Water/Rock interaction in Panah-Kuh skarn using carbon and oxygen stable isotopes in different calcite types, west of Yazd

The Panah-Kuh calcic and magnesian skarns are located about 50km northwest of Taft City in Yazd province. Intrusion of Panah-Kuh granodiorite stock with an Oligocene-Miocene age into limestone-dolomite rocks of the Jamal Formation led to the formation of calcic and magnesian skarn in the Panah-Kuh district. Values of δ18O of the granitic rocks and δ18O and δ13C values of the calcite types were determined in this study. Based on these data, δ18O and δ13C values in the studied calcite types are lower than those of sedimentary calcites. These isotopic variations are mainly produced by infiltration of magmatic fluids into carbonate rocks in the Panah-Kuh deposit. Depletetion of the δ18O and δ13C value in the calcite types of Panah-Kuh skarn can be explained by magmatic fluids interaction (δ18O =11.0‰) that interacted with unaltered limestone rocks at 350-450oC with X(〖CO〗_2 ) = 0.05 and water/rock ratio of 25 to 50% .