A team of divers exploring an underwater cave in the Yucatan Peninsula discovered evidence of mining activity from thousands of years ago, when the caves were dry.
Divers found tools, mining pits, the charred remains of campfires, stone markers, and other artifacts left behind by the Indigenous peoples who mined the caves for red ochre - a valuable mineral used for both mundane and ritualistic purposes.
The cave is a “time capsule underwater,” says lead study author Brandi MacDonald. “It’s a really rare opportunity to get to see something with such amazing preservation.”
Evidence of mining was first discovered in 2017, when divers found a way to swim into the Sagitario cave system. What they found explained some of the oddities divers discovered in nearby caves.
“Over the years, we have seen these anomalous weird things within caves that we couldn’t quite explain - rocks out of place, rocks stacked on top of each other, things that just didn’t seem natural.”
The Sagitario system and other caves in the Yucatan Peninsula were dry until the end of the last ice age, when glaciers melted and sea levels rose. This occurred between 13,000 and 8,000 years ago.
Based on carbon dating, Indigenous people mined the caves of the Yucatan Peninsula for ochre between 11,400 and 10,700 years ago.
The unexpected discovery proves that “early human groups in the Americas were already engaged in complex activities that went much beyond their own survival,” explains Mark Hubbe, a professor of anthropology at Ohio State University.
“The mining of ochre from the caves suggests that there was an important social meaning to this mineral and, even though we cannot really say what they were using this material for at this point, it does show it was immensely valuable and important to them.”
Based on the ochre’s high arsenic content, some researchers think it was used as bug repellant.
By Alice Greene