Micromorphological study in «uru» ceramist sites in the Araguaia river, Goiás, Brazil

Abstract

Geoarchaeological studies with microscopic analysis have been crucial for the verification of soils modified by human action. Micromorphology in Brazil has been used at sites, shell mounds and sambaquis in the south and southeast of the country, in rocky shelters in the Lagoa Santa region (Minas Gerais) and at «Terra Preta» sites in Amazonas and Acre states. So-called anthropic soils play a decisive role in the processes of addition and movement of organic, mineral residues and soil management practices. To identify and interpret the various types of human marks and activities on the ground, it is important to first understand how these changes occur. In principle, human-induced soil disturbances can be caused by processes of adding materials to the soil and these are identified in the micromorphological reading of thin sections. The archaeological sites of potters are located in the Araguaia river basin. Potters settlements in Goiás state were studied in order to identify when and how these groups were implemented in the central region of the country. These studies mention the existence of a darkened soil in the sites that had not been studied by micromorphological investigations until now. The relationship between the characteristics of the Cerrado biome, with its high acidity indexes, and human occupation in a given area is important to understand the taphonomy of the soil. The use of micromorphology demonstrated that even in acidic environments, it is possible to observe post-deposition alterations, microstratigraphic events, microscopic fragments of carbon, bones, various minerals, such as calcium, phosphorous, organic compounds, and ceramic microfragments, all related to anthropic activities from the potter sites.