Southwest Amazonia

LiDAR Survey Reveals More Than 20,000 Amazonian Earthworks

A study using canopy-penetrating LiDAR has expanded the known distribution of precolonial earthworks in southwestern Amazonia. The researchers tentatively estimate that the region’s population reached between 1.25 million and 3 million people around AD 100–300, although the estimate depends on evidence from a limited survey area.