||Archaeologists used X-ray fluorescence to analyze a woman's portrait in an early twentieth-century sheepherder's barn in central Wyoming. The pigment used in the barn turned out to be identical to that found on abstract "rock art" panels at a nearby site, suggesting the works were actually paint smears left by sheep marked for breeding purposes. (Courtesy Bonita A. Newman)
Ewes with painted rumps are responsible for creating some "rock art" panels in central Wyoming. That's what researcher Bonnie Newman, of the Museum of New Mexico's Office of Archaeological Services, and New Mexico State University archaeologist Larry Loendorf discovered when they compared suspiciously abstract paint smears at the Notches Dome site with paint found at a nearby historic shepherds' camp. X-ray fluorescence spectrometer analysis revealed that the blue, green, and red paint smeared onto Notches Dome rock projections was chemically very similar to the paint used in a woman's portrait on a barn wall at the sheep camp. Ewes marked with paint for breeding and branding purposes had probably taken shelter beneath the rock ledges, where they left paint smears later mistaken for rock art.
|Click thumbnails for larger versions. (Courtesy Bonita A. Newman)
Notches Dam archaeologists John and Mavis Greer, who called Newman and Loendorf in, weren't surprised by the results. Probably dating to the seventeenth century, the genuine rock art there generally depicts figures on horseback and other representational forms. And while the style is known as the Foothills Abstract Tradition, the sheep paintings were a little too abstract.
Because of their rarity in rock art, the presence of prehistoric green or blue paint at Notches Dam would have had interesting implications about contact with cultures from the southwest or the north, where those colors are sometimes found. But the Greers aren't disappointed. They are using the sheep art markers to reevaluate other Wyoming rock art sites. "Now we can recognize the sheep paintings," John Greer said. "Paint that is denser than the prehistoric finger lines, and paint smears at the rock projections that are generally low--about the height of a full-grown ewe."
© 2008 by the Archaeological Institute of America