Provenance and ceramic technology of pot sherds from ancient Andean cultures at the Ambato valley, Argentina

Pottery sherds from the archaeological sites El Altillo (100±70 AC, radiocarbon age) and Piedras Blancas (ca. 600–1000 AC), in the Ambato valley, and two local clay resources were characterized for their mineralogy, chemistry and thermal behavior. Raw materials used were the local red clays with additions of mostly grit from the local off-white clays. Firing ranges of around 600, 700, 700–800 and 900–1000 °C were inferred from the mineralogy and SEM textures; TGA analyses did not help in inferring firing temperatures. No significant changes were observed in the ceramic technology; it does not reflect the socio-political changes that occurred in the IVth century, which are expressed in the iconography. This suggests the continuity of the ceramic tradition, which was based on a good usage of natural resources and a knowledge of their properties over a period of 1000 years.