FOUR DECADES OF ON-GOING DEBATE ON EXPLORATION MODELS FOR SOUTHEASTERN US GOLD DEPOSITS (Invited Presentation)

With renewed interest in gold following the abandonment of the gold standard in 1971 and increased interest in the Southeastern US following the discovery of Ridgeway in the early 1980’s, and renewed exploration and mining at the historic Haile and Brewer Mines, exploration models have evolved with a broader understanding of earth processes. Prior models were highly generalized and considered Southeastern gold deposits to be basically hydrothermal to mesothermal in origin, probably related to granites. Since the late 1970s, at least 30 companies have explored for gold in the Southeast. Since then, increasingly refined models that largely relate mineralization to regional tectonic events have provided a broad context for exploration and interpretation. Additionally, and for the first time, specific models of gold genesis have been developed by Southeastern explorationists and directly applied to guide exploration programs. Clearly, no one model can be applied to the large number and variety of gold occurrences and deposits. However, most classification schemes can be grouped into exhalative, epithermal or structural models, or a mixture. Examples are well illustrated in the South Carolina Sequence, where Barite Hill represents a classic syngenetic, exhalative deposit and the Brewer an epithermal deposit with mineralization hosted in a series of breccias pipes. The Haile and Ridgeway deposits appear to have a more complicated origin. However, the vast majority of deposits do have a structural component; and careful mapping and analysis of drill core will provide clues that can be used to increase understanding of the mineralizing systems and continue exploration successes.