Alaska News

Carbon dating woolly mammoth remains from Kenai's Pleistocene history

Eleven-year-old Grace Mills recently thought she'd found an interesting rock. When she took it back to the family fish camp on the beach between Ninilchik and Clam Gulch, her grandfather, Brent Johnson, identified her find as something other than a rock. It was a woolly mammoth tooth.

"Luckily I had attended Janet Klein and Dick Reger's presentations and I knew right away what it was," said Johnson who had heard talks describing woolly mammoth remains found on the Kenai Peninsula given by Klein, a Homer author who has written several books on local history and anthropology, and Reger, a Soldotna geologist.

After being notified by Johnson of his granddaughter's find, Klein and Reger visited the beach site and were given permission to remove a piece of the tooth for radiocarbon dating. Now the wait begins to see where it fits in the area's historical timeline.

Judging by the size of Mills' find — the molar is more than 6 inches long — the mammoth it came from may have been a young one.

"I am so pleased that we have a young person finding a molar from a younger mammoth, even though it meant that the mammoth died before it had reached its potential life span of about 60 years of age," said Klein.

More than 48,500 years old

In March 2011, Klein and Reger announced that radiocarbon dating by the University of California Irvine of two remains indicated evidence that woolly mammoths lived on the Kenai Peninsula between 60,000-25,000 years ago. A tusk fragment found on the beach between Homer and Anchor Point by Mike Lettis was placed at about 27,040 years ago, and an anklebone found near Bishop's Beach by Klein exceeded the limits of radiocarbon dating, or older than 48,500 years ago.

That news led to attention to a woolly mammoth tooth on display at Alaska Wild Berry Products in Homer that was found on the beach near Homer by Jack Klingbeil in the late 1950s. Since then, more pieces — some founds years ago and others found recently — have been reported to Klein and Reger.

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Last week, Klein announced "a most unusual batch of dates" indicated by radiocarbon dating of three recent samples, that add to what is known of the peninsula's Pleistocene history.

"One was the molar from Alaska Wild Berry Products and the date on that was greater than 46,100 years," said Klein.

A small tusk fragment found by Klein was dated at 28,200. A rib found by Joyce Robinette tested at older than 46,100 years, but isotope values indicate it is from a carnivore, "possibly a marine mammal or a salmon-eating bear," said Klein.

A fourth specimen, found by Lettis' wife, Sandy, a few miles south of the mouth of Anchor River earlier this year also proved unusual. "It was initially identified as moose or elk, and we felt it was important to submit for radiocarbon dating," said Klein.

Random beach find

The results: a date of 1965, and the presence of bomb carbon. Bomb carbon refers to the addition of "artificial" radiocarbon to the atmosphere as a result of nuclear weapons testing, according to information provided online by Beta Analytic Radiocarbon Dating.

"My understanding is that in the late 1950s a lot of nuclear testing was going on in China and the U.S. and different countries and this bomb carbon would show up in a lot of animals," said Sandy Lettis. "They could see it in domestic animals, but I'm not sure they tested a lot of wild animals."

The finding is significant enough that the lab has asked Lettis if she will let the lab keep it. "I wanted to have it back because my mom and friends hadn't seen it, but I'll definitely send it back to them," she said. Klein said the lab's interest in the bone has raised more questions.

"Why is it important? Because it was found in Alaska? Because of its age? Because of its species? As of yet, we don't have answers to our many, many questions," said Klein. "That's the conundrum we're dealing with."

As with the tooth recently found by Mills, Lettis found the femur while walking on the beach. "There was just a little bit showing. I walked by it and thought, 'man, that could be a bone,'" said Lettis, who, with her husband's help, retrieved it from the rocks and mud.

Radiocarbon testing has been paid by donations to Klein and Reger by individuals interested in piecing together the peninsula's history.

"The folks on the peninsula are to be thanked and commended for opening their wallets," said Klein. "Since we're not a nonprofit, there's no tax write-off; it's just knowledge, pure knowledge, knowing what was here and when it was here."

For more about radiocarbon dating and carbon bombs, check this.

McKibben Jackinsky is a reporter for the Homer News who can be reached at mckibben.jackinsky@homernews.com. Used with permission.

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