a heavily populated pre-European contact Amazon basin.

Raised some controversy, of course. But I had no idea these recent discoveries had occurred until I heard some discussion of this book on NPR (IIRC).

Hundreds of mysterious ancient earthworks found in the Amazon

Melissa Breyer (@MelissaBreyer)
Science / Conservation
February 7, 2017





© Jenny Watling


Deforestation has revealed the large geometrical geoglyphs built over 2,000 years ago – their discovery holds valuable lessons for today.

The Amazon rainforest is so rich, so dense with trees, that the forest floor is constantly in the dark. The vegetation hides many things, from isolated indigenous communities who have yet to have contact with the outside world to, as has just been discovered, massive earthworks built over 2,000 years ago.

The ditched enclosures, in Acre state in the western Brazilian Amazon, were discovered during research by Jennifer Watling, currently a post-doctoral researcher at the Museum of Archaeology and Ethnography, University of São Paulo. Hidden for centuries by trees, modern deforestation revealed the 450+ large geometrical geoglyphs.

The earthworks are spread out over roughly 5,000 square miles. And what they were used for is not entirely understood. Few artifacts were found during excavation, leading experts to discount the idea that they could have been villages. Their layout doesn’t indicate they would have been used for defense. They were likely only used on occasion, maybe as ritual gathering spots – but no one can say for sure.

More:
http://www.treehugger.com/conservation/hundreds-mysterious-ancient-earthworks-found-amazon.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+treehuggersite+%28Treehugger%29

Mysterious Stonehenge-like 'geoglyphs' found in Amazon rainforest point to ancient human settlements





Scientists have found ancient mysterious earthworks resembling the circular pattern of Stonehenge in the Amazonian rainforest that suggest humans may have lived in the region centuries earlier than thought.

Researchers from Universities of Exeter and Reading in the UK, and the University of Sao Paulo in Brazil, discovered more than 450 large geometrical ‘geoglyphs’ that are believed to be at least 2,000 years old.

The earthworks remained hidden amongst the rainforest trees – in the ditched enclosures in Acre state of the western Brazilian Amazon taking up roughly 13,000 km square of space – until modern deforestation allowed the discovery.

The findings suggest indigenous people lived in the Amazon long before European people arrived in the region.



More:
http://www.breakingnews.ie/world/mysterious-stonehenge-like-geoglyphs-found-in-amazon-rainforest-point-to-ancient-human-settlements-776163.html

MYSTERIOUS GEOGLYPHS CAN TEACH US ABOUT THE AMAZON'S PAST—AND ITS WORRISOME FUTURE
ENORMOUS SHAPES ETCHED ONTO THE EARTH
By Rachel Feltman 7 hours ago





Modern deforestation has revealed more than 450 of these strange shapes



We know that the forests of the Amazon have a long history of human interference. Scientists have been studying the region's ancient geoglyphs—large designs traced into the ground with rocks and other debris—since the 1960s, when deforestation by cattle ranchers first revealed the stunning shapes. Because the geoglyphs only appeared once forests had burned away, it follows that the ancient artists must have burned their own trees to the ground to build them.

But according to new research, this knowledge shouldn't give us hope that it will be easy to bounce back from modern deforestation—which, in the past half a century, has destroyed around 20 percent of the Amazon rain forest.

The geoglyphs have been cited as a sign that Amazonian forests aren't meant to be kept "pristine". Some forests have evolved to occasionally burn. If the Amazon rain forest has been influenced by humans for thousands of years—and grew back just fine when swaths sat unoccupied for a few centuries—then is it right to say we should leave it alone entirely?

New findings suggest that indigenous farmers cleared their surroundings on a much, much smaller scale than today's cattle ranchers. So while the area might not be adapted to total seclusion, we should still worry that our excessive meddling will kill the forest for good.

More:
http://www.popsci.com/mysterious-ancient-geoglyphs-can-teach-about-amazons-past-and-its-worrisome-future?dom=rss-default&src=syn

These designs in the Amazon rainforest were created 2,000 years ago -- and archaeologists are still baffled by them
GENE KIM, JESSICA ORWIG
FEB 9, 2017, 8:13 AM



- Video at link -

The Amazon isn’t as pristine as you might think. Turns out, humans have been changing its landscape for thousands of years.

This suggests that some of the Amazon we know today was largely influenced by ancient human activity — and one of the latest pieces of evidence that support this idea comes from mysterious designs in the Brazilian state Acre.

Hundreds of these man-made designs popped up in the 1980s, but archaeologists still aren’t sure what purpose they served. But, a new study, published in the Proceedings of the National Academy of Sciences, revealed that samples collected at a few of the sites contained evidence of charcoal — a byproduct of fire.

Most likely, ancient humans were setting fires in the Amazon as an early form of deforestation.

More:
http://www.businessinsider.com.au/amazon-rainforest-mysterious-geoglyphs-2017-2

Lost Worlds of South America. I am only about a 1/3 into it, but the lecturer is arguing for early habitation of the Amazon, and I think he will argue that the Peru located advanced civilizations had considerable cultural influence from that region (the Fanged God - a man turning into a jaguar).

Great Courses was running a free month long intro offer.

https://www.thegreatcoursesplus.com/home

Also if you have Hoopla through your local library, then they have a bunch of the courses as well.

The Chinchorro mummies are far older than the geoglyphs recently found in the Amazon - human prepared mummies are as old as 5050 BC while natural mummies found in Chile's Atacama Desert are as old as 7000 BC.

For population pressures to have forced people to move into such inhospitable areas as the Chilean deserts, much of the rest of the continent may have been well occupied.

That argument could be countered by the theory that the original exploration of the Americas was along the coasts from Alaska to Chile but there are other settlements in South America that are far older than the 2000 years cited for the age of these geoglyphs.

14,000-year-old campsite in Argentina adds to an archaeological mystery

On the other hand, the long studied terra preta (bio-char soils) date to the same period as these geoglyphs and have been associated with significant terraforming that created causeways connecting communities: