Composition and origin of ore-forming fluids in a carbonate-hosted porphyry Cu and skarn deposit; a fluid inclusion and stable isotope study of Mines Gaspe, Quebec: Economic Geology, v

Mines Gasp6 is a Paleozoic porphyry copper and skarn deposit developed almost entirely in carbonate-bearing wall rocks. The Mines Gasp6 deposit is of two types: early-stage skarn-type replacement orebodies and late-stage porphyry copper-type veins. Fluid inclusion data from Mines Gasp6 suggest hat the skarn and porphyry copper hy-drothermal systems each evolved from an early magmatic-dominated stage to a late meteoric-dominated stage. The skarn-type replacement orebodies (chalcopyrite + pyrrhotite) formed at temperatures near 850øC. Salinities of fluids associated with ore in the skarn display a complete range from 15 to 56 equivalent weight percent NaCI, suggesting progressive dilution of an early high salinity magmatic fluid by less saline meteoric water. Salinities of the porphyry copper ore fluids do not show a continuous range but instead reflect wo distinct fluids of hig