite breccias in the Lón area, southeastern Iceland

Our results indicate that early-stage, mineralizing fluids derived from a mixture of meteoric water, seawater, and a minor magmatic water component exsolved from an evolved anatexis-produced melt. Late-stage fluids were derived exclusively from meteoric waters. Although anatectic dehydration melting of altered basalt produced millions of years of felsic magmatism in southeastern Iceland, only hydrothermal fluids that derived from a mixture of meteoric water, seawater, and brine exsolved from a highly evolved melt concentrated base metals in significant quantity to produce base metal sulfide mineralization.