The Dorn Mine, a historic gold mine in McCormick, South Carolina, was mined in the 1850’s, 1870’s and 1930’s. Over $900,000 of gold was mined from the area making it the second largest gold mine in South Carolina. The Dorn Mine is in the Carolina Slate Belt, a northeast trending series of rocks characterized by metavolcanics. In the 1970’s, exploration for massive sulfides containing zinc, lead, copper, and/or gold and silver was conducted jointly by Continental Oil Company (CONOCO) and Hudson Bay Oil and Gas Company (HUDBAY). Seven exploratory drill holes were dug in the area of the Dorn Mine. Research was performed in the late 1970’s and 1980 in an area that included .84 square miles within the city limits of McCormick, South Carolina. Field mapping was conducted for the purpose of constructing a geologic map on a 1:1200 scale. Approximately 7300 feet of drill core was logged in the summer of 1978. The drill core was sampled and analyzed by X-ray fluorescence techniques to determine the major element determinations of the rocks. The mineralogy and the petrography were determined using standard techniques. Electron microprobe technology was used to determine the composition of sphalerite and garnets.

The rocks are metavolcanics and argillites. The rocks are steeply dipping and on the northwest flank of a northeast trending anticline. Metamorphic grade is Upper Greenschist facies of regional Abukuma metamorphism. Minerals present are albite, sericite, biotite, chlorite, epidote, actinolite, and spessartine. Mineralization in the area is in the form of stratabound, lenticular-shaped zones. Two modes of stratabound mineralization occur – massive and disseminated. Assay values indicate the mineralized zones are Zn-Pb, Zn-Cu, and Zn-Pb-Cu, but not Pb-Cu. The rocks have undergone extensive hydrothermal alteration as a result of fumarolic activity during deposition of tuffs in a submarine environment. Alteration is represented by chloritic and sericitic zones as well as zones of silica and epidote.