Hundreds of Geoglyphs Discovered in the Amazon

Hundreds of Geoglyphs Discovered in the Amazon

Introduction - Introdução

This web page was created in 2010, with additions blogged chronologically down page. First, here follows the current update after links to the most recent data file versions:

Amazon Geoglyphs XLS Excel database - amazon_geoglyphs.xls
Amazon Geoglyphs KML Google Earth placemarks - amazon_geoglyphs.kml

Updates - Atualizaçães

2025.07.29 - New 2025 high resolution satellite imagery updates have been surveyed and files updated, adding forty geoglyphs. The new satellite imagery revealed nine more geoglyphs plowed, damaged, and/or destroyed.

Vista Alegre three destroyed geoglyphs
1925 x 1521 pixels

2025.04.12 - Now more than 1,550 geoglyphs, zanjas, and mound villages are recorded in the Excel database and the KML placemarks file linked above. The 2024 high resolution satellite imagery updates in the core geoglyphs region were mostly taken during the season of optimal vegetation contrast, revealing improved detail. The recent publication of another database also contributed to the additions. I also added nineteen new aerial photos taken by Dr. Rob Walker. To sort to the placemarks with the drone photos and to those with academic citations geolocating research articles take note in the Google Earth Places menu of the balloons with background color.

Photo credit: Dr. Robert S. Walker

The improved resolution of the 2024 satellite imagery with optimal season vegetation contrast revealed more embankment (terraplen) geoglyphs, earthworks without ditches (zanjas), and roadway berms leading to the enclosures. These geoglyphs are not as easily detected in satellite imagery and also more susceptible to destruction. Some of these geoglyphs in the updated satellite imagery were already destroyed by agricultural plowing before they were discovered, including one of the very largest oval monuments. The issue of illegal geoglyph destruction gained attention last year in a major Brazilian media outlet.

2024.09.25 - The Uncertain Future of Ancient Geoglyphs - Watch - 10:04
"... one archeologist (Antonia Barbosa, IPHAN) is fighting to protect ancient sites from Brazil's seemingly unstoppable agribusiness industry ....

I recently reviewed all the geoglyph placemarks to create a KML file of those damaged and destroyed. The result is a listing of forty nine structures, one of every thirty geoglyphs. The placemarks are updated to indicate if damaged and researchers can request the KML of the damaged and destroyed listing.

The newly discovered geoglyphs include some of the very largest recorded. I recorded Abuna Oval thanks to publication of Kalliola, R., & Pärssinen, M. 2024 - List of ancient geometric earthworks in southwestern Amazonia. Sixty-two of their 1,279 entries are now newly added geoglyphs in my amazon_geoglyphs.xls.

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Hundreds of Geoglifos Discovered in the Amazon

2010.01.20 - Geoglifos is the term applied in Brazil to geometric earthworks discovered after recent deforestation. Geoglyphs are not new in South American archaeology, but these are different—massive earthworks of tropical forest soil rather than desert surface alterations. The Amazon Geoglifos present geometric forms; circles, squares, ellipses, octagons, and more, with individual forms up to several hundred meters across. Some are connected by parallel walls. Their distribution spans hundreds of kilometers, and much of the area remains forested jungle. Some resemble geometric earthworks in the Ohio Valley.

Click images to view larger aerial imagery.

Geoglifos have been discovered in Google Earth by exploring areas with recent high-resolution imagery updates. (Click thumbnail images herein to view larger image files in a new window.) Recent Brazilian news videos on the ground and from small planes, embedded below, clearly illustrate the impressive scale, the massive amount of earth moved, and the unique monumental quality of this ancient cultural expression.

Earthworks preservationists, researchers, and recent archaeology news feeds called my attention to these constructs enough times to finally prompt online research. I was surprised by their numbers and scale. I quickly noticed many newly-discovered earthworks are already damaged. There seems to be no respect of or protection for the unique archaeological remains. Have efforts been made to preserve them? Do the forms go unnoticed on the ground in the jungle because of their large scale? The ancient human landscape has come to the attention of UNESCO, good news for conservationists while jungle deforestation marches apace. Apparently, archaeology survey needs to precede road building and vegetation clearing in this region, not follow on the deforestation.

Perhaps greater recognition of the signficance and scope of the Amazon Geoglifos discovery will protect them. With that goal in mind, here follows a collection of the current YouTube videos, placemark links, more images from Google Earth, readings, and online resource links:

O Mistério dos Geoglifos

May 25, 2013 - Quem desenhou sulcos tão profundos no solo amazônico,
e de forma tão precisa? Por que? Quando? E com que intenção?

Documentário - Na Trilha dos Geoglifos - 54:49 minutos

Oct 26, 2013 - Documentário de Marisa Dwir, sobre as grandes marcas no solo do
Estado do Acre. Esse documentário fala sobre a descoberta dos Geoglifos, as pesquisa
que estáo sendo realizadas, quais as áreas de pesquisas e como estáo sendo feitas.

Google Earth Placemarks
2011.01: amazon_geoglifos.kmz
2011.04 update: geoglifos_brazil.kmz

I'm posting a placemark file of the geoglyphs I could find. Recently local archaeologists thought, given the known distribution and the amount of the area deforested so far, only ten percent of the geoglifos were known. Some are visible in YouTube videos that are not yet seen on Google Earth. Hundreds exist and more will be visible and discovered as new areas of Google Earth update with hi-res images.

2014.02.02 - Updated Google Earth placemarks file with 240 geoglyphs, plus many ground lines. The new discoveries extend the area of geoglifos east, west, and south, including just across the border in Bolivia. Download brazil_geoglifos.kml. I seek additional placemarks and data files. Please GPS monuments you visit.

"... you found many we still didn't have. We have identified 410 geogliphs in Acre alone."
Dr. Denise Schaan (via e-mail) 2014.02.

Schaan, et.al. 2010 - Arqueologia da Amazonia Ocidental: Os Geoglifos do Acre
PDF - Ninety excellent aerial photographs.

Denise Schaan 2010 - Paisagens da Amazonia Ocidental
Our ability to locate geoglyphs increased significantly when Alceu Ranzi, Roberto Feres and Foster Brown discovered that they could use Google Earth, available for free on the internet, as a remote prospecting resource. In this way, undertaking systematic scans of satellite images, it was possible to quickly multiply the number of known structures. In 2005, 32 were known, in 2007 this number was already 150 and in 2010 we already have about 270 registered structures, but not all of them have yet been visited and named. Starting in 2007, with the support of the Government of the State of Acre, we obtained access to images from another satellite, Formosat, which has better coverage than Google and which made it possible to cover all areas without vegetation. Through satellite images, we also located geoglyphs in the south of Amazonas, in Bolivia, and in Rondonia.

Alceu Ranzi 2010 - Geoglifos: a descoberta e o potencial turistico
... I had the opportunity to participate, in 1977, in Acre, in the first stage of the PRONAPABA Project (National Program for Archeological Research in the Amazon Basin), under the coordination of Dr. Ondemar Dias and the participation of archaeologist Franklin Levy. On the second day..., the first geometric structure built in the shape of a circle, with a ditch and a wall, was located. The view at ground level was partial, although it is etched in the memory of the entire team. But in 1986, when I had the chance to see such a structure from above, I was really impressed. It was during a commercial flight between Porto Velho and Rio Branco. From there, I sought support from the Civil Cabinet of the Government of Acre. We got a plane to fly over, thanks to Prof. Geraldo Goncalo da Costa. Paleontologists Dr. Jonas Pereira de Souza Filho and Dr. Carl Frailey, biologist José Carlos Rodrigues dos Santos and photographer Agenor Mariano. The photos of this pioneering flyby were published in the August 15, 1986 edition of Jornal O Rio Branco, at the time the only newspaper in the Acre capital, and portrayed a monument-site, with a double semicircular format, later registered as Seu Chiquinho.

Reflections - Reflexões

An unusual moment presents itself in the Amazon. Unlike regions where we regret past destruction, this is a region where impending destruction can still be prevented. Will the current physical destruction to the earthworks stop or continue as roads intrude in the jungle and deforestation advances? Will ethnobotanists examine the botanical flora of the clearly-demarcated ancient sites before deforestation? Will any of the still-forested sites be preserved as they are today?

Aerial Photography Updates - Fotografia Aérea Atualizaçãos

2014.01.28 - Twenty new images of updated Google Earth aerial photography have been added to or linked from this page. Some older images now link to larger, updated imagery. Some of the largest geoglyphs are not yet seen in Google Earth, so check future updates.

In Google Earth, many geoglyph images updated since 2011, revealing new geoglyphs and providing higher resolution imagery of known geoglyphs. Detailed aerial photographs show how recent the deforestation of some of the earthworks is. They also reveal how fence lines add unwanted new erosion lines to the otherwise still pristine earthworks. Individual trees and even palm fronds are visible in the best resolution updates today, enabling better documentation and oversight of their conservation or destruction.

Some newly discovered in Google Earth geoglyphs have been surprising. Geoglifos are now visible much further to both the west in Acre and east in Rondonia. One is seen in Bolivia, making them an international phenomena. A great variety of geometry is presented. Several of the large monuments are grouped. One of the largest of the earthworks, the Bella Flor Geoglyph, measures 380 meters on one axis, surpassing the previous largest. The new database file presents their dimensions and categorizes the geometry.

Brazil Geoglifos 2014 Excel Database - brazil_geoglifos.xls
Brazil Geoglifos 2014 Google Earth Placemarks - brazil_geoglifos.kml
2015.04 updated imagery surveys - geoglyphs_2015.04.kml

2014.10.08 - Fifty-six new Amazon geoglyphs have been noted where Google Earth images were recently updated, including an area near Boa Vista, Amazonas rich in monuments and lines (image below). To get a better idea of the pattern the images create on the earth, I used the line tool to outline the visible earthworks. New geoglyphs placemarks file: https://www.jqjacobs.net/amazon/geoglyphs.kml, updates to the Excel and KML files with this data to follow.

2014.11.16 - Another Google Earth imagery update in Rondonia enabled survey of more geoglyphs. New placemarks, outlines, and lines are added to the most recent files linked above. Coordinates have been updated to uniformly reflect current imagery placements. Some site names and variables in the dataset have been edited. Currently, over 300 geoglyphs are placemarked.

Google Earth's Historical Imagery tool is quite useful in surveying the sites. The slider facilitates switching between all the different aerial images that have been posted for every location. In some cases, older views are not deforested or overgrown and uniformly green. Other images may reveal the earthworks clearly because the pastures are closely grazed during the dry season when vegetation colors vary. Switching between images also reveals how much placement has changed as newer images were added, illustrating why some coordinates have been updated.

Historical imagery also reveals earthwork destruction. I noticed bulldozing obliterating earthwork acrc16 (-10.0968 -67.6587) just before Sept. 2009, for the convenience of planting it seems. Plowing is impacting others. Bulldozing is used in deforestation, so many earthworks may disappear before images of them are even captured. As is typical of the "advance" of "civilization," we know not what we destroy and the destruction impedes ever knowing. Pages are being torn from the book of history written upon the earth. The earthworks are protected by laws, which apparently are either ignored or not enforced.

The virtual resources to appreciate this incredible cultural manifestation aid in preservartion efforts. As more and more geoglyphs become clearly visible in Google Earth, the immense and impressive scope of the Amazon geoglyphs becomes more apparent. We have a long way to go to understand what we are discovering. Hopefully, the Amazon geoglyphs will be one manifestation of the past that survives the present, or we may never know.

2016.02.16 - With all 2015 and 2016 surveys to date and data consolidation, the data files now include 440 geoglyphs. Excel and Google Earth files are updated, and archaeogeodesy.xls has all 2015 data.

After discovering the first geoglyph in Peru and several more in Bolivia, I renamed the files Amazon Geoglyphs. Included for comparison are several large geoglyphs in Beni, Bolivia. Also, compare the Kazakhstan geoglyphs.

Here are the latest data file versions:

Amazon Geoglyphs v2016.02.16 Excel Database - amazon_geoglyphs.xls
Amazon Geoglyphs v2016.02.16 Google Earth Placemarks - amazon_geoglyphs.kml

Clark L. Erickson 2015: Pre-Columbian Monumental Landscapes in the Bolivian Amazon

Space Archaeology in the Amazon, Beni, Bolivia

2017.02.07 - After catching up the Amazon Geoglyphs survey, I turned to the adjacent area to the south in Bolivia. Several areas with newly updated hi-res imagery in Google Earth had dense prehistoric occupation with earth moving cultural expressions. This Amazonian region, a vast, seasonally flooded savannah known as Llanos de Mojos, is particularly rich in archaeology. Elaborate causeway and canal networks and extensive raised agricultural fields are visible along with geometric earthworks and mounds. Survey results are placemarked in a new Google Earth KML file:

Google Earth KML Document - 734 KB - https://www.jqjacobs.net/amazon/bolivia.kml

Space archaeology has become easier over the last decade as more high resolution imagery is published. I can't keep up, but I'll keep trying. Already, more areas in Bolivia are updated and many more earthworks are visible, so I'll update this file later. Check the ArchaeoBlog for the latest news. Meanwhile, in the bolivia.kml zero in on the immense zanjas in southeast Mojos and their lunar major alignment.

Updates - Atualizaçãos

2019.01.31 - Currently, more than 500 geoglyphs are documented in both an Excel spreadsheet and Google Earth placemark files. The geoglyphs are placemarked, all except the smallest earthworks are outlined, plus visible ancient lines are highlighted.

2021.12.30 - Currently, I have placemarked and databased more than 1,100 ancient Amazonian earthworks, with over 1,050 geoglyphs and zanjas plus over 50 mound villages documented in both the Excel file and the KML placemarks file linked above. Almost all earthworks are outlined, along with highlighting of 1,000 lines, visible ancient roads and embankments. I've also added, to improve viewing the outlines and lines and to facilitate creating graphics, background overlay images with three color options, black, blueprint, and jungle green.

This first major update after nearly three years more than doubles the number of sites since then. In the past three years Google Earth satellite imagery updated in many areas and I began using other satellite image providers, especially for those areas still having poor resolution in Google Earth. I patiently waited ten years and relented to doing the extra work involved. Viewing more satellite images augments and upgrades the data, justifying the effort. I updated numerous coordinates, outlines, and lines, and added graphics, more research results, and academically published site names.

Some of the geoglyph placemark balloons now feature quotations with links to their sources, thus geolocating selected information. Below in this page the references table is updated and the table is also in a folder in the KML file.

2022.04.26 - Since the Dec. 30 update, I've researched local naming of sites and aerial photography. Several geoglyphs not easily spotted in satellite images were revealed. More geoglyphs are placemarked and outlined and more geoglyph placemark balloons feature referenced information and published locality names. Herein and in pertinent placemark balloons I've added more information about the history of discovery of the geoglyphs, a few more references, plus links to selected aerial photography. Both the KML and XLS files are updated.

2022.07.06 - Following on the Nature article of new LiDAR surveys in Llanos de Mojos, I decided to update the Beni, Bolivia KML. Surveying the past six years of Google Earth hi-res updates in the region added over 3,500 placemarks, doubling the number of visible earthworks.

Llanos de Mojos, Beni, Bolivia ancient earthworks; mounds, causeways, canals, weirs, raised fields.
View larger image - download 2.7 MB KML file - jqjacobs.net/amazon/bolivia.kml

2023.02.04 - One satellite image update in particular in Acrelandia clearly illustrates how different aerial satellite images produce different survey results and how important it is to examine as many satellite images as possible. The recent imagery updates also illustrate the optimal time in the annual vegetation and grazing cycle for satellite imagery to reveal the ancient earthworks and overcome a limitation of space archaeology in verdant regions. At the end of July the pastures are closely grazed and dry season vegetation variation is on display. Contrastingly, the nearby update with June 20, 2022 imagery around Placido de Castro did not reveal more than previous surveys. The new ../acrelandia_2022_survey.kml placemarks file illustrates how many additional earthworks were revealed in the survey area, perhaps better stated as revealing how many may remain hidden in so many other satellite images, the reason I am making this point and providing the KML. We will know the full extent of the archaeology once the region has complete lidar surveying, given of course, if the evidence is not plowed away. Too often resurvey also reveals illegal earthwork destruction in recent years.

2024.01.16 - Currently, more than 1,150 geoglyphs and zanjas, plus 60 mound villages are documented in both the Excel file and the KML placemarks file linked above. Both satellite imagery updates and recent publication of several databases contributed to the additions. One of the most significant additions in the last year is about forty aerial images of geoglyphs taken by Dr. Rob Walker using a drone. To sort to these placemarks and others with academic citations which geolocate research take note in the Google Earth Places menu of the balloons with background color.

Photo credit: Dr. Robert S. Walker

The KML file contains a surveys folder with subfolders sorted by years including 2024. I've also done some resurvey of newer satellite imagery from diverse providers in areas where Google Earth has yet to provide high resolution imagery. In Google Earth, opening the Historical Imagery tool may result in display of more recent imagery than the default display, albeit the most recent imagery may include clouds. Also, zooming in close can alter which imagery displays. Current centerpoints and outlines may reflect more recent imagery than the default display.

As the resolution of available satellite imagery improves, resurvey reveals and documents more geoglyphs and zanjas, albeit in some areas the returns are minimal for the amount of work involved. At the same time I am able to update placements and improve outlines so I continue to resurvey. The Excel file 'versions' worksheet is the best resouce to determine if you have the most recent updates. The source columns in the dataset worksheets reflect if an entry has been recently added as well as if updated with refined coordinates. Areas of low resolution imagery in Google Earth may reflect other sources.

2024.10.19 - Happy International Archaeology Day - Now 1,370 geoglyphs and 83 mound villages documented after recent satellite imagery updates and a dataset release by Risto Kalliola and Martti Pärssinen. New 2024 aerial photos by Dr. Walker are embedded in the KML placemarks. Recent deforestation revealed another octagon, now named Amazonas Octagon, of the same size as the destroyed and recently replowed Acre Octagon. Both express phi relationships to Newark Octagon in Ohio, as discussed in Newark Archaeogeodesy and in the updated Octagons KML file.

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Geoglyph News - Geoglifo Notícias

2024.10.19 - Acta Amazonica article Geography of ancient geometric earthworks and their builders in southwestern Amazonia published along with the dataset List of ancient geometric earthworks in southwestern Amazonia.

"... We used a review of existing and new data to map earthworks across 27,569 km2 of deforested areas in southwestern Amazonia using satellite imagery. We developed a conceptual basis for the classification of earthworks based on their structural characteristics using fuzzy sets. We recorded 1,279 structures with a distinctive core density zone. Most of the structures displayed geometric shapes, but they varied in construction accuracy. Geoglyphs accounted for 80% of all objects, with geographically variable shapes and enclosure areas. Other earthwork types included associated embankments, solitary embankments and mound sites. ...."

2024.09.25 - The Uncertain Future of Ancient Geoglyphs - Watch - 10:04
"... one archeologist (Antonia Barbosa, IPHAN) is fighting to protect ancient sites from Brazil's seemingly unstoppable agribusiness industry ....

2024.09.25 - Fazendeiros destroem antiga civilização na Amazônia - Peter Millard, Raeedah Wahid, Dado Galdieri para Bloomberg

"... os fazendeiros veem a terra como uma fonte de renda e as históricas estruturas geométricas no chão, conhecidas como geoglifos, estão no caminho. Pelo menos nove dos sítios antigos mais emblemáticos — alguns dos quais abrangem até 385 metros de largura e quase 5 metros de profundidade — já foram arados nos últimos anos. Isso está apagando as evidências de uma civilização ...."

"... farmers see the land as a source of income, and the historic geometric structures in the ground, known as geoglyphs, are in the way. At least nine of the most iconic ancient sites — some of which span up to 1,200 feet wide and nearly 16 feet deep — have been plowed over in recent years. That’s erasing evidence of a civilization ...."

2024.02.16 - 2021 book now online via academia.edu, Alceu Ranzi & Martti Parssinen: Amazonia: Os Geoglifos e a Civilizacao Aquiry featuring more than 75 aerial photographs.

Esta obra pode ser considerada a celebraçao de 20 anos dos mais completos registros fotograficos dos geoglifos do Acre. Quem estiver interessado nos detalhes pode procurar a ediçao do dia 16 de abril de 2000 dos jornais "A Gazeta" e "A Tribuna", ambos da cidade de Rio Branco, capital do Acre. Foi a partir dessa data que os geoglifos do Acre passaram a ocupar espaço na imprensa nacional e internacional. Na epoca, anterior ao mundo digital, as fotografias foram obtidas, reveladas e copiadas em papel, pelo fotografo profissional Edison Caetano.

2020.08.08 - Sítios arqueológicos são aterrados em fazenda de presidente da Federação da Agricultura do Acre. The Instituto do Patrimônio Histórico e Artístico Nacional called the Federal Public Ministry and the Federal Justice after discovering that archaeological sites, where three geoglyphs are located, at Fazenda Crixa II, in the city of Capixaba, in the interior of Acre, were leveled during the process grain planting. Geoglyphs are protected by federal law.

2019.10.31 - Recent academic publication now online, plus article links:

A la sombra de los Andes. Arquitectura monumental en los Llanos de Mojos 2018 Carla Jaimes Betancourt and Heiko Prümers

Why Some Amazonian Societies Survived and Others Perished amid Pre-Columbian Droughts, Debbie Ponchner, Scientific American

Ancient Amazonian societies managed the forest intensively but sustainably—here’s what we can learn from them

2018.11.12 - Globo has an excellent video with their news report With a unanimous decision, geoglifo in Rio Branco is the first to be registered by IPHAN on the UNESCO World Heritage Tentative List. IPHAN's president Kátia Bogéa pointed out "It is something extremely relevant and important about the trajectory of human beings on Earth...."

Rio Branco - 09/11/2018. Com decisão unânime, geoglifo em Rio Branco é o primeiro a ser tombado pelo Iphan. Os 22 membros do Conselho Consultivo votaram a favor do tombamento. Sítio Arqueológico Jacó Sá possui dois geoglifos e fica a 50 quilômetros de Rio Branco. ......

2018.03.27 - An excellent Nature article published online today, Pre-Columbian earth-builders settled along the entire southern rim of the Amazon, reports on a little studied section of the Southern Rim of the Amazon (SRA):

"... the discovery of Pre-Columbian ditched enclosures in the Tapajós headwaters. The results show that an 1800 km stretch of southern Amazonia was occupied by earth-building cultures...."

"The possible geographical continuity of late Pre-Columbian earth building cultures across all southern Amazonia has been envisaged for nearly a decade; however, archaeological evidence of such long-range connections remained elusive. The results of our survey in the Tapajós headwaters confirm that ditched enclosures are found over an 1800 km east–west belt along the SRA. The expansion in earthwork construction and the peak of occupation at most sites—both in the eastern and western extremes of the SRA—occurred between Cal AD 1250 and 1500. During this time, the whole SRA was settled by dense populations...." (emphasis added)

2015.02.16 - A BBC article Brazil Amazon: Drone to scan for ancient Amazonia reports a $1.9 million grant from the European Research Council to laser scan for Amazon geoglyphs. This is great news for geoglyph research and hopefully for preservation of some grand, historically-unaltered earthworks and their ecology:

... A drone will be sent up with a laser instrument to peer through the canopy for earthworks...

This vehicle's lidar instrument should reveal how many more geoglyphs remain hidden beneath still-canopied regions of Amazonia. ...

No-one is really quite sure what these earthen circles, squares and lines represent. ... "It’s a hot debate right now in New World archaeology," said Dr Jose Iriarte...

Drone varrerá Amazônia em busca de civilizações antigas Jonathan Amos, Correspondente de Ciência da BBC News, de San Jose, 16 fevereiro 2015.

... Dependendo dos dados obtidos, eles também podem ser usados para a elaboração de políticas de uso sustentável da floresta.

Mas a questão mais importante é tentar compreender a escala e as atividades das populações que viveram na Amazônia no final do período antes da chegada dos europeus à América, ou seja, os últimos 3 mil anos antes de 1490....

2015.02.23 - Another major article today, Drones to scan for evidence of ancient civilizations in Amazonia.

Among other objectives, (Dr. Jose) Iriarte hopes to test this idea of large, complex and hierarchical societies in the Amazon, known as the “cultural parkland hypothesis’, by conducting an intensive study of four distinct regions across the Amazon, implementing a battery of state-of-the-art techniques from the social and natural sciences, including archaeology, archaeobotany, ethnohistory, and paleoecology, in conjunction with remote sensing technology. ...

Videos and Graphics - Vídeos e Imagens

One of the largest works visible in Google Earth is the Aeropuerto site near Rio Branco, Acre, Brazil.
rio branco geoglyph
Click image for larger version. Images below link to large files with updated, high resolution imagery.

Geoglifos Amazônicos

Sept. 2008 - Documentario Exibido no Fantastico, sobre Geoglifos

Geoglifos em Acrelândia

April 2008

Geoglifo

Sept. 2006, Equipe da TBS e o palentólogo Alceu Ranzi
percorrem trecho de um geoglifo da Amazônia.

Geoglyph Readings - Geoglifo Leituras

National Geo 2010: "Lost" Amazon Complex Found; Shapes Seen by Satellite

The so-called 'crop circles' of Santa Teresinha are seen in a great photograph. "Satellite images ... have revealed more than 200 geometric earthworks spanning a distance greater than 155 miles (250 kilometers) ... uplands sites appear to have been home to as many as 60,000 people."

Historia: National Geographic 2017 - Photo Gallery - La deforestación amazónica deja al descubierto los antiguos geoglifos de los indígenas
... La deforestación moderna ha permitido descubrir más de 450 geoglifos amazónicos, que ocupan una superficie de unos 13.000 km2, en el estado de Acre ....

"It's an ill wind that blows nobody any good. The combination of land cleared of its rainforest for grazing and satellite survey have revealed a sophisticated pre-Columbian monument-building society in the upper Amazon Basin on the east side of the Andes. This hitherto unknown people constructed earthworks of precise geometric plan connected by straight orthogonal roads. Introducing us to this new civilisation, the authors show that the 'geoglyph culture' stretches over a region more than 250km across, and exploits both the floodplains and the uplands. They also suggest that we have so far seen no more than a tenth of it."
— Pre-Columbian geometric earthworks in the upper Purús: a complex society in western Amazonia Martti Pärssinen, Denise Schaan and Alceu Ranzi, 2009 Antiquity 83(322):1084-1095.

"GEOGLIFOS O que são? Geoglifos são vestígios arqueológicos representados por desenhos geométricos (linhas, quadrados, círculos, octógonos, hexágonos etc...), zoomorfos (animais) ou antropomorfos (formas humanas), de grandes dimensões e elaborados sobre o solo, que podem ser totalmente e melhor observados se vistos do alto, em especial, através de sobrevôo."
— geoglifos.com.br | links page

Internet Software Programs Aid in Search for Amazonian Geoglyphs, Alceu Ranzi, Roberto Feres, Foster Brown EOS Vol. 88, No. 21, 22 May 2007. - The Web-based Google Earth software program recently has incorporated high-resolution satellite imagery that facilitates the search for landscape expressions of past civilizations that we call geoglyphs. Since 2000, about 40 such geoglyphs have been observed in overflights above recently deforested pastures of southwestern Amazonia in eastern Acre State, Brazil. These geoglyphs typically are circular or rectangular, on the scale of 100 meters or more, with bordering trenches 1-3 meters deep (Figure 1). Carbon-14 dating of charcoal associated with these geoglyphs indicates ages between 2500 and 1000 years B.P.

"Until the past year, high-resolution Ikonos and QuickBird imagery was too expensive for local researchers to use in surveys for geoglyphs. The incorporation of such imagery by Google Earth for extensive stretches in Amazonia has permitted researchers to search for geoglyphs in eastern Acre. Figure 2 shows how preliminary data analysis can be done with high-resolution satellite imagery to determine the areal density and distribution of geoglyphs. In this transect, 39 potential geoglyphs were observed in an examination of the imagery. Through fieldwork and overflights during the past three decades, only nine geoglyphs had been discovered in the area of the transect."

Written on the land Amazonian Geoglyphs number in the thousands and are truly spectacular, let's look at the sources ... "Ring ditch sites in Acre and the Bolivian Amazon, described as geoglyphs because of their impressive patterns (circular, oval, octagon, square, rectangle, and D-shapes), appear to be more ceremonial than residential or defensive." (Martti Parssinen, Denise Schaan & Alceu Ranzi Pre-Columbian geometric earthworks in the upper Purus: a complex society in western Amazonia)

"Ring ditch sites are reported in the Bolivian Amazon (Figure 11.5), Matto Grosso, Acre, and Upper Xingu River regions (Erickson 2002; Heckenberger 2005; Parssinen et al. 2003; Ranzi and Aguiar 2004). These sites consist of a closed or U-shaped ditched enclosure or multiple ditches. Heckenberger (2005) describes numerous sites with large open plazas and radial roads marked by earthen berms extending through residential sectors enclosed by deep semi-circular moat-like ditches and embankments." ...
"Historical ecologists respond that ignoring the complex human history of environments in Amazonia would be unwise. A vast indigenous knowledge spanning hundreds of generations about the creation, transformation, and management of environments is physically embedded in the landscape, encoded in the distribution and availability of plant and animal species, documented in historical and ethnographic accounts, and in some cases, still practiced by native Amazonians."Amazonia: The Historical Ecology of a Domesticated Landscape

Feições geomorfológicas e solos nos locais em que foram construídos os geoglifos no estado do Acre - Brasil Full-text Chapter Sep 2015

References - Referencias

References and readings in table below updated 2025.07.

Articles by prominent researchers working in the geoglyphs region. The linked articles provide further references. Some articles are quoted and cited in the placemarks to geolocate relevant information.

Arnold and Prettol 1988 - Field Reports: Aboriginal Earthworks near the Mouth of the Beni, Bolivia

Balee 2014 - Florestas Antrópicas No Acre: Inventário Florestal No Geoglifo Três Vertentes, Acrelândia

Barbosa 2014 - Análise Espacial dos Sítios Monumentais do Leste da Amazônia Ocidental

Carson 2014 - Pre-Columbian land use and human impact in the Bolivian Amazon

de Souza et.al. 2018 - Pre-Columbian earth-builders settled along the entire southern rim of the Amazon

Denevan 1966 - The Aboriginal Cultural Geography of the Llanos de Mojos of Bolivia. In Ibero-Americana 48. Berkeley: University of California Press.

Denevan 1992 - The Pristine Myth: The Landscape of the Americas in 1492 in Annals of the Association of American Geographers 82(3): 369-385.

Denevan 2001 - Cultivated Landscapes of Native Amazonia and the Andes. Oxford University Press.

Diez Castillo et.al. 2017 - Preliminary results of the 2017 season in the Amazonian earthen structures known as geoglyphs

Erickson 2000 - An Artificial Landscape-Scale Fishery in the Bolivian Amazon

Erickson 2010 - The Transformation of Environment Into Landscape: The Historical Ecology of Monumental Earthwork Construction in the Bolivian Amazon

Erickson 2011 - Agency, Causeways, Canals, and the Landscapes of Everyday Life in the Bolivian Amazon

Erickson 2018 - Diversity of Pre-colonial Earthworks in the Brazilian State of Acre, Southwestern Amazonia

Erickson and Walker 2009 - Precolumbian Causeways and Canals as Landesque Capital

Erickson, et.al. 2008 - Zanjas Circundantes: Obras de Tierra Monumentales de Baures en la Amazonia Bolivia

Iriarte et.al. 2020 - Geometry by Design: Contribution of Lidar to the Understanding of Settlement Patterns of the Mound Villages in SW Amazonia

Iriarte et.al. 2021 - Refining the Chronology and Occupation Dynamics of the Mound Villages of South-Eastern Acre, Brazil

Kalliola et.al. 2024 - Geography of ancient geometric earthworks and their builders in southwestern Amazonia

Kalliola, R., & Pärssinen, M. 2024 - List of ancient geometric earthworks in southwestern Amazonia.

Langstroth 1996 - Forest Islands in an Amazonian Savanna of Northeastern Bolivia

Lombardo 2010 - Raised Fields in the Bolivian Amazonia: a prehistoric green revolution or a Floodrisk mitigation strategy?

Lombardo 2010 - Pre-Columbian human occupation patterns in the eastern plains of the Llanos de Moxos, Bolivian Amazonia

Lombardo 2010 - Raised Fields of Northwestern Bolivia: a GIS based analysis

Lombardo 2011 - Eco-archaeological regions in the Bolivian Amazon: Linking pre-Columbian earthworks and environmental diversity

Lombardo 2013 - Early and Middle Holocene Hunter-Gatherer Occupations in Western Amazonia: The Hidden Shell Middens

Lombardo 2014 - Soil properties and pre-Columbian settlement patterns in the Monumental Mounds Region of the Llanos de Moxos, Bolivian Amazon

Lombardo 2014 - Neotectonics, flooding patterns and landscape evolution in southern Amazonia

Mann 2008 - Ancient Earthmovers of the Amazon

Parssinen 2021 - Tequinho Geoglyph Site and Early Polychrome Horizon BC 500/300 - AD 300/500 in the Brazilian State of Acre

Parssinen et.al. 2024 - Zanjas circundantes en el extremo norte de Bolivia (Pando y Beni) y sus relaciones con los llamados Geoglifos de Acre

Parssinen et.al. 2024 - Geography of ancient geometric earthworks and their builders in southwestern Amazonia

Parssinen et.al. 2015 - Pre-Columbian Geometric Earthworks in the Upper Purus: A Complex Society in Western Amazonia

Parssinen et.al. 2015 - The geoglyph sites of Acre, Brazil: 10 000-year-old land-use practices and climate change in Amazonia

Prümers 2013 - Volver a los sitios - el Proyecto Boliviano-Aleman en Mojos

Prümers 2014 - Sitios prehispanicos con zanjas en Bella Vista, Provincia Itenez, Bolivia

Prümers and Betancourt 2014 - 100 anos de investigacion arqueologica en los Llanos de Mojos

Rampanelli 2016 - Las estructuras de tierra delimitadas por zanjas en la Amazonía Occidental

Ranzi 2003 - Geoglifos: Patrimônio Cultural do Acre

Ranzi et.al. 2007 - Internet Software Programs Aid in Search for Amazonian Geoglyphs

Saunaluoma 2010 - Pre-Columbian earthworks in the Riberalta region of the Bolivian Amazon

Saunaluoma 2012 - Geometric Earthworks in the State of Acre, Brazil: Excavations at the Fazenda Atlantica and Quinaua Sites Latin American Antiquity 23(4).

Saunaluoma 2014 - Os sítios pré-colombianos com estruturas de terra na região de fronteira entre o Acre, Brasil, e Riberalta, Bolívia, Amazónia sul-ocidental

Saunaluoma and Parssinen 2015 - Subsistence practices among earthwork builders: Phytolith evidence from archaeological sites in the southwest Amazonian interfluves

Saunaluoma and Schaan 2012 - Monumentality in Western Amazonian formative societies: geometric ditched enclosures in the Brazilian state of Acre

Saunaluoma et.al. 2018 - Diversity of Pre-colonial Earthworks in the Brazilian State of Acre, Southwestern Amazonia

Saunaluoma et.el. 2019 - UAV survey at archaeological earthwork sites in the Brazilian state of Acre, southwestern Amazonia

Saunaluoma et.el. 2020 - Patterned Villagescapes and Road Networks in Ancient Southwestern Amazonia

Schaan, et.al. 2007 - Geoglifos da Amazônia Ocidental: Evidência de Complexidade Social entre Povos da Terra Firme

Schaan, et.al. 2012 - New radiometric dates for precolumbian (2000-700 B.P.) earthworks in western Amazonia, Brazil

Virtanen & Saunaluoma 2017 - Visualization and Movement as Configurations of Human–Nonhuman Engagements: Precolonial Geometric Earthwork Landscapes of the Upper Purus, Brazil

Walker 2008 - Llanos de Mojos in William Isbell and Helaine Silverman, eds., South American Archaeology. New York: Kluwer, 927-940.

Walker 2008 - Pre-Columbian Ring Ditches along the Yacuma and Rapulo Rivers, Beni, Bolivia: A Preliminary Review

Watling et.al. 2017 - Impact of pre-Columbian "geoglyph" builders on Amazonian forests

Video - Penn Museum 2014 - Great Wonders: The Monumental Geoglyphs of Amazonia

Video - Brown University 2015 - Pre-Columbian Monumental Landscapes in the Bolivian Amazon

Video - University of Chicago 2012 - Culture amidst the Pristine: The Anthropogenic Forests of the Bolivian Amazon

Boa Vista, Amazonas, Brazil. View a larger version. Download a 2560 pixel deskpicture.

More Readings - Mais Leituras

You can visually explore the earthworks, the deforestation, and expanses of forested jungle on the virtual globe. Visit http://earth.google.com and Google Earth Community for more information about Google Earth. I will add content below as news, publications, and good photography links develop.

Ondemar F. Dias Jr. and Eliana T. Carvalho 1978 As Estruturas de Terra na Arqueologia do Acre Boletim do Instituto de Arqueologia Brasileira

"... Em 1976, teve início o Programa Nacional de Pesquisas Arqueológicas na Bacia Amazônica... No primeiro sítio localizado por nós em 1977, próximo à cidade de Rio Branco, pudemos constatar a existência de uma estrutura circular em forma de trincheira, com um pequeno acúmulo de terra em forma de muro na zona externa do círculo... representam um interessante e emocionante vestígio dos antigos povos indígenas que habitaram aquela parte da Amazônia."

Ciência anuncia 250 geoglifos descobertos no Acre (old link) - 25 de julho de 2009 - Os pesquisadores Alceu Ranzi e Denise Schaan anunciaram nesta sexta-feira, 24, a identificação de vinte novos geoglifos no Vale do Acre, elevando para 250 o número de estrutura catalogadas ... "Teremos novas escavações em 2010", informou Schaan ... o grupo de pesquisa ... "Geoglifos da Amazônia Ocidental" vem desenvolvendo desde 2005 pesquisas intensivas sobre os geoglifos no Estado, com o objetivo de fazer um amplo levantamento dos geoglifos na parte Leste do Acre. Os geoglifos fazem parte de uma lista do Instituto Nacional de Patrimônio Histórico e Artístico Nacional (Iphan) para recomendar à Organização das Nações Unidas para a Educação, Ciência e Cultura (Unesco) ...

Arqueologia: novas descobertas elevam para 255 os geoglifos do Acre (old link) - julho 27, 2009 - ... um grupo de pesquisadores já identificou e catalogou a existência de 255 geoglifos na parte leste do Acre ... Os geoglifos são figuras formadas por valetas com largura média de 11 metros, tendo cada valeta de 1 a 4 metros de profundidade. A técnica construtiva inclui muretas de 6 a 8 metros com meio metro de altura. As figuram chegam a medir em média de 100 a 200 metros. Eles possuem, ainda, caminhos com 20 metros de largura ...

Abril 10, 2009 (old link). Geoglifos do Acre podem ser reconhecidos pela Unesco como Patrimônio da Humanidade no Brasil. "Os geoglifos do Acre foram incluídos pelo Instituto do Patrimônio Histórico e Artístico Nacional (IPHAN) numa lista indicativa de bens passíveis de ser declarados pela Unesco como Patrimônio da Humanidade no Brasil."

There is no substitute for great aerial photography to appreciate the monumentality and massive efforts involved in creating the geoglyphs. Check out this 2017 National Geographic article:
La deforestación amazónica deja al descubierto los antiguos geoglifos de los indígenas

Geoglifos - 26 aerial photos by Edison Caetano

Amazon explorers uncover signs of a real El Dorado by Rory Carroll, "It is the legend that drew legions of explorers and adventurers to their deaths: an ancient empire of citadels and treasure hidden deep in the Amazon jungle." ... "... only now, as satellite imagery and felling reveal sites ... the scale of the settlements is becoming clear. Some anthropologists say the feat, requiring sophisticated engineering, canals and roads, rivals Egypt's pyramids."

www.geoglifos.com.br/ - criado pelo paleontólogo Alceu Ranzi - fotos e informações podem ser obtidas - Geoglifos do Acre. More information and photos on the Geoglyphs of Acre site. Hay mas informacion y fotos en el sitio Geoglifos de Acre. Fotos/photos.

Lombardo, Umberto and Heiko Prümers 2010 - Pre-Columbian human occupation patterns in the eastern plains of the Llanos de Moxos, Bolivian Amazonia, Journal of Archaeological Science 37:1875-1885.

"While researchers piece together the Amazon’s ecological history, mystery still shrouds the origins of the geoglyphs and the people who made them. So far, 290 such earthworks have been found in Acre, along with about 70 others in Bolivia and 30 in the Brazilian states of Amazonas and Rondônia ... Denise Schaan, an archaeologist at the Federal University of Pará in Brazil who now leads research on the geoglyphs, said radiocarbon testing indicated that they were built 1,000 to 2,000 years ago, and might have been rebuilt several times during that period... For Brazil’s scientists and researchers, Ms. Schaan said, the earthworks are “one of the most important discoveries of our time.” But the repopulation of this part of the Amazon threatens the survival of the geoglyphs, after being hidden for centuries. " NY Times Jan. 14, 2012

"The forested western Amazon was once thought barren of complex human culture. But researchers are now uncovering enigmatic earthworks left by large, organized societies that once lived and farmed here." Ancient Earthmovers of the Amazon C. C. Mann 2008.

"The unexpected discovery of immense geometrically patterned earthworks called "geogphyhs" among the terra firme rainforests of western Amazonia is radically changing our notion of past human societies in this region of the Amazon. Over 300 of these spectacular geometric earthworks have been found across eastern Acre state, Brazil." The Geoglyphs site has a photo gallery.

Sacred Geographies of Ancient Amazonia: Historical Ecology of Social Complexity
Denise P Schaan 2011. The legendary El Dorado—the city of gold—remains a mere legend, but astonishing new discoveries are revealing a major civilization in ancient Amazonia that was more complex than anyone previously dreamed. Scholars have long insisted that the Amazonian ecosystem placed severe limits on the size and complexity of its ancient cultures, but leading researcher Denise Schaan reverses that view, synthesizing exciting new evidence of large-scale land and resource management to tell a new history of indigenous Amazonia. Schaan also engages fundamental debates about the development of social complexity and the importance of ancient Amazonia from a global perspective. This innovative, interdisciplinary book is a major contribution to the study of human-environment relations, social complexity, and past and present indigenous societies.

Professora Denise Schaan fala sobre os geoglifos da Amazônia
Portuguese radio: http://www.youtube.com/watch?v=kYSivFWklWo

Good aerial photography with place names: Tecnologia faz descoberta de geoglifos na Amazônia saltar 1.000% em 11 anos 13/10/2012. Em junho deste ano, pesquisadores identificaram 18 novas formas geométricas no Amazonas, antes escondidas pela floresta.
"RIO BRANCO - Descobertos no Acre, os geoglifos ganharam repercussão nacional e internacional em 1977. Em entrevista ao portalamazonia.com, a atual responsável pelos estudos, pesquisadora Joanna Troufflard, conta que a identificação de novas formas geométricas na Amazônia se intensificou a partir de 2005, por meio de imagens de satélite. Até 2001, eram conhecidos apenas 24. O número saltou para 120 em 2005, e hoje são cerca de 300 somente no Acre. ..."

Long Before Making Enigmatic Earthworks, People Reshaped Brazil’s Rain Forest reports on Jenny Watling recent research and has two great aerial images. Good science writing by Joanna Klein for the New York Times.
Covering Watling's research, Charlie Wood writes, "Mysterious earthworks in Western Brazil known as 'geoglyphs' might hold historical lessons about sustainable management of the Amazon, and forests in general." Do these ancient 'geoglyphs' hold a secret to preserving the Amazon?

Geoglifos da Amazônia Ocidental: Evidência de Complexidade Social entre Povos da Terra Firme 2007
A arqueologia do Estado do Acre tor-nou-se conhecida a partir de 1977 comas investigações realizadas pelo Programa Nacional de Pesquisas Arqueológicasna Bacia Amazônica - PRONAPABA. Ondemar Ferreira Dias Jr. e Franklin Levy, do Instituto de Arqueologia Brasileira, foram os primeiros a identificar e registrar sítios arqueológicos na região, cadastrando, até 1980, 70 sítios ...

Mais de 800 geoglifos esperam por pesquisas na Amazonia. 17/02/2020
Um total de 818 geoglifos na Amazônia Internacional esperam para serem estudados. Os desenhos geométricos feitos na terra precisam de mais pesquisas para terem sua real função definida. Segundo a historiadora e arqueó - óloga do Instituto do Patrimônio Histórico do Acre, Ivandra Rampanelli, em sua tese de doutorado, 523 estão no Acre, 144 no Amazonas, 71 em Rondônia e 80 na Bolívia.

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia - October 2023
"... We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state. ..."
The estimate published by these 230 authors may be very optimistic given what is currently known about the distribution limits of geoglyphs. Their published database was useful, adding 22 geoglyphs to my dataset. However, I also noted over 20 percent of their 893 records in the SW Amazon area were duplicates or not geoglyph sites.

Atacama Desert Art and Archaeology
placemarks, geoglyphs and more: atacama.kml

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