Transect Surveys Document Precontact Guaraní Expansion into Southeastern Bolivia

Abstract Results of two archaeological surveys in southeastern Bolivia provide substantial information on migration patterns of precontact Guaraní groups into an understudied region of South America. Surveys were conducted within the rights-of-way of two pipelines across the Department of Santa Cruz, Bolivia. The pipeline corridors traversed 917 km of undeveloped areas of southeastern Bolivia, which are among the least understood in South American archaeology. In total, 71 archaeological sites were identified and tested resulting in more than 132,000 artifacts. Excavation results, radiocarbon dates, specialist analyses, and paleoenvironmental reconstruction fill a gap in our knowledge base for this crucial region of South America located at the interface between the Andes and Amazonia. Project results indicate early intrusions of small groups to the region by about 900 BC and increasingly more people by about AD 700. The Chiquitano Dry Forest was relatively densely occupied from about AD 1100 through AD 1600 compared to elsewhere in southeastern Bolivia. Our findings support and amplify other recent investigations of lowland South American precontact dispersal patterns.