Provenance study of Amerindian ceramic figurines with PGNAA

Full text: Prompt gamma activation analysis facility has been developed at the Budapest Neutron Centre since 1996. Its applicability to archaeological research has already been established, supported by several studies. In collaboration with the Universidad Simon Bolivar, Venezuela it was decided to use PGNAA to determine the provenance of some prehistoric pottery figurines. From five archaeological sites excavated in the Archipelago Los Roques, almost five hundred pre-Hispanic potteries were recovered. Amerindian groups from adjacent Venezuela mainland were identified as the campsite occupants between 1200 A.D. and the European contact period. Three samples from Valencia Lake Basin and five from Los Roques were selected for preliminary research purposes. Microscopic properties of pottery such as chemical composition can give information on its origin, place of manufacture, the raw material origin, the production method and trade among others. PGAA as the most convenient non-destructive method was chosen to measure major and trace elements. Furthermore, we show that these results will contribute in assessing the origin of pottery. The samples were irradiated with a cold (20K) neutron beam of 5·107 cm-2 s-1 and the prompt gamma ray spectra were collected with a HPGe-BGO detector system. The element identification and concentration calculations were performed based on our data library. We were able to determine the major components of H2O, Na2O, MgO, A12O3, SiO2, K2O, CaO, TiO2, MnO, Fe2O3 parallel with trace elements of B, S, C1, Sc, V, Cr, Ba, Sm, Eu, Gd. According to our measurements the concentration of K2O, C1 and Cr are significantly different in the samples from Valencia Lake Basin (mainland) and in those of Los Roques After the first encouraging result a second branch of archaeological objects were investigated, from both the mainland and the islands region. In order to make the provenance study more convincing, a set of soil samples from the environment of the archaeological localities were collected and investigated with PGNAA, too. (author)