Sure, archaeologists in Northwest Alaska’s Noatak National Preserve expected to find plenty of rocks, everything from mundane pebbles to petroglyph-adorned boulders. But now researchers from University of Alaska Museum of the North aren’t sure what they really have after unearthing four decorated clay disks.
Searching three prehistoric lakefront dwellings, archaeologist Scott Shirar says the first disk didn’t look like much more than a stone with scratches. It was the second one “with the drilled hole and the more complicated etchings” that got his research team enthralled. And as archaeological digs go, the electrifying atmosphere only picked up at Feniak Lake with the discovering of disks three and four.
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Having found four similar disks in a relatively small area, Shirar thinks the team has stumbled into the early stages of new discoveries at the site. But what are they really discovering? Researchers don’t know, but say that given the house features and other information already found, they think whatever they have—and continue looking for more of—comes from the late prehistoric era or the past thousand years.
“These objects and places clearly had special significance to their makers,” Shirar says. “These finds offer an especially tangible reminder of the rich spiritual and intellectual lives they led.”
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Tim Newcomb is a contributor for TIME. Find him on Twitter at @tdnewcomb. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.