Instrumental neutron activation analysis (INAA) characterization of pre-contact basalt quarries on the American Samoan Island of Tutuila

Abstract

This thesis presents a material-centered characterization of 120 geologic samples from four fine-grained basalt quarries on the Samoan Island of Tutuila. Previous unsuccessful attempts at definitive Tutuilan quarry differentiation have utilized x-ray fluorescence (XRF). In this study, clear differentiation of each analyzed quarry was achieved using instrumental neutron activation analysis (INAA). Biplots of canonical discriminant function scores for the INAA data illustrate clear separation based on the variation in chemical composition between each quarry. The samples analyzed not only define quarry separation, but also provide the "core group" for a preliminary baseline necessary for future artifact-centered provenance studies. Inclusion of these "core group" samples in the baseline was confirmed by stepwise discriminant analysis. These findings suggest the ability to determine quarry of origin on the island of Tutuila, which can elucidate the importance of individual Tutuilan quarries in the export and exchange of fine-grained basalts.