Pottery production on Rishiri Island, Japan: Perspectives from x-ray fluorescence studies

Energy-dispersive X-ray fluorescence (EDXRF) was used to determine the minor and trace element composition of 54 sherds of pottery dating from the Final Jomon to Okhotsk periods. The majority of the sherds came from Rishiri Island, Japan. Principal component (PC) scores were calculated using the log transformed concentration values, and groups were sought in the PC scores using kernel density estimates (KDEs). Two main groups were found in the data; linear and quadratic discriminant analysis classified both groups successfully. Significant differences in the concentrations of Cu. Fe. L. Mb, Pb, Rb, Th and Zr were found to exist between the two groups. The lack of correspondence between chronological ware types and geochemical groups implies that the same raw materials and paste recipes were in use during the Epi-Jomon and Okhotsk eras on Rishiri Island. One possibility is that the PEi-Jomon and Okhotsk potters used the same clays and tempers, since no other alternatives were available. Alternatively, the Okhotsk potters could have adopted the same paste recipes as the Epi-Jomon potters, or the Okhtosk pottery tradition could be descended from the Epi-Jomon pottery tradition.