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Amazonian Geoglyphs May Be Remnants of a Lost Civilization

The current (and some would say tragic) deforestation of the Amazonian rainforest has given archeologists a small – and some would say ‘ironic’ – benefit. As the trees disappear, evidence appears of what may be a lost civilization that lived in the area 4,000 years ago and conducted the first human alteration of the forest, creating what are now being called (as all other geoglyphs must now be called) Amazonian Stonehenges.

The fact that these sites lay hidden for centuries beneath mature rainforest really challenges the idea that Amazonian forests are ‘pristine ecosystems.

Jennifer Watling, post-doctoral researcher at the Museum of Archaeology and Ethnography, University of São Paulo, is referring to over 450 large geometrical earthworks discovered in in Acre state in the western part of the Brazilian Amazon. Archeologists were able to determine what the structures aren’t – they’re not villages because they have few artifacts and they’re not fortresses because they’re arranged wrong – but they’re at a loss to identify what purpose the geoglyphs actually served.

As reported in their study in Proceedings of the National Academy of Sciences, one thing the archeologists do know is that the geoglyphs were not the first alterations made by humans on the rainforest. Five-foot-deep (1.5 m) holes dug at the Jaco Sá and Fazenda Colorada geoglyph sites gave a 6,000 year history of these areas. The first interesting find was that bamboo resiliently survived as the primary plant in the area for quite a while through various climate changes. There was no evidence of burning until 4,000 years ago when the first humans appeared and cleared areas to grow palms and other more useful and valuable (to humans) trees.

Sometime around 2,000 years ago, these unknown indigenous people cleared the forest again for a different reason – to create the mysterious earthworks geoglyphs. These were first discovered in the 1980s and cover 13,000 square km (500 square miles). The glyphs are mostly rectangular or circular, leading to early conclusions that they were for living or defense.

While some evidence of food is found nearby, the predominant artifact found in and around the geoglyphs – especially at what appear to be entrances – is smashed and broken pottery. Watling thinks this may indicate the area was a marketplace during harvest season. Whatever the glyphs were used for, the soil samples show that all human activity in the area ended around 650 years ago. Hmm, what happened in South America around that time?

Fortunately, the rainforest protected the glyphs and their mysterious history until recently. The fact that research proves humans have been clearing the forest for centuries does not justify today’s destruction, says Watling.

It should instead serve to highlight the ingenuity of past subsistence regimes that did not lead to forest degradation and the importance of indigenous knowledge for finding more sustainable land-use alternatives.

What are the odds of THAT happening?


Paul Seaburn is the editor at Mysterious Universe and its most prolific writer. He’s written for TV shows such as "The Tonight Show", "Politically Incorrect" and an award-winning children’s program. He's been published in “The New York Times" and "Huffington Post” and has co-authored numerous collections of trivia, puzzles and humor. His “What in the World!” podcast is a fun look at the latest weird and paranormal news, strange sports stories and odd trivia. Paul likes to add a bit of humor to each MU post he crafts. After all, the mysterious doesn't always have to be serious.
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