From margins to mainstream: understanding the Amazonian Polychrome Tradition Expansion through spatial and chronological modelling

The Polychrome Expansion marks the widespread dispersal of an emblematic ceramic style across much of Amazonia during a period of broad social transformation. Yet the timing and constituent routes for this dispersal are poorly understood, in part due to a lack of dating at many sites. Here, the authors apply computational methods to model the expansion via existing radiocarbon dates, critically examining issues of timing, travel and trade/conflict. The results, they argue, call for a reinterpretation of the Polychrome Expansion as a long-lasting and gradual process that advanced from secondary rivers and spread along main channels, eventually impacting colonial history.