SULFUR ISOTOPE GEOCHEMISTRY OF THE HAILE GOLD MINE, SOUTH CAROLINA: POSSIBLE MAGMATIC ORIGIN OF SULFUR

The Haile Mine is one of several gold mines located in the Carolina slate belt of South Carolina. The Carolina slate belt is characterized by late Precambrian to early Cambrian felsic metavolcanic rocks which underwent lower greenschist facies metamorphism. Gold in the Haile mine occurs in stratabound metavolcaniclastic horizons spatially associated with siliceous or pyritic ores. Deformation and metamorphism have made determination of the tectonic setting in which Carolina slate belt metavolcanics accumulated difficult, and previous workers have proposed models ranging from subaerial geothermal systems to sea floor hydrothermal systems. Sulfur isotope data was obtained from pyrite and molybdenite sampled from highly siliceous horizons in the main Haile pit. d³⁴S values ranged from 0.40 to 0.10 ⁰/₀₀ in molybdenite and -2.4 to 2.4 ⁰/₀₀ in pyrite and show little variation. The low d³⁴S values at Haile mine suggest a magmatic sulfur origin. Ore deposits that are the result of meteoric, metamorphism, or sedimentation activity typically show a wider range of d³⁴S values and tend to be higher. This magmatic sulfur may have been part of a hydrothermal sulfide system, such as a hot spring or submarine volcanic eruption, in which leaching of sulfur from igneous sulfides ultimately led to the formation of ores at Haile mine.