Locational analysis of late Holocene archaeological settlements in the lower Paraná fluvial system: The role of geomorphology and resource distribution

Research in the South American lowlands has grown considerably alongside the incorporation of new technologies and analytical methods. Nevertheless, studies focusing on site location and associated settlement patterns in the region’s extensive wetlands remain limited. This paper presents the results of the first locational analyses, using GIS-based analysis to assess topographic prominence, visibility to and from the sites, and geomorphological classifications, from 86 archaeological sites in the alluvial plain and island sectors of the lower Paraná River. The aim was to evaluate the extent to which these factors have influenced site location and distribution, and by extension, the decision-making underlying subsistence practices and territorial organisation. The results show that sites occupy the highest ground, although their relative altitude does not differ significantly from that of the surrounding terrain. We interpret these locations as choices made for protection against periodic flooding, while remaining close to shallow lakes zones where resources were concentrated. Visibility from sites drops off with distance, reaching no more than 10 km. More than 90 % of the sites are visible from the fluvial network, indicating intervisibility between settlements and the fluvial network within a 5000 m radius. This may suggest a pattern of territorial organisation more closely linked to the riverine transport network. Visibility from each site to the surrounding landscape appears to be closely linked to resource availability, whereas visibility of sites from the fluvial network is more closely tied to control and territorial organisation. By contrast, intervisibility among sites—understood as landmarks—may be connected to memory and ancestral ties, contributing to group identity and belonging.