Archaeologists Find 16,000-Year-Old Stone Flake Tool in Oregon
A group of archaeologists from the University of Oregon and
the Bureau of Land Management has found an at least 15,800-year-old
orange agate tool at a rockshelter site near Riley, Oregon – a tool that
points to one of the earliest human occupations in the western United
States.
The team has been excavating at the site – the Rimrock Draw Rockshelter – since 2011.
Their discoveries have included a number of stone projectile points and tooth enamel fragments likely belonging to a prehistoric camel (Camelops sp.) that became extinct approximately 13,000 years ago.
But what has archaeologists most excited is a small orange agate tool found below a layer of volcanic ash.
Near the bottom of a 12-foot (3.7 m) deposit, the scientists discovered a layer of ash that was identified as volcanic ash from a Mt. St. Helens eruption about 15,800 years ago.
Beneath the layer of volcanic ash, archaeologists discovered a small flake tool believed to have been used for scraping animal hides, butchering, and possibly carving wood.
“It’s a very even layer of volcanic ash. Based on its position within the site’s overall stratigraphy, it’s unlikely that there has been any significant upward or downward movement over these many thousands of years,” said Dr Patrick O’Grady from the University of Oregon’s Museum of Natural and Cultural History, director of the Rimrock Draw excavations.
“The discovery of this tool below a layer of undisturbed ash that dates to 15,800 years ago means that this tool is likely more than 15,800 years old, which would suggest the oldest human occupation west of the Rockies,” said Dr Scott Thomas, BLM Burns District archaeologist.
According to the archaeologists, the flake tool was likely used for butchering and scraping animal hides.
The blood residue analysis of the tool revealed animal proteins consistent with bison, the most likely species being Bison antiquus, an extinct ancestor of the modern buffalo.
“When we had the volcanic ash identified, we were stunned because that would make this stone tool one of the oldest artifacts in North America. Given those circumstances and the laws of stratigraphy, this object should be older than the ash,” Dr O’Grady said.
“While we need more evidence before we can make an irrefutable claim, we plan to expand our excavation this summer and hopefully provide further evidence of artifacts found consistently underneath that layer of volcanic ash. That’s the next step.”
“For years, many in the archaeological field assumed that the first humans in the western hemisphere were the Clovis people – dating to around 13,000 years ago,” said Dr Stan McDonald, BLM Oregon/Washington lead archaeologist.
“While a handful of archaeological sites older than Clovis cultures have been discovered in the past few decades, there is still considerable scrutiny of any finding that appears older.”
“With the recent findings at Rimrock Draw Shelter, we want to assemble indisputable evidence because these claims will be scrutinized by researchers. That said, the early discoveries are tantalizing.”
Agate
stone flake tool found beneath the volcanic ash at the Rimrock Draw
Rockshelter, Riley, Oregon. Image credit: University of Oregon.
Their discoveries have included a number of stone projectile points and tooth enamel fragments likely belonging to a prehistoric camel (Camelops sp.) that became extinct approximately 13,000 years ago.
But what has archaeologists most excited is a small orange agate tool found below a layer of volcanic ash.
Near the bottom of a 12-foot (3.7 m) deposit, the scientists discovered a layer of ash that was identified as volcanic ash from a Mt. St. Helens eruption about 15,800 years ago.
Beneath the layer of volcanic ash, archaeologists discovered a small flake tool believed to have been used for scraping animal hides, butchering, and possibly carving wood.
“It’s a very even layer of volcanic ash. Based on its position within the site’s overall stratigraphy, it’s unlikely that there has been any significant upward or downward movement over these many thousands of years,” said Dr Patrick O’Grady from the University of Oregon’s Museum of Natural and Cultural History, director of the Rimrock Draw excavations.
“The discovery of this tool below a layer of undisturbed ash that dates to 15,800 years ago means that this tool is likely more than 15,800 years old, which would suggest the oldest human occupation west of the Rockies,” said Dr Scott Thomas, BLM Burns District archaeologist.
According to the archaeologists, the flake tool was likely used for butchering and scraping animal hides.
The blood residue analysis of the tool revealed animal proteins consistent with bison, the most likely species being Bison antiquus, an extinct ancestor of the modern buffalo.
“When we had the volcanic ash identified, we were stunned because that would make this stone tool one of the oldest artifacts in North America. Given those circumstances and the laws of stratigraphy, this object should be older than the ash,” Dr O’Grady said.
“While we need more evidence before we can make an irrefutable claim, we plan to expand our excavation this summer and hopefully provide further evidence of artifacts found consistently underneath that layer of volcanic ash. That’s the next step.”
“For years, many in the archaeological field assumed that the first humans in the western hemisphere were the Clovis people – dating to around 13,000 years ago,” said Dr Stan McDonald, BLM Oregon/Washington lead archaeologist.
“While a handful of archaeological sites older than Clovis cultures have been discovered in the past few decades, there is still considerable scrutiny of any finding that appears older.”
“With the recent findings at Rimrock Draw Shelter, we want to assemble indisputable evidence because these claims will be scrutinized by researchers. That said, the early discoveries are tantalizing.”
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