ICE PATCHES REVEAL ANCIENT ARTIFACTS

Craig Lee, a research associate with University of Colorado-Boulder's Institute of Arctic and Alpine Research has found an atlatl dart, a spear-like hunting weapon, melting out of an ice patch high in the Rocky Mountains close to Yellowstone National Park (USA). Lee, a specialist in the emerging field of ice patch archaeology, said the dart had been frozen in the ice patch for 10 millennia and that climate change has increased global temperatures and accelerated melting of permanent ice fields exposing organic materials that have long been entombed in the ice.

"We didn't realize until the early 2000s that there was a potential to find archaeological materials in association with melting permanent snow and ice in many areas of the globe," Lee said. "We're not talking about massive glaciers, we're talking about the smaller, more kinetically stable snowbanks that you might see if you go to Rocky Mountain National Park." As glaciers and ice fields continue to melt at an unprecedented rate, increasingly older and significant artifacts - as well as plant material, animal carcasses and ancient feces - are being released from the ice that has gripped them for thousands of years, he said.

Over the past decade, Lee has worked with other researchers to develop a geographic information system, or GIS, model to identify glaciers and ice fields in Alaska and elsewhere that are likely to hold artifacts. They pulled together biological and physical data to find ice fields that may have been used by prehistoric hunters to kill animals seeking refuge from heat and insect swarms in the summer months.

The dart Lee found was from a birch sapling and still has personal markings on it from the ancient hunter, according to Lee. When it was shot, the 3-foot-long dart had a projectile point on one end, and a cup or dimple on the other end that would have attached to a hook on the atlatl. The hunter used the atlatl, a throwing tool about two feet long, for leverage to achieve greater velocity.

Later this summer Lee and CU-Boulder student researchers will travel to Glacier National Park to work with the Salish, Kootenai and Blackfeet tribes and researchers from the University of Wyoming to recover and protect artifacts that may have recently melted out of similar locations. Quick retrieval of any organic artifacts like clothing, wooden tools or weapons is necessary to save them, because once thawed and exposed to the elements they decompose quickly, he said.

Sources: University of Colorado, EurekAlert! (29 June 2010), ScienceDaily (30 June 2010)
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