It builds up in layers, and Putnam thinks he can analyze them, like tree rings, to get an approximate date for when the images were actually made — not just when people could have first come.
Kortum is not certain it will succeed, but he has said it would be “a revolutionary result” — a climatological revelation accidentally inscribed in the art of Mongolia’s earliest peoples.
(Photo: Kevin Stark)The geologist crouches before the surface of a boulder, his finger hovering over an image of two ibex butting heads.
“Where the horns converge, there is a beautiful symmetry to them,” he says.
In the light of a Mongolian summer, the images seem to be suspended in air.
The glacial geologist, Aaron Putnam of the University of Maine, runs his hands along the greywacke sandstone, a common bedrock in this part of the Altai Mountains, on the shared border of Russia and China.
Despite the fact that I am now on the beach in Vietnam, have traversed several countries by train in the last few weeks, and am geographically veryveryvery far away from the windswept, bone-chilling sandstorms of the Mongolian spring, I am still writing about this country.
😉 Before I get started, I wanted to explicitely state my intentions in writing this article: to point to the dangers, from a feminist woman’s perspective, of feeding the fires of extreme nationalism and/or ethnic blood superiority rhetoric.
And down the line a few meters from me was a man speaking English and not Chinese like the rest. Guess it wasn’t everyday that a white woman walked up to him and spoke Mongolian.There are also petroglyphs of bulls and yaks, but these have clean edges and are more anatomically correct.Kortum says they are likely from the Neolithic period.They took up sharp stones and pecked the smooth rind of glacially polished rocks — not knowing that, eventually, every detail would be scrutinized.When it rains, a black mineral accumulates on the rocks — manganese oxide, sometimes called desert varnish.From this information, Putnam can derive a date for the end of the Ice Age, which is his primary interest: A clear chronology of glacial recession can help us improve scientific models that predict how anthropogenic climate change will affect future societies.The dates also approximate when the first people could have lived here, but Putnam thinks there’s another technique to determine when the rock art was actually made.He indicates the half-circle curl of the horns; the wild goats’ legs are straight thin lines.Petroglyphs like this one have been here for many thousands of years, since Stone Age people first began gouging the rock.Analyzing the petroglyphs is important for understanding the culture and movement of ancient people, but, when joined with a geologic examination, it can tell us a lot about the history of climate.Images of horses and camels, for example, indicate the domestication of animals and suggest an abundance of grassland in the area — which scientists can confirm by analyzing pollen that’s enclosed in sediment.