GEOCHEMICAL ANALYSIS OF MICA SOURCE SPECIMENS AND ARTIFACTS FROM THE ABBOTT FARM NATIONAL HISTORIC LANDMARK (28ME1)

Abstract

The Abbott Farm National Historic Landmark is one of the more significant Woodland-period sites in the Northeast. Numerous Hopewellian cultural traits (copper artifacts, cremated burials, exotic cherts, and mica) have been identified at the site. Numerous potential geological sources for the mica artifacts exist in the Mid-Atlantic region. We explore two analytical methods to evaluate the most likely geological sources of the mica artifacts. Source and artifact specimens were analyzed using pXRF as well as neutron activation. Our pXRF data are suggestive, but show high analytical uncertainty. We make several recommendations relevant to future attempts that would use this kind of instrument to study sheet mica. Our neutron activation results are promising and suggest that geochemical sourcing of mica has much potential. Results of both assays suggest that most of the artifact specimens recovered from Abbott Farm share a similar chemistry, and this composition is very similar to mica from southeastern Pennsylvania. A cut-and-drilled pendant exhibits a chemical makeup distinctly different from all other artifacts and source specimens evaluated here. Although our results are preliminary, the application of modern analytical methods to extant archaeological collections has the potential to provide significant new information.