Mystery Disk
© Scott ShirarUA Museum of the North fine arts collection manager Mareca Guthrie makes a tracing of the petroglyph-adorned boulder that marks one of the prehistoric house pit at Feniak Lake.

Mysterious disks found at an archeological dig in Northwest Alaska have experts puzzled.

The four small pieces, formed from clay, are round and adorned with markings. Two have neatly centered holes. They may be 1,000 years old and, at the moment, what they were used for is anyone's guess.

The existence of similarly-decorated boulders at old village sites in Noatak National Preserve was first recorded by archeologists in the 1960s. But the sites remained unstudied until last summer when Scott Shirar, a research archeologist at the University of Alaska Museum of the North, took an expedition for a closer look at two locations.

Making small-scale excavations, they came upon the disks.

"The first one looks like a little stone that had some scratch marks on it," said Shirar. "We got really excited when we found the second one with the drilled hole and the more complicated etchings on it. That's when we realized we had something unique.

"We only opened up a really small amount of ground at the site, so the fact that we found four of these artifacts indicates there are probably more and that something really significant (was) happening."

The artifacts were unusual in several respects. They were made of clay, not carved from stone or bone. In the course of the excavations, the team encountered a fine gray clay that could have been worked to make the objects which were, Shirar said, "definitely hand made."

Then there are the markings. Petroglyphs -- the catch-all term for any human-made marks on natural stone -- are found around the world and are common in southeast Alaska and the Kodiak region.

"But there are only a handful of examples in northern and interior Alaska," Shirar said. "They're very rare."

The meaning behind the petroglyphs is a source of conjecture for archeologists, he said. "It's almost limitless the ideas you can come up with."

Those ideas range from maps or storytelling to mystical symbols or simple artistic decoration.

"It's the first time we've found anything like that," Shirar said. "We've combed through the collections here at the museum and found a similar, though not identical, ivory disk from St. Lawrence Island."

The Alutiiq Museum and Archeological Repository in Kodiak also has items somewhat like the ones from the Noatak region that may have been lids.

Other theories include speculation that they were gaming pieces -- think of prehistoric arctic dreidels -- or used for ornamentation, like beads or amulets. They're quite light, Shirar said, fragile and small. One only measured two centimeters across.

The presence of the hole in the middle of the disk shape calls to mind a spindle whorl, Shirar said. That would raise the possibility that people were spinning something, rope or lines if not plant fabric or wool yarn.

Each of the documented sites in the preserve have numerous habitation and storage pit features, Shirar said. And each at one time had a large communal dwelling built on boulders weighing several hundred pounds and measuring four to five feet across. Some of the petroglyphs on the boulders appear to mimic the etchings found on the clay disks.

Over the winter the museum team will perform more extensive research on the disks and try to get a better fix on their age. Based on what he observed, Shirar said the sites "likely date within the last thousand years sometime but we won't know for sure until we get the radiocarbon dates back."

The National Park Service funding that paid for the UA museum team's visit to two sites in the Preserve this summer also covers a trip to a third site next year.

That grant only covered two summers, Shirar said. "But now that we've made these fairly significant finds, we'll probably try to get some additional funds."