REGIONAL GEOPHYSICAL STUDIES IN THE HAILE GOLD MINE AREA

While high resolution potential field data (gravity and magnetics) have been shown to be only modestly effective at small scales in exploration for disseminated sulfides, there is a strong regional correlation between high amplitude gravity and magnetic anomalies and the most productive gold mines in the Carolina Slate Belt. Airborne EM methods have also been shown to be effective in distinguishing sedimentary from volcanic-dominated sediments in the metamorphic rocks of the Slate Belt. 3-D forward and inverse models using EM, gravity and magnetic data sets provide useful information on the regional and local geology surrounding the Haile gold mine area. For example, using a combination of gravity to map the deeper structure of the granite and magnetics to identify the shallow edges of the granite plutons, models have been generated for the Liberty Hill and Pageland granite plutons. Both granite plutons appear to be mushroom-shaped intrusions, flaring outward from feeder pipes or chambers at low angles (less than 15 degrees) in the shallow subsurface over underlying metamorphic rock. These granite laccoliths have been eroded down to their current shapes, leaving thin, round, disc-shaped shaped bodies with large feeder pipes beneath them, which appear to extend down to 5 to 10 kilometers in depth. Although potential field models are inherently non-unique, the large density contrast between the granite plutons and the surrounding metamorphic rocks as well as the available constraints in the area resulted in a reliable boundary model. The structure of these granites indicates that it may be possible that exploitable mineralization is hidden relatively close to the surface beneath a relatively thin layer of granite.