Oldest Rock Art in North America Revealed
Credit: University of Colorado
On the west side of Nevada's dried-up Winnemucca Lake, there are several limestone boulders with deep, ancient carvings; some resemble trees and leaves, whereas others are more abstract s that look like ovals or diamonds in a chain. The true age of this rock art had not been known, but a new analysis suggests these petroglyphs are the oldest North America, dating back to between 10,500 and 14,800 years ago.
Though Winnemucca Lake is now barren, at other times in the past it was so full of water the lake would have submerged the rocks where the petroglyphs were found and spilled its excess contents over Emerson Pass to the north. [See Photos of Amazing Cave Art]
To determine the age of the rock art, researchers had to figure out when the boulders were above the water line.
The overflowing lake left telltale crusts of carbonate on these rocks, according to researcher Larry Benson of the University of Colorado Boulder. Radiocarbon tests revealed that the carbonate film underlying the petroglyphs dated back roughly 14,800 years ago, while a later layer of carbonate coating the rock art dated to about 11,000 years ago.
Those findings, along with an analysis of sediment core sampled nearby, suggest the petroglyph-decorated rocks were exposed first between 14,800 and 13,200 years ago and again between about 11,300 and 10,500 years ago.
"Prior to our study, archaeologists had suggested these petroglyphs were extremely old," Benson said in a statement. "Whether they turn out to be as old as 14,800 years ago or as recent as 10,500 years ago, they are still the oldest petroglyphs that have been dated in North America."
Researchers previously believed the oldest rock art in North America could be found at Long Lake, Ore., in carvings that were created at least 6,700 years ago, before being covered in ash from the Mount Mazama volcanic eruption. [Formation of Crater Lake, eruption ca 4700 BC]
The deeply carved lines and grooves in geometric motifs in the petroglyphs at Winnemucca Lake share similarities with their cousins in Oregon. As for what the petroglyphs represented to their Native American creators, researchers are still scratching their heads.
"We have no idea what they mean," Benson said. "But I think they are absolutely beautiful symbols. Some look like multiple connected sets of diamonds, and some look like trees, or veins in a leaf. There are few petroglyphs in the American Southwest that are as deeply carved as these, and few that have the same sense of ."
The findings will be detailed in the December 2013 issue of the Journal of Archaeological Science.
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[There are similar areas of Petroglyphs in Mexico, Central and Mountainous South America and some area already thought to be the same age, about 9000 to 12000 BC, and they probably correspond to Rock Art in Spain, Italy and in the Sahara probably at the same age. Some of the geometric signs continue to be produced by South American natives and have supernatural meanings attached, and some of them are thought to be associated with patterns of light seen in hallucinations after ingesting certain drugs. Similar geometric signs also continue on into the Megalithic cultures, and the geometric figures make a break with the more naturalistic and older animal art traditions of the Cro-Magnons. There is another peculiar feature is that these petroglyphs are often associated with certain naturally shaped "Statues", being some formations of rock thought to bear a resemblance to animals or humans: doubtless these are also seen as being magical. These have been especially noticed in Peru but could be found throughout the Megalithic area as well, being large stones naturally venerated by the culture whose career was in moving large stones around and placing them precisely. All of these things presumably came from an older cultural package which believed in such things, made the petroglyphs, and likely also used drugs to promote visions.-DD]