Winnemucca Lake petroglyphs. Credit: Benson, Larry V. and Hattori, E.M. and Southon, J. and Aleck, B., University of Colorado Boulder.
Sci-news.com echoed the following publication:
- L. V. Benson, E. M. Hattori, J. Southon, and B. Aleck, “Dating North America’s oldest petroglyphs, Winnemucca Lake subbasin, Nevada,” Journal of Archaeological Science, vol. 40, iss. 12, pp. 4466-4476, 2013.
[Bibtex]@Article{BensonHattoriSouthonEtAl2013, author = {Benson, Larry V. and Hattori, E.M. and Southon, J. and Aleck, B.}, title = {Dating North America's oldest petroglyphs, Winnemucca Lake subbasin, Nevada}, journal = {Journal of Archaeological Science}, year = {2013}, volume = {40}, number = {12}, pages = {4466-4476}, month = dec, abstract = {On the west side of the Winnemucca Lake subbasin, Nevada, distinctive deeply carved meter-scale petroglyphs are closely spaced, forming panels on boulder-sized surfaces of a partially collapsed tufa mound. The large, complex motifs at this side are formed by deeply carved lines and cupules. A carbonate crust deposited between 10 200 and 9800 calibrated years B.P. (ka) coats petroglyphs at the base of the mound between elevations of 1202 and 1206 m. Petroglyphs above the carbonate crust are carved into a branching form of carbonate that dates to 14.8 ka. Radiocarbon dates on a multiple-layered algal tufa on the east side of the basin, which formed at an elevation of 1205 m, as well as a sediment-core-based total inorganic carbon record for the period 17.0–9.5 ka indicate that water level in the Winnemucca Lake subbasin was constrained by spill over the Emerson Pass Sill (1207 m) for most of the time between 12.9 ± 0.3 and ≥9.2 ka. These and other data indicate that the lake in the Winnemucca Lake subbasin fell beneath its spill point between 14.8 and 13.2 ka and also between 11.3 and 10.5 ka (or between 11.5 and 11.1 ka), exposing the base of the collapsed tufa mound to petroglyph carving. The tufa-based 14C record supports decreased lake levels between 14.8–13.2 ka and 11.3–10.5 ka. Native American artifacts found in the Lahontan Basin date to the latter time interval. This does not rule out the possibility that petroglyph carving occurred between 14.8 and 13.2 ka when Pyramid Lake was relatively shallow and Winnemucca Lake had desiccated.}, date = {2013}, doi = {10.1016/j.jas.2013.06.022}, journaltitle = {Journal of Archaeological Science}, keywords = {Petroglyphs; Rock art; Great Basin; Winnemucca Lake; Pyramid Lake}, owner = {trismegisto}, timestamp = {2016-05-16}, url = {http://pubs.er.usgs.gov/publication/70118061}, urldate = {2016-05-16} }
I’ll quote some of the article here:
A new study reported in the Journal of Archaeological Science shows Winnemucca petroglyphs, the oldest known petroglyphs in North America, date to at least 10,500 years ago and perhaps even as far back as 14,800 years ago.
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Study lead author Dr Larry Benson of the University of Colorado Boulder explained: “the petroglyphs located at the Winnemucca Lake petroglyph site 35 miles northeast of Reno consist of large, deeply carved grooves and dots forming complex designs on several large limestone boulders that have been known about for decades.”
Although there are no people, animals or handprint symbols depicted, 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.
Dr Benson with colleagues used several methods to date the petroglyphs, including determining when the water level the Winnemucca Lake subbasin – which back then was a single body of water connecting the now-dry Winnemucca Lake and the existing Pyramid Lake – reached the specific elevation of 3,960 feet.