OXYGEN AND SULFUR ISOTOPE ANALYSES OF QUARTZ AND PYRITE AT THE HAILE GOLD MINE, LANCASTER COUNTY, SC

Gold mineralization at the Haile Gold Mine is associated with silicified and fine-grained pyrite bearing metasediments of the Richtex formation near the contact with the older metavolcanic Persimmon Fork Formation. The origins of mineralization at Haile and similar deposits in the Carolina terrane have been attributed to either epithermal or orogenic systems. Due to the association of gold with quartz and pyrite and the ability to characterize the source of fluids responsible for formation of those minerals using stable isotope data, 138 quartz samples and 17 pyrite samples were analyzed. Quartz samples were selected from the various styles and stages of silicification present at Haile. δ¹⁸O quartz values ranged from +5.9 to +9.1 per mil and δ³⁴S pyrite values ranged from -1.6 to +3.4 per mil. Assuming silicification occurred at temperatures in the range 200-400°C to account for either an orogenic or epithermal system and the lower greenschist facies metamorphic grade of the host rocks, calculated δ¹⁸O fluid values are consistent with quartz forming from a mixture of magmatic and meteoric fluid, which is typical of epithermal systems. These δ¹⁸O fluid values are inconsistent with the range of values typically associated with orogenic deposits or metamorphic devolatilization reactions. The δ³⁴S values for pyrite indicate mineralization from a predominantly magmatic source while positive values have been interpreted to indicate seawater enrichment. These oxygen and sulfur isotope values are consistent with mineralization in an epithermal system.