August 3, 2020


Connecting People

Strange Glass Spheres Found in Ancient Florida Clams Point to Meteor Strike

This at first appeared in the July/August issue of Discover journal as “Information in a Clam.” Assistance our science journalism by getting a subscriber.

In abundant fossil deposits in southern Florida identified as the Pinecrest beds, ancient clams sit nestled in a mix of sand and clay, waiting to convey to their stories. In 2006, Michael Meyer joined his fellow undergraduates as they searched a quarry there for the fist-sized time capsules of ancient environments. The students were wanting inside of the clams for benthic foraminifera, solitary-celled organisms whose shells get on distinct shapes depending on their environments. Coiled or straight, spiraled still left or right, the foraminifera can expose what was taking place in their entire world three million a long time ago, when the beds were deposited. But Meyer, now an assistant professor of Earth methods science at Harrisburg University of Science and Technology in Pennsylvania, discovered a little something else in the clams, much too — while it took him about a 10 years to understand the significance of his discipline trip discover.

(Image: Michael B. Meyer)

In His Personal Text:

“We were opening these useless clams and all of a sudden took place upon all of these minimal spheres. I thought, “What the heck are these?” They were the very same sizing selection as benthic foraminifera, but no a single realized what they were.

I collected all eighty four of them and went back to lab to process them. I also sent out a great deal of e-mails, but persons explained they didn’t assume they were everything. Other individuals advised a few of costly analyses on unusual devices that an undergraduate cannot obtain. We were in a position to examination the spheres by X-ray spectroscopy all-around two weeks after original discovery, but that only advised us the spheres were “silica abundant,” and that was it.

I retained them on a slide in a box, and for the past 13 a long time, when I had some time, I would convey out the spheres. My colleagues who know me very well would say, “How are individuals minimal unusual spheres performing?” As I matured as a researcher, I would discuss my way onto lab devices when I could get some cost-free analyses performed. 


Michael Meyer pictured. (Credit: Michael Meyer)

Lastly, in 2018, a far more sensitive X-ray spectroscopic investigation exposed that the spheres are microtektites: tiny bits of glass that type when a meteorite slams into Earth and spews molten content in a fine mist.

But there are nonetheless a number of mysteries: These microtektites are significant in sodium, which is uncommon due to the fact microtektites are created of silica and don’t typically have sodium. We nonetheless cannot fully clarify that. We also don’t know when they were shaped.

The quarry where by we discovered the clams has because been loaded as aspect of a true estate growth, so there is no way to go back and dig for far more. We have been asking neighborhood fossil hunters to glimpse in other quarries and seize this specific variety of clam and sediment samples to see if we can pull out any far more microtektites that may clear up these mysteries.”

— As advised to Jeanne Erdmann