Mexico Caves Reveal Ancient Ochre Mining

60-Second Science


Sometimes, discoveries seem so simple. You know basically we've found a bunch of holes in the ground that's Edward Reinhard he's an archaeologist and geologist at McMaster University in Ontario Canada, but you know ultimately very important holes in the ground reinhard on colleagues believe they've found some of the first clear evidence of mining activity in a system of caves in Kintana ru on the peninsula the fine dates back to between ten and twelve thousand years ago. These are some very early people that have come and migrated to the Americas via the during straight. But getting to what remains of these miners and the tools they laugh is a challenge like cave divers you got to be so careful you don't get lost. These caves systems in Mexico, which were once dry are now completely filled with water. Thanks to a warming climate and sea levels that rose over time winding passageways are narrow and dark, and the walls are made of unforgiving limestone porous and with sharp edges. Reinhard says the water that filled the caves has preserved everything. It's basically almost like you know somebody working at a factory, they turn the lights off and they went away and nobody ever came back when divers started telling reinhard about what they were seeing inside the cave. He decided to go for a dive himself. He found concentrations of charcoal meaning that the people who walked here thousands of years ago probably used fire to light their way and there are stone. Cairns which Reinhardt believes the people built as navigation markers. Also says lots of tools remain and they were made from the stalagmites that hung from the cave ceiling breaking off and then using use hammer. So you can see the percussion marks where they were banging up the you know breaking up the stone on the bottom. The discovery is in the journal Science advances. So what were these ancient people mining and prospecting for there is a little bit of sediment still on the wall of. The pit. So I grabbed a vial and my sampled island, grab some of the sediment and underwater the red light gets attenuated. So Look Kinda Brown I was thinking well, maybe it's ochre you know is thinking about that but it's like well, looks Kinda creepy of that's what it is but then I got got out of the cave into the sunlight and it was just like this spectacular bright bright red. So then I knew. What they were after ochre it's among the earliest known pigments employed by humans and it's got many uses for sunscreen to preserve animal skins and burials and ceremonies, and people still use it even today in artwork. It was you know it's a prominent in used Gio material if you will through time for your end and dates data usage for thousands of years prior to around the world.

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