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Carol Diaz-Granados, Ph.D., research associate and lecturer in the Department of Anthropology in Arts & Sciences, has doubled the known number of Missouri's native American rock images --petroglyphs and pictographs --in the state's first systematic survey of prehistoric "rock art."
Rock art refers to both petroglyphs (carvings in stone) and pictographs (painted or drawn images).
Diaz-Granados' findings have been published in a book titled "The Petroglyphs and Pictographs of Missouri," which documents 134 sites of rock art images. Only 65 to 70 were known before she began her work in 1983.
"I personally prefer the term 'rock images' or 'rock graphics,' because I believe they are more about communication than about art," said Diaz-Granados, who has made petroglyphs and pictographs her life's work. "The Petroglyphs and Pictographs of Missouri," which was based on her two-volume dissertation, contains 86 drawings and 36 photographs and was published by the University of Alabama Press this spring. Diaz-Granados' husband, Jim Duncan, is listed as a co-author because of his help in the field and contributions to the section on mythology.
Petroglyphs and pictographs are found all over the state, according to Diaz-Granados. "Where there is rock," she said, "you usually find rock art." Petroglyphs are found on exposed boulders, bluffs, near springs, and usually on dolomite, but sometimes sandstone, limestone or granite. Pictographs are almost always on sandstone and usually in slightly protected areas, such as under a bluff overhang or inside a shelter or cave.
"People don't think of Missouri as being a Mecca for rock art, but we do have an unusually large number of sites in the eastern half of the state," Diaz-Granados said. "This is mainly because of the heavy activity by Native Americans around both the Mississippi and Missouri rivers, along with the influence from Cahokia across the Mississippi from what is now St. Louis."
Charles H. Faulkner, archaeology professor at the University of Tennessee, said in a review of Diaz-Granados' work: "This book should be a model for rock art research techniques in the Eastern Woodlands. Diaz-Granados and Duncan's work breaks new ground in style/motif analysis, methodology, and relationship to Native American mythology in studying these archaeological phenomena."
Archaeologists have typically stayed away from pictographs and petroglyphs, Diaz-Granados observed. "I think this is primarily because they are so hard to date," she said. "But these images are as much a part of the archaeological record as any other artifact."
Typically researchers have determined rock art dates by comparing symbols of objects to the actual artifacts that are found in excavations. Recent advances, by a group in the chemistry department at Texas A&M University, have enabled researchers to extract a small amount of pigment and determine the date with accelerator mass spectrometry. At this point the technique is used only for black pigments containing charcoal.
The Texas A&M researchers tested three of the Missouri sites. Their dates were determined to be around A.D. 1000, which coincides with dates based on the related diagnostic artifacts.
As part of her analysis of the data, Diaz-Granados classified designs into about 50 typical motifs and analyzed the locations and patterning of these designs throughout the state.
Among the most common images in Missouri are the bird, foot, serpent, quadrupeds, anthropomorphs and abstract designs. The three most typical motifs are the bird, the serpent and a variety of quadrupeds, such as deer and elk. Diaz-Granados said that this finding could be explained by the American Indian belief in a cosmos divided into three distinct but related worlds, the upper world (symbolized by the birds), the middle world (represented by the quadrupeds) and the lower world (the snakes).
Because rock art is primarily above ground, it is particularly susceptible to vandalism and weathering.
"The recording of these fragile prehistoric documents, as with any endangered site, should be a priority in each state's preservation efforts," Diaz-Granados said.
Diaz-Granados returned to school for a Ph.D. when her own children were grown. She noted that from 1989 to 1991 she and her four sons were all in college or graduate school at the same time. She first became interested in rock art in 1983, when, as a graduate student in archaeology, she was engaged by the Missouri Department of Conservation to write a report on the petroglyphs at the Rocky Hollow site in Monroe County.
"It was a lovely site, one of the top three in the state," Diaz-Granados said. "It is located in a small canyon with a river running through it and petroglyphs on both sides. When I saw the site I fell in love with rock art. I had no idea before I did my research project that Missouri had so many of these fascinating images. They are definitely worthy of study and preservation."