HEAVY MINERALS IN NORTH CAROLINA STREAM SEDIMENTS AND THE POTENTIAL IMPLICATIONS FOR RARE EARTH ELEMENT DEPOSITS

The National Uranium Resource Evaluation project reported concentrations of uranium, thorium and many other trace elements in North Carolina stream sediments. The project did not however, characterize the mineralogy of the sites they surveyed. Today, high uranium and thorium concentrations are of interest because they generally correlate with elevated concentrations of rare earth elements (REEs). After re-sampling some of the North Carolina NURE sites with high U and Th concentrations, gamma spectrometry was used to measure the U and Th content of the new samples. While the uranium and thorium readings were not as high as those originally found, they were elevated enough to be of interest. We isolated heavy minerals, and then used the scanning electron microscope to identify high concentrations of elements of interest in samples from central and western North Carolina. We found grains high in Ce, La, Th, and P in samples from both western and central North Carolina. This mineral is likely monazite, which has previously been identified in North Carolina stream sediments. Further research will involve modal analysis of heavy minerals in North Carolina stream sediments. REEs are crucial in many technologies, and given current shortages, high concentrations in stream sediments are potentially of economic interest.