[freebeard]

You surprise me, being from Brazil and all.

terra preta do índio

You do realize the Amazon Basin was once a vast orchard?

Searching for the Amazon's Hidden Civilizations | Science | AAAS

Terra preta—literally “black earth”—is soil that humans have enriched to have two to three times the nutrient content of the surrounding, poor-quality soil, explains Crystal McMichael, a paleoecologist at the Florida Institute of Technology in Melbourne. Although there is no standard definition for terra preta, it tends to be darker than other Amazonian soils and to have charcoal and pre-Columbian pottery shards mixed in. Most of it was created 2500 to 500 years ago. Like the earthworks, terra preta is considered a sign that a particular area was occupied by humans in the pre-Columbian past.

Archaeologists Will Use Drones to Search the Amazon - Archaeology Magazine

Dark earth, cultivated by humans to create raised agricultural fields, and geoglyphs made up of large ditches, can be spotted from the air by drones carrying Lidar technology, which uses lasers to map the topography of the ground.