July 15, 2012
Oregon Artifacts Stir Up Debate On Earliest Americans
Brett Smith for redOrbit.com - Your Universe Online
Artifacts found in Oregon have once again stirred up the debate surrounding the earliest Americans and how they came to live in the Western Hemisphere.
A team of mostly American researchers led by Dennis L. Jenkins, a University of Oregon archeologist, recently described the finding of several small spearheads and hunting tools along with human feces in the Paisley Cave complex that dated back to around 13,000 years ago. Their report was published recently in the journal Science.
Carbon dating of the preserved feces found at the same archeological level as the tools implies that the hunting implements are at least as old as the famous Clovis tools from New Mexico, which some say belonged to North America´s earliest inhabitants. Western Stemmed and Clovis artifacts come from two different cultures – meaning that these two groups of people most likely did not share a common heritage.
"The big 'aha!' here, or the primary significance of this is that ... we have demonstrated that these western stemmed tradition points are the same age as Clovis," Jenkins said in a conference call with reporters (MP3). "There is no evidence of Clovis or any precursor to Clovis in the caves currently, and so that suggests that you've got here, at the exact same time, at least two technologies."
Western Stemmed projectile points, which differ from Clovis points at their base, have been found at archeological sites in the western US and evidence has suggested that they are more recent than their Clovis counterparts.
However, Jenkins-led research group demonstrated through radiocarbon dating techniques that the Paisley artifacts were being used around the same time and quite possibly before the Clovis tools. The researchers also tested to see if the samples had been contaminated by the cave´s later inhabitants.
“In the dating process, we would take the sample and put it in distilled water first and then take the solutes or the removable portion of carbon that had attached itself to the coprolite and would remove that, freeze-dry it and then run the radiocarbon date on the solubles as well on the macrofossils or the plant materials inside the coprolite,” Jenkins said in an online video.
“This allowed us to test to see if DNA was moving through the soil due to water or urine–taking DNA that was younger and intruding it into an older coprolite.”
Multiple tests placed the feces samples, which the scientists called coprolites, at 13,200 years before the present day, making them as old as Clovis technology found in other parts of North America.
The scientists did date some Paisley feces samples as far back as 14,500 years ago, but no stone tools were found alongside those specimens.
"We've got people in the cave at [14,500 years ago]; we have them showing up again right down through 13,000 years [ago], and there's no evidence of Clovis or precursor to Clovis. Therefore, the most likely answer is that it's Western Stemmed - but we have not proven that," Jenkins told the BBC.
Archeologists are not sure if Western Stemmed weaponry represented a completely separate immigrant population to those using Clovis technology. Scientists do say that the traditions of the two groups are different and this latest study suggests Clovis is not a likely precursor to Western Stemmed.
Image 2 (below): Dennis Jenkins with a human coprolite (dried feces) found in Oregon's Paisley Caves. Credit: Jim Barlow