Southeastern Section - 70th Annual Meeting - 2021

Paper No. 4-6
Presentation Time: 10:00 AM

OCCURRENCES OF THE RARE-EARTH ELEMENTS IN BAUXITE AND KAOLIN CLAYS, COASTAL PLAIN, GEORGIA


SHAFER, David L. and ELLIOTT, W. Crawford, Geosciences, Georgia State University, 38 Peachtree Center Ave, 730 Langdale Hall, Atlanta, GA 30302

Whole rock samples of bauxite, kaolin and a glassy bauxite from Wilkinson County GA contained significant amounts of the rare-earth elements, select trace (Zr, Hf, others) and major (Al, Ti) elements on a whole rock basis. The rare-earth elements (REE) were enriched in the heavy rare-earth elements (HREE: Y, Gd-Lu) relative to Upper Continental Crust (UCC) for the bauxite clays. A significant enrichment of HREE, up to twelve times relative to UCC, was observed in a previously uncharacterized layer informally referred to as “Glassy Clay. This glassy clay is a titanium-rich clay that forms a transition zone between the kaolin and bauxite layers. The total concentration of the REE for the Glassy Clay was 566 mg/kg; 602 mg/kg for the LREE-rich kaolin. These glassy clay was also significantly enriched in titanium oxide, as much as 9.5 times relative to UCC. A highly weathered surface bauxite contained an enrichment in Sc. The kaolin clays were more enriched in the light REE (Sc, La-Sm). The occurrences of the REE comprise a resource of REE which conceivably can be co-produced from the mining of kaolin and bauxite clays.