Cu boulder dating 24hr online sex chat

The radiocarbon dates on the samples indicated the carbonate layer underlying the petroglyphs dated to roughly 14,800 ago.

Those dates, as well as additional geochemical data on a sediment core from the adjacent Pyramid Lake subbasin, indicated the limestone boulders containing the petroglyphs were exposed to air between 14,800 and 13,200 years ago and again between about 11,300 and 10,500 years ago.

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.

cu boulder dating-69cu boulder dating-5

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." Benson obtained permission to non-invasively examine the petroglyphs from the Pyramid Lake Paiute Tribe, which owns the land.

A paper on the subject was published this month in the . Previous work by Benson showed the carbonate coating elsewhere in the basin at that elevation had a radiocarbon date of roughly 11,000 years ago.

Co-authors on the study included Eugene Hattori of the Nevada State Museum in Carson City, Nev., John Southon of the University of California, Irvine and Benjamin Aleck of the Pyramid Lake Paiute Tribe Museum and Visitor's Center in Nixon, Nev. Benson sampled the carbonate into which the petroglyphs were incised and the carbonate that coated the petroglyphs at the base of the limestone boulder.

The elevation was key to the study because it marked the maximum height the ancient lake system could have reached before it began spilling excess water over Emerson Pass to the north.

When the lake level was at this height, the petroglyph-peppered boulders were submerged and therefore not accessible for carving, said Benson, an adjunct curator of anthropology at the University of Colorado Museum of Natural History. According to Benson, a white layer of carbonate made of limestone precipitated from the ancient, overflowing Winnemucca Lake had coated some of the petroglyph carvings near the base of the boulders.

They found the infants had different mothers and were the northernmost known kin to two ...

Only the data you took should be the same among reports from the same lab group.

"Prior to our study, archaeologists had suggested these petroglyphs were extremely old," said Benson, also an emeritus USGS scientist.

Tags: , ,