Trace element geochemical characterization of southeastern pegmatitic muscovite and resultant implications for the provenancing of archaeological mica

Pegmatitic muscovite is a common component of Mississippian period archaeological sites. Where encountered, such archaeological muscovite has often been attributed to an assumed Spruce Pine (North Carolina) source. Large crystals of pegmatitic muscovite, however, occur over a wide geographic range throughout the southeastern United States from Virginia through Alabama. In the case of muscovite artifacts from the Etowah mounds in northwest Georgia, Georgias muscovite-bearing pegmatite districts provide a local alternative source to Spruce Pine. Non-destructive portable X-ray fluorescence spectroscopy (pXRF) has been utilized in both the trace element geochemical characterization of muscovite from two of Georgias pegmatite districts (as well as from Spruce Pine) and in the quantitative analysis of Etowah muscovite artifacts. On the basis of principal components analysis (PCA) and discriminant function analysis (DFA), the Etowah micas have been shown to display a geochemical signature more consistent with a local Georgia source than a Spruce Pine source.