Rare Earth Elements in Ultramafic Lamprophyres

The ultramafic lamprophyres of the Illinois-Kentucky Fluorspar District (IKFD) are potential domestic sources of rare earth elements (REEs), but the role of mantle metasomatism and carbonate alteration in REE distribution is not well understood. Dr. Lukoczki’s team has employed petrographic and geochemical analyses to determine the nature of the mantle source region and timing of the carbonate mineralization. Carbonate alteration, including listwanitization and ophicalcitization, appear to play a secondary role in REE distribution. For details, find Zach Walton’s thesis here. The GEMS Lab will continue to support this research with advanced microscopic analyses, including fluid and melt inclusion studies, and Raman spectroscopy, providing insights into the processes controlling REE mineralization in the IKFD.