Archaeological palynology of a Quaternary coastal plain in southernmost Brazil

Abstract

Discussions on the relationships between human groups and the environment are recurring Archaeology topics around the world. In South America, there is a specific kind of archaeological site called “earthen mound”, locally known as “cerritos de indios” that is ethnically linked to the Charrua and Minuano groups. They mainly cover southernmost Brazil (state of Rio Grande do Sul), Uruguay, and northeast Argentina. The study of the formative processes of these sites and their relationship with former inhabitants reveal distinct morphological and cultural characteristics in the context of each earthen mound occurrence. Thus, palynological studies associated with interdisciplinary research are important tools for understanding the environmental, and cultural dynamics of mound-builders. Within this context, this study presents new data on the formative processes and role of southern Brazilian earthen mounds by combining palynological, sedimentological, and chemical analyses. The analyses were performed on the earthen mound PSG-02 and adjacent area sediments, located on the southernmost Brazilian coastal plain, in a wetland called Pontal da Barra, at the estuary of Patos Lagoon. It was possible establish some relationships between its ancient occupation and the environmental dynamics and identify the influence of numerous environmental factors on their social dynamics. The earthen mound PSG-02, dated between 1280 ± 20 and 1859 ± 29 years BP, would probably be in a multifunctional context and was strategically located for gathering of natural resources as well as a dwelling and a funerary monument. Our findings are fundamental for understanding the interactions between earthen mound communities and the environment, filling another behavioral evolution gap of particular past human groups.