The origin and construction of pre-Hispanic mounds in the Upper Delta of the Paraná River (Argentina)

Abstract

Pre-Hispanic mounds, known as “cerritos,” “cerritos de indios,” or “aterros” across southeastern South America, are one of the most conspicuous and well-studied cultural manifestations in lowlands archaeology. Nevertheless, in the Upper Delta of the Parana River, mounds are rarely studied, and even their anthropic origin is under debate. This could be related to the fact that anthropogenic mounds are located on a floodplain where other “mound-like” natural geoforms (generated by fluvial processes) are also present. In addition to this, the natural geoforms also contain evidence of Holocene human occupation (sherds, bones, charcoal, humans burials, etc.), which can lead to interpretive errors of their origin and formation. Thus, this project set out to determine the genesis and evolution of these mounds and also to identify the cultural occupation and transformation of natural landforms found in the area. In this article, natural and anthropogenic systems and processes were identified and characterized through the application of proxy record analysis (i.e., sediment composition, stratigraphy, micromorphology, silica bodies and chronological analysis) at the Los Tres Cerros archaeological locality in the Upper Delta of the Parana River of Victoria County, Entre Rios Province, Argentina. This analysis allowed for the recognition of natural anthropogenic interfaces, such as the “pre-mound” occupation as well as evidence of cultural activities such as mound construction, between 1,000 and 500 14C years bp. These findings were integrated into current research on the variability of mound construction during the Late Holocene in the lowlands of South America.