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The excavated soil is usually placed around the structure, in a kind of wall. 


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Last update: 30/04/2015

By: Júlia Morim - N/I

Geoglyphs are etches in the ground that form geometric patterns (lines, squares, circles, octagons, hexagons, etc.), zoomorphs (animals) or anthropomorphs (human forms), with monumental dimensions. The excavated soil is usually placed around the structure, in a kind of wall. The trenches can be 1 to 5 metres deep. Drawings can only be fully observed from above, particularly by flying. They are similar to the archaeological findings in Nazca, Peru.

It is believed that these structures were created in pre-Columbian times by indigenous peoples who inhabited the Western Amazon (VIRTANEN, 2008). Besides geoglyphs, many indigenous ceramics were found in archaeological sites, which would indicate the presence of ancient villages in the region. The designs can reach 350 metres in diameter, suggesting that several people were required for their construction (SCHAAN, 2008).

In Brazil, most identified geoglyphs are found in Acre. However, they have also been found in the states of Amazonas and Rondônia, which indicates that the societies that built these structures may have been spread out widely in the territory.

The first archaeological investigations in Acre began in 1977, due to the national inventory that was being conducted by the National Program for Archaeological Research in the Amazon Basin (PRONAPABA). Archaeologists Ondemar Dias and Franklin Levy from the Brazilian Institute of Archaeology (IAB-RJ), along with then student Alceu Ranzi from the Federal University of Acre, began the search for archaeological sites in the region.

Even in these early expeditions, the researchers noted the circular structures in forms of ditches, but only from 1986 did the discovery of images begin to be disclosed by Alceu Ranzi, who had now become a paleontologist and professor at the Federal University of Acre. He named these structures “geoglyphs” (marks on the ground). Ranzi was flying over the area when he noticed a double circle, now known as site AC-RB-06. Impressed, Ranzi returned to fly over the area, bringing along photographer Edison Caetano, who captured the structures. This generated media interest, with newspaper covers and articles in national magazines. The professor received financial support from the Acre Government’s Cultural and Sports Incentive Law, through the Elias Mansour Foundation, which in 2001 approved the project Geoglyphs: Acre Cultural Heritage. Thus, more exploratory and registry flights were performed.

In 2006, with the advent of satellite images provided by Google Earth, the professor continued his research, being able to further catalogue these structures. In this study, he noted, for example, that the Acre River served as a divider: southeast of the river, 30 of the 32 identified geoglyphs are circular, while north of it, five of the seven are rectangular (RANZI; FERES; BROWN, cited in SCHAAN, 2008, p.26). Currently 150 geoglyphs have been recorded in Acre, but the researchers suggest that this may represent only 10% of the existing. These discoveries were only possible because of the deforestation that has occurred in the region in recent decades. Many geoglyphs may still  be hidden by natural vegetation.

Researchers continue speculating on the motivations and objectives of geoglyph construction. For possible uses, there are some hypotheses: the geoglyphs could be “ceremonial sites, fortified villages, or venues. Or maybe all these things, given their variability.” (SHAAN et al., 2007, p.76). The lack of answers suggests the need for a joint effort between archaeologists, anthropologists and related sciences to explore more deeply and unravel these mysteries.

Recife, 28 May 2014.
Translated by Peter Leamy, March 2015.

sources consulted

GEOGLIFOS. Available at: <>. Accessed: 28 maio 2014.

SCHAAN, D.; PÄRSSINEN, M.; RANZI, A.; PICCOLI, J. C. Geoglifos da Amazônia ocidental: evidência de complexidade social entre povos da terra firme. Revista de Arqueologia, n. 20, p.67-82, 2007. Available at: <>. Accessed: 4 maio 2014.

SCHAAN, Denise Pahl. Arqueologia do Acre: do pronapaba às pesquisas sobre os geoglifos. In: SCHAAN, D. RANZI, A (Org.). Arqueologia da Amazônia Ocidental: os geoglifos do Acre. Belém: Editora Universidade Federal do Pará (EUFPA); Rio Branco: Biblioteca da Floresta, 2008. p. 10-29.

VIRTANEN, Pirjo Kristiina. Observações sobre as possíveis relações entre os sítios arqueológicos do Acre e um povo Aruak contemporâneo. In: SCHAAN, D. RANZI, A (Org.). Arqueologia da Amazônia Ocidental: os geoglifos do Acre. Belém: Editora Universidade Federal do Pará (EUFPA); Rio Branco: Biblioteca da Floresta, 2008. p. 79-89.

how to quote this text

Fource: MORIM, Júlia. Geoglyphs. Pesquisa Escolar Online, Joaquim Nabuco Foundation, Recife. Available at: <>. Accessed: day month year. Ex: 6 ago. 2009.