The influence of meteoric water on skarn formation and late-stage hydrothermal alteration at the Evciler skarn occurrences, Kazdag, NW Turkey

Skarn ore deposits are generally characterized by two distinctly different alteration styles: an early prograde stage with anhydrous minerals, such as garnet (grossular/andradite) and pyroxene (diopside/hedenbergite), which forms in the presence of relatively high-temperature fluid and; a later retrograde stage with hydrous minerals, such as epidote, amphibole (actinolite), and chlorite (from most to least abundant) plus sulfides, which forms in the presence of the lower-temperature fluid. These two alteration stages commonly have been thought to reflect a dominance of magmatic and meteoric water, respectively, with relevance to the source of ore metals.