Pre-Columbian Earthworks in the Riberalta Region of the Bolivian Amazon

Abstract

Interpretations of the Amazonia prehistory have changed significantly in the last few decades, as the complexity and diversity of the Amazonian cultures are beginning to be documented and understood. Earthworking, a long-term conscious anthropogenic landscape alteration, was a widespread phenomenon throughout the South American tropical lowlands. A variety of earthworks has been documented in the Southwest Amazon, including ditches and embankments of different shapes and sizes, roads, extensive raised fields, canals, causeways, and artificial wetlands linked to adjacent mounds and forest island settlement sites. A field survey and test excavations were undertaken in the region of Riberalta, in the Bolivian Amazon. The purpose of these investigations was to study the distribution and characteristics of the pre-Columbian occupation in the region. We found different types of sites, some without visible earthworks, indicating fairly dense occupation on river bluffs and terra firme, but lacking long permanence in the same location. The earthwork tradition prevailed in the Riberalta region from at least 100 B.C. until the period of European contact. The function of the less-complex earthworks may have been to enclose the occupation areas, and in some cases, to serve as canals. Compared to the variable layout of the sites, the ceramic assemblages of the region are relatively homogeneous. A central objective for future research will be to determine if the earthwork sites correlate with a single or multiple cultural traditions.Key-words: Southwest Amazonian archaeology, earthworks, ceramic traditions.