Manaus, Brazil Reuters  — 

Human faces sculpted into stone up to 2,000 years ago have appeared on a rocky outcropping along the Amazon River since water levels dropped to record lows in the region’s worst drought in more than a century.

Some rock carvings had been sighted before but now there is a greater variety that will help researchers establish their origins, archaeologist Jaime de Santana Oliveira said on Monday.

Suamy Beydoun/Reuters
The ancient stone carvings were exposed when the Amazon's water level dropped during a drought in Manaus, Amazonas state.

One area shows smooth grooves in the rock thought to be where Indigenous inhabitants once sharpened their arrows and spears long before Europeans arrived.

“The engravings are prehistoric, or precolonial. We cannot date them exactly, but based on evidence of human occupation of the area, we believe they are about 1,000 to 2,000 years old,” Oliveira said in an interview.

Suamy Beydoun/Reuters
Institute for Public Health and Medicine (IPHAM) archaeologist Jaime de Santana Oliveira points to one ancient stone carving.

The rocky point is called Ponto das Lajes on the north shore of the Amazon near where the Rio Negro and Solimões rivers join.

Oliveira said the carvings were first seen there in 2010, but this year’s drought has been more severe, with the Rio Negro dropping 15 meters (49.2 feet) since July, exposing vast expanses of rocks and sand where there had been no beaches.

Suamy Beydoun/Reuters
The rocky point is where two rivers - the Rio Negro and Solimões - meet.

“This time we found not just more carvings but the sculpture of a human face cut into the rock,” said Oliveira, who works for the National Historic and Artistic Heritage Institute (IPHAN) that oversees the preservation of historic sites.