Poster Text – III Encuentro Internacional de Arqueología Amazónica (EIAA) 2013 What do we know about the distribution of Amazonian Dark Earth along tributary rivers in Central Amazonia? Carolina Levis 1 , Marcio de Souza Silva 2 , Mauro Almeida e Silva 2 , Claide P. Moraes 3 , Eduardo K. Tamanaha 4 , Bernardo M. Flores 5 , Eduardo Góes Neves 4 & Charles R. Clement 1 1 Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil 2 Universidade do Estado do Amazonas, Manaus, Amazonas, Brasil 3 Universidade Federal do Oeste do Pará, Santarém, Pará, Brasil 4 Laboratório de Arqueologia dos Trópicos do Museu de Arqueologia e Etnologia da Universidade de São Paulo, São Paulo, Brasil 5 Universidade Federal do Rio Grande do Norte, Natal, Rio Grande de Norte, Brasil Abstract The Amazonas River and its larger western tributaries transport huge sediment loads from the Andes with nutrient-rich waters in their fertile floodplains. Conversely, most of the northern and southern tributaries have black or clear nutrient-poor waters and less fertile floodplains. Because of this, there is a long-held but unproven tendency in the archaeological literature to consider white-water várzeas more suitable for past human occupation than hinterlands or areas along black or clear-water rivers. Such assumptions then migrated from Archaeology to Ecology in current debates about the extent of pre- colonial human impacts on shaping the composition and structure of Amazonian landscapes. The aims of this study are to: 1) show the presence of ADEs along tributary rives; and 2) test the hypothesis that the density of ADEs along black or clear-water tributaries is comparable to that along the major white-water rivers nearby. Finally, we discuss the implications of ADEs along tributaries to understand the past human impact on current Amazonian landscapes. In this study, ADEs were mapped along 12-km long river sections of 14 tributaries of the Madeira, Solimões and Negro Rivers. Where we investigated, we found many ADE sites along tributaries and confirmed our hypothesis. Hence, the lower resource availability of tributaries may not have been a limiting factor for pre-Columbian occupation. We found that past sedentary populations established on bluffs of the lower courses of tributaries. If there were so many people along tributaries, adjacent forests on the interfluves were also manipulated in some degree by people who settled on their margins. We also suggest some attenuation of the impact left by pre-Colombian people in forests of Central Amazonia from the mouth of tributaries toward their headwaters. Our data indicate that if research projects focus more on tributaries, a significantly larger number of ADEs and other signs of past human impact in inter-fluvial areas of Amazonia will be found. We conclude that the overall density of pre-Columbian occupation and landscape intervention in Central Amazonia is being underestimated.