Researchers analyzing fossilized clams unearthed from a quarry in Sarasota County in Florida made an unusual discovery: dozens of tiny, silica-based glass beads.
These glass beads are forged under extreme heat, typically through volcanic or industrial activity. However, the researchers suggested that these ancient spheres were produced by a powerful meteorite impact.
They are called microtektites: particles that form when an object from space slams into the Earth, sending molten debris into the atmosphere where it cools and recrystallizes before falling into the ground. The researchers said that these are the first documented microtektites in Florida and possibly the first to be found inside a fossilized clam.
Unusual Glass Beads Trapped In Fossilized Clams
The microtektites were discovered by Mike Meyers from the University of South Florida in 2006. He and other students were sent to collect fossils from the quarry. He pried open fossil clams, washed the sediment trapped inside, and found the glass balls.
"They really stood out," he said in a press release. "Sand grains are kind of lumpy, potato-shaped things. But I kept finding these tiny, perfect spheres."
Meyer found a total of 83 glass balls, all of which are smaller than a grain of salt. He kept the objects inside a box for more than a decade, but his curiosity persisted. A couple of years ago, he began investigating what these glass balls actually were and where they came from.
He analyzed the elemental makeup and the physical features of the glass balls. He compared them to other microtektites, volcanic rock, coal ash byproducts of industrial processes. Meyer concluded that the glass balls had extraterrestrial origins.
Ancient Cosmic Pearls
Further analysis revealed that the glass balls have traces of "exotic metals" further supporting the claim that the objects were forged from a meteorite impact.
Roger Portell, who was also involved in the project, explained how the microtektites likely ended up inside the fossilized clams. He said that as clams die, fine sediment and particles settle inside. As time passes by and more sediments settle on top of the clam, they close, trapping the objects inside it to be preserved.
Inside the fossilized clams, the researchers also found crabs and fish skeletons.
The researchers plan to date the microtektites. Portell estimated that the glass balls are around 2 to 3 million years old.
Details of the discovery were published in the Meteoritics and Planetary Science.
