Swiss researchers have discovered nearly 10,000-year-old remnants of human settlements in Bolivia. The research is published August 28 in the open access journal PLOS ONE.
Prior to this research, experts believed the site to be uninhabited due to adverse environmental effects.
The archaeologists unearthed the site after analyzing forest islands. These islands are tiny forested mounds of earth that are spread across Amazonia. With the help of these mounds, scientists can reveal the history and human activity in an area.
In this project, University of Bern researchers found three shell middens or mounds of seashells that were left by settlers in the early Holocene period, around 10,400 years ago.
A dense accumulation of freshwater snail shells, animal bones and charcoal were found in the samples of soil, forming the mounds. The older layer of the soil consisted of snail shells, while the outer layer included pottery, bone tools and human bones.
These two layers are separated by a thin layer rich in pieces of burnt clay and earth and the topmost layer of this thin layer also revealed remains of earthenware pottery.
When the researchers conducted Radiocarbon analysis of two middens, they found that humans settled in the Bolivia Amazon region during the early Holocene and shells and other relics formed mounds over a 6,000 year period.
They also claimed that the settlers may have dumped the area due to wetter conditions.
'We have discovered the oldest archaeological sites in western and southern Amazonia. These sites allow us to reconstruct 10,000 years of human-environment interactions in the Bolivian Amazon,' said Study author Doctor Umberto Lombardo, from the University of Bern.
