Sulfur isotope composition of the Vizcaya and Nicol veins of Portovelo-Zaruma deposit (Ecuador)

Geological characterization of gold-bearing Portovelo-Zaruma deposit is given. Presented isotope data imply involvement of magmatic sulfur in hydrothermal Portovelo-Zaruma ore system that agrees with endogenous origin of most gold-bearing epithermal deposits of Ecuador spatially and chronologically connected with magmatic ores of Early Tertiary age.