In recent years, however, well documented earlier sites like Chile’s Monte Verde have convinced most archaeologists that humans made it deep into the Americas by 14,500 years ago, meaning that they would have had to cross Canada long before an ice-free corridor existed.
That makes Huaca Prieta one of the oldest archaeological sites in the Americas and suggests that the region’s first migrants may have moved surprisingly slowly down the coast.
But geologists on his team wanted to study the landform under the mound, so “we just kept going down,” he says.
The deepest pit, which took 5 years to excavate, reached down 31 meters.
Sources of copper ore have been found within 44 miles (70 kilometers) of the location where the mask was uncovered, suggesting that it was produced locally.
It is therefore highly probably that metalworking emerged in Argentina at the same time that it was developing in Peru, the researchers wrote in the study. 1000 were previously found in the Peruvian Andes, though it is difficult for experts to say for sure if the objects originated where they were found, or if trade brought them there, Live Science reported in 2007.