Soil and Satellites Are Telling a New Story About Ancient Civilizations in the Amazon

With new technologies, scientists are looking for clues in manmade “terra preta.”
BY KATARINA ZIMMER MARCH 20, 2018



The Amazon may not be as pristine as it looks. Rainforest in Manú National Park, Peru. KATARINA ZIMMER

WHEN FRANCISCO DE ORELLANA, A Spanish conquistador, paddled through the Amazon in 1541, he did not find El Dorado, the fabled kingdom of gold he had been looking for. But he did report to have found civilization: large villages and farms sprawled along the rivers, and even massive cities in the distance.

However, when later explorers and missionaries returned to the same spots centuries later, they found nothing but wild tangles of vegetation. Orellana’s reports were dismissed as bogus when scientists chimed in. Large settlements, in the Amazon rainforest? That would be impossible, they said, for the same reason that it’s still impossible to occupy the Amazon today. Although the forests have rich, wild plant life, the soils alone are too poor in nutrients to support long-term cultivation of agricultural crops.

“But what archaeologists have been seeing in the last 30 years is that, quite the contrary—the Amazon has been densely occupied in the past,” says Eduardo Neves, a Brazilian archaeologist.

One surprise has been the discovery of something that is, in some ways, much more valuable than the gold the Spanish had originally been looking for: terra preta de índio, “dark earth of the Indian,” a blend of charcoal and very nutrient-rich earth that is dark in color, and extraordinarily fertile—in stark contrast to the surrounding orange-yellowish, unproductive earth.

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https://www.atlasobscura.com/articles/amazon-terra-preta-to-find-ancient-civilizations