12:00 PM - 12:15 PM
[HTT16-12] Origin of prehistoric pottery clay deciphered from Sr-Nd-Pb isotope ratios
Keywords:Jomon and Yayoi pottery, Sr-Nd-Pb isotope ratios, source of clay material
In archaeological research, it is important to know the production place of pottery and the clay source for discussing the migration, distribution of goods, and exchange in each era. Among the Jomon and Yayoi pottery in western Japan, a pottery group called "Ikoma seirokusan" has a brown color characterized by amphibole-rich pottery. It is thought that this pottery group was manufactured in villages in the western foot of Mt. Ikoma (Higashi-Osaka City, etc.) in the eastern part of the Osaka Plain and distributed in each area centered on the Kinki region. Clay sources of the pottery group have been estimated from the viewpoint of archaeological observation, texture analysis of sand grain, X-ray fluorescence analysis, etc. Until now, these methods cannot identify their origin.
We analyzed the production locality of the pottery using Sr (strontium) -Nd (neodymium) -Pb (lead) isotope analysis, which has different isotope ratios depending on the geology and the age of the formation. In this presentation, we report the radiogenic isotope analysis of Jomon and Yayoi pottery excavated from the two regions. One is the eastern part of Osaka Plain on Mt. Ikoma's west side, and the other in the northeastern part of the Kyoto Basin on the west side of Mt.Hiei. We have measured with bulk samples, separated amphiboles, and matrix clay to verify amphibole effects.
As a result of the analysis, the isotopic difference observed between the pottery from "Ikoma seirokusan" and "Hi-Ikoma seirokusan"(none Ikoma seirokusan pottery). The former's Sr-Nd isotope ratios are included in the range of the Ikoma gabbro's isotopic values. A few separated amphiboles and matrix clay from the same sample have different isotopic values from each other and their bulk isotopic values. With a new data set of lead isotope ratios, grain analysis of sand, and X-ray fluorescent analysis of the bulk samples, we will evaluate the effectiveness and the prospect of the radiogenic isotope analysis to estimate the origin of source materials.
We analyzed the production locality of the pottery using Sr (strontium) -Nd (neodymium) -Pb (lead) isotope analysis, which has different isotope ratios depending on the geology and the age of the formation. In this presentation, we report the radiogenic isotope analysis of Jomon and Yayoi pottery excavated from the two regions. One is the eastern part of Osaka Plain on Mt. Ikoma's west side, and the other in the northeastern part of the Kyoto Basin on the west side of Mt.Hiei. We have measured with bulk samples, separated amphiboles, and matrix clay to verify amphibole effects.
As a result of the analysis, the isotopic difference observed between the pottery from "Ikoma seirokusan" and "Hi-Ikoma seirokusan"(none Ikoma seirokusan pottery). The former's Sr-Nd isotope ratios are included in the range of the Ikoma gabbro's isotopic values. A few separated amphiboles and matrix clay from the same sample have different isotopic values from each other and their bulk isotopic values. With a new data set of lead isotope ratios, grain analysis of sand, and X-ray fluorescent analysis of the bulk samples, we will evaluate the effectiveness and the prospect of the radiogenic isotope analysis to estimate the origin of source materials.