A STABLE ISOTOPE STUDY ON FLUID SOURCE AND TEMPERATURE OF THE MURGUL DEPOSIT

The Murgul deposit, located in Murgul, NE Turkey, is a copper-rich Volcanogenic Massive Sulfide (VMS) system. It has been interpreted as a Kuroko VMS system, and is one of several VMS and vein deposits found throughout the Eastern Pontides. The massive sulfide portion of the Murgul deposit has been removed by mining, but the underlying stockwork zone is significantly mineralized with chalcopyrite so the deposit remains profitable. Very little isotopic research has been conducted on this, or any other, deposit located in the region. Sulfur and oxygen stable isotope data help constrain fluid emplacement temperatures and fluid source for a better understanding of the deposit’s origin. Chalcopyrite-pyrite pairs yield an average equilibrium temperature of approximately 350^oC, with a 60^oC gradient in 100ft. Quartz-illite pairs were determined to be in disequilibrium, thus unable to provide temperature data, but illite permits calculation of a fluid source of δ¹⁸O of 8-11^o/_oo. These data suggest that there is a temperature gradient within the system and the fluids that produced the Murgul deposit were likely derived from seawater, confirming the interpretation of this system as a VMS deposit.