HEAVY-MINERAL DEPOSITS OF BAILEY, NORTH CAROLINA

Most of the Bailey heavy-mineral concentrations lie south, southeast, east, and northeast of the town of Bailey, North Carolina. In this area, unconsolidated Cenozoic sediments of the inner Coastal Plain unconformably overlie the roughly circular late Paleozoic Sims pluton which intrudes the older slate belt rocks of the region. The Kenly heavy-mineral deposits, south of the Bailey deposits, are probably a continuation of the Bailey deposits. The separation of the two areas of heavy-mineral concentrations most likely is the result of post-depositional stream erosion. A transgressive sea (Middle Pliocene?) reworked Cretaceous deltas and basement material in the upper Coastal Plain – lower Piedmont Fall Zone. Transgressive seas have not again approached these Fall Zone deposits since regression began in the Middle Pliocene. Reworked, highly mature material from local source areas along with material brought in by fluvial systems from more distant source areas were deposited as ore bodies within a delta complex as the Middle Pliocene sea began to recede. As sea level regressed, existing rivers were forced to change their channels and pursue new courses in order to avoid erosion resistant areas such as plutons and resistant beds with high clay content. Some coalescing of Fall Zone deltas may have taken place in closely spaced river systems prior to recession. Fluvial processes, influenced by basement highs and lows, concentrated the ore within the Fall Zone delta deposits. Tidal and wave action is believed to have been relatively inconsequential, although this would not exclude local tombolo effects. The mineralized portion of the Bailey deposit covers 12.9 square kilometers, with mineralized sand averaging 6.2 meters thick. The deposit contains 5.72 million metric tons of heavy minerals. The sediments comprising this deposit average 4.72 weight percent heavy minerals. Valuable heavy minerals comprise 65 to 70 percent of the heavy mineral suite and are comprised of ilmenite, zircon, rutile, and leucoxene.