THE HAILE GOLD MINE, SC, USA: AN EXOTIC, OVERTURNED, AND POLY-FOLDED, LATE NEOPROTEROZOIC EPITHERMAL GOLD DEPOSIT

Recent age constraints on the geologic history and timing of mineralization at the Haile gold deposit in South Carolina has changed previous interpretations on the origins of gold mineralization. Seven Re-Os molybdenite ages from mineralized metasedimentary rocks at Haile (Mobley et al., 2014) yield ages ranging from 529 to 564 Ma. Four of these samples yield a proper isochron that gives a weighted age of 548.7 + 2 Ma. Broadly correlative Mo and Au abundances in drill samples produced during previous exploration at Haile, and the common presence of molybdenite in Au-bearing horizons indicate that Au mineralization probably also occurred within the same time window for molybdenite formation. A Re-Os weighted age of 548.7 + 2 Ma for molybdenite formation establishes a close chronological association between Au mineralization and the published time window of 551-555 Ma (Ayuso et al., 2005) for peak magmatism in the Haile area, indicating that the gold mineralization is closely linked to regional late Neoproterozoic volcanism. These results indicate that the hydrothermal system that produced the Haile deposit was driven by volcanism at a time when the Carolina Terrane, which is exotic to North America, was still in a peri-Gondwana location long before the generally accepted mid to late Paleozoic accretion of the terrane to Laurentia. Metasedimentary rocks hosting Au mineralization at Haile are overlain by metavolcanic rocks, yet some detrital zircons within the underlying metasedimentary rocks yield a much younger age of 526 + 7 Ma (Mobley et al., 2014), which conflicts with the establish time window for peak magmatism and the age of Au mineralization. This conflict is interpreted to be the result of folding, which is supported in drill core observations, and indicates that the stratigraphic section is overturned at Haile.