Deep in the flooded caves, researchers find evidence of America’s first miners.

Sam Meacham has spent years studying the miles of caves below the Mexican Yucatan region.

Although they are now flooded, most caves in the state of Quintana Roo were dry and accessible until about 8,000 years ago, when sea level rose at the end of the last Ice Age. The ancestors of modern Native Americans were known to venture into the dark caves, which stretch hundreds of miles below the limestone landscape. Human bones have been found deep in the caves, hundreds of meters from the entrances, and archaeologists have proposed that people go there in search of fresh water or to perform rituals.

Meacham and his CINDAQ diving team had seen “strange” things in other parts of the Sagittarius cave, such as signs of excavation and piles of rocks, which they could not explain. Then in 2017 Meachem was mapping a section of the cave known as La Mina, beyond a narrow part of its passage from the surface, when he found something that has changed the way archaeologists think of the earliest villages in the Americas.

“When we slipped down the narrow passageway to the other side … everything finally fell into place,” Meacham said.

Meacham found signs that people mined there more than 10,000 years ago to obtain a valuable pigment, red ocher, which is known to be used in rituals, according to research published Friday in the journal Science Advances.

Divers saw ample evidence of red ocher mining, including wells dug into the cave floor, vivid traces of ocher, stone tools, and charcoal to provide light.

The discovery makes ancient cave explorers the first miners in America.

A diver examines a navigation landmark in the now-flooded cave, left by former ocher miners more than 10,000 years ago.CINDAQ.ORG

Red ocher is a mineral rich in iron oxides used as a red pigment by many ancient cultures.

Its color has been symbolically compared to the color of blood, and it was used in rituals for hundreds of thousands of years, especially in burials and body paintings.

It may also have had medicinal uses, and could be used to tan skin or as a pest repellent.

“Red ocher played multiple roles within these communities,” said Brandi MacDonald, an archaeologist at the University of Missouri and lead author of the research. “It could have served symbolic and utilitarian functions, and its uses could have changed over time.”

The researchers can’t say exactly how the ocher from the Quintana Roo caves was used, but it may have been especially valuable because it’s exceptionally fine-grained (“ready paint,” MacDonald said) and has high traces of arsenic, which could have improved. its medicinal qualities.

The ancient ocher mine was discovered in 2017 in the Sagittarius cave, about 5 miles from the Caribbean coast.

Research shows that the mine dates to between 11,400 and 10,700 years ago, a few thousand years after humans arrived in America from Asia, and that at least two other nearby caves were also used to mine red ocher.

“It must have been very valuable in terms of the amount of effort to find it and [mine] “said geoarchaeologist Eduard Reinhardt of McMaster University, a lead author who dived into La Mina to sample the old mine.” It required a lot of social organization. “

A diver samples coal in the Sagittarius cave in Mexico’s Yucatan region, the site of the oldest ocher mine found in the Americas.CINDAQ.ORG

Teams of at least three people carried out the mining, removing rocks and stalagmites to dig wells in the cave floor where the ocher deposits were found, said archaeologist James Chatters of Applied Paleoscience, another of the lead authors.

Others likely transported firewood to keep the cave burning and took the mined ocher outside, he said.

Some of the bones in the caves of Quintana Roo appear to be from people who had lost their way.

“If you let your fire go out, 600 [yards] deep in the cave system, you’re in trouble, “Chatters said. “It is a maze.”

Archaeologist Loren Davis of Oregon State University, who was not involved in the research, explained that very little evidence of the earliest humans survives in Yucatan.

“It is a hot and humid jungle and things just don’t keep well there,” he said. “The researchers have basically found the ideal place where archaeological information will be preserved.”

Anthropologist Matthew Des Lauriers, from California State University, San Bernardino, said the study showed that the first peoples of the United States did their best to extract the ocher, an unequivocal sign that they shared the same interests as other peoples. ancient.

“The path our ancestors took is marked with ocher red,” he said. “Finding these unique human expressions, and in this great antiquity, in the Americas is really special.”

Denise Chow contributed