Researchers Determine Winnemucca Lake Petroglyphs Are at Least 10,500 Years Old

Posted on August 14, 2013

Winnemucca Lake petroglyphs

Analysis led by a University of Colorado Boulder researcher has determined that the Winnemucca Lake petroglyphs are the oldest known petroglyphs in North America. The petroglyphs are cut into several bolders in western Nevada. The analysis found the ancient rock art is at least 10,500 years aold and could date as far back as 14,800 years ago.

The petroglyphs consist of large, deeply carved grooves and dots forming complex designs on several large limestone boulders. There are no people, animals or handprint symbols depicted in the rock art. The researchers say the petroglyph designs "include a series of vertical, chain-like symbols and a number of smaller pits deeply incised with a type of hard rock scraper." The rock art has been known about for decades.

CU-Boulder researcher and emeritus USGS scientist Larry Benson led the new dating effort. Benson and his colleagues used several methods to date the petroglyphs, including determining water levels of surrounding lakes and sampling the carbonate into which the petroglyphs were incised.

Benson said in a statement, "Prior to our study, archaeologists had suggested these petroglyphs were extremely old. 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."

Benson also says, "We have no idea what they mean. 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 size."

Photo courtesy University of Colorado

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