The pre-Columbian Indian societies that once lived in the Amazon rainforests may have been much larger and more advanced than researchers previously realized. Together with Brazilian colleagues, archaeologists from the University of Gothenburg have found the remains of approximately 90 settlements in an area South of the city of Santarém, in the Brazilian part of the Amazon.
"The most surprising thing is that many of these settlements are a long way from rivers, and are located in rainforest areas that extremely sparsely populated today," says Per Stenborg from the Department of Historical Studies, who led the Swedish part of the archaeological investigations in the area over the summer.
Traditionally archaeologists have thought that these inland areas were sparsely populated also before the arrival of the Europeans in the 16th and 17th centuries. One reason for this assumption is that the soils found in the inland generally is quite infertile; another reason is that access to water is poor during dry periods as these areas are situated at long distances from the major watercourses. It has therefore been something of a mystery that the earliest historical account; from Spaniard Francisco de Orellana's journey along the River Amazon in 1541-42, depicted the Amazon as a densely populated region with what the Spanish described as "towns", situated not only along the river itself, but also in the inland.
NEW DISCOVERIES COULD CHANGE PREVIOUS IDEAS
The current archaeological project in the Santarém area could well change our ideas about the pre-Columbian Amazon. The archaeologists have come across areas of very fertile soil scattered around the otherwise infertile land. These soils, known as "Terra Preta do Indio", or "Amazonian Dark Earth", are not natural, but have been created by humans (that is, they are "anthrosols").
"Just as importantly, we found round depressions in the landscape, some as big as a hundred metres in diameter, by several of the larger settlements," says Stenborg. "These could be the remains of water reservoirs, built to secure water supply during dry periods."
It is therefore possible that the information from de Orellana's journey will be backed up by new archaeological findings, and that the Amerindian populations in this part of the Amazon had developed techniques to overcome the environmental limitations of the Amazonian inlands.
ARCHAEOLOGICAL RESCUE EFFORTS ARE URGENT
The archaeological sites in the Santarém area are rich in artefacts, particularly ceramics. A large and generally unstudied collection of material from the area is held by the Museum of World Culture in Gothenburg. Collected in the 1920s by the Germano-Brazilian researcher Curt Unkel Nimuendajú, the material ended up in the Museum of Ethnography in Gothenburg and is essential for increasing our knowledge of the pre-Columbian Amazon. Brazilian researchers are therefore interested in joint projects, where new field studies are combined with research into the contents of the Museum of World Culture's collections from the same area.
The investigation area is situated near the city of Santarém, between the Amazon mainstream and its tributary; Rio Tapajós in northern Brazil. Maps: Per Stenborg.
"The Santarém area is presently experiencing intensive exploitation of various forms, including expansion of mechanized agriculture and road construction," says Dr. Denise Schaan at Universidade Federal do Pará. "This means that the area's ancient remains are being rapidly destroyed and archaeological rescue efforts are therefore extremely urgent."
"Our work here is a race against time in order to obtain archaeological field data enabling us to save information about the pre-Columbian societies that once existed in this area, before the archaeological record has been irretrievably lost as a result of the present development", states Brazilian archaeologist Márcio Amaral-Lima at Fundação de Amparo e Desenvolvimento da Pesquisa, in Santarém.
Explore further: 110-million-year-old crustacean holds essential piece to evolutionary puzzle