By Emily McCuistion
The sheltered limestone walls of the Lower Pecos Canyonlands are known for their complex and well-preserved pictographs, or painted images on rock. Here in Eagle Nest Canyon several of the rockshelters hold within them both pictographic murals on their walls and portable rock art in the ground in the form of painted pebbles. The focus of this blog piece, however, is neither. Rather, pigmented artifacts without clear intentional design, those having a splotch, wash, or stain of paint or pigment, are the primary subject at hand. These artifacts have the potential to relate the rock art on the walls and in the ground to the technologies of pigment and paint manufacture and use, as well as to the other activities of the canyon’s inhabitants. What follows is a preliminary introduction to the pigmented artifacts we have found in the last three years of the Eagle Nest Canyon Expedition, as well as a partial overview of pigment and paint studies undertaken in the Lower Pecos Canyonlands.
Pigment and Paint
Paint recipes in this region are believed to be comprised of three ingredients: pigment, a binder, and an emulsifier. Pigment is the ingredient that supplies color. The binder is the vehicle for the pigment, giving paint various qualities when drying into a film on whatever canvas is chosen. The emulsifier is a suspension agent. Though it is not known with scientific certainty the exact binding and emulsifying ingredients in the rock art paints of the Lower Pecos, Dr. Carolyn Boyd’s replicative experiments with paint-making from local ingredients may point in the right direction. She successfully used red and yellow ochers as pigments, bone marrow from deer as a binder (compare to oil in oil paint), and yucca root (which contains saponins) pounded and mixed with water as an emulsifier.
DNA studies aiming to reveal what species of animals may have been used in making the binder in rock art in this area have been undertaken on samples from local pictographs. Unfortunately, the studies thus far have not yielded satisfactory and replicable results. On the pigment front, however, our own Charles Koenig and Amanda Castaneda, in conjunction with Carolyn Boyd, Karen Steelman, and Marvin Rowe, have made strong headway in elucidating what some of the pigments used in this region are. More on that below.
Local Rock Art Styles and Canvases
As many of readers of this blog know or have gathered by now, the Lower Pecos Canyonlands is known for its pictographs. Actually, that is quite an understatement- the region is becoming world-renowned for its pictographs. There are four defined styles of pictographs: Red Linear, Pecos River Style, Bold Line Geometric, and Red Monochrome. The styles are believed to be chronologically separated and reflect the culture of different (though perhaps related) groups of people. (For more on rock art of the Lower Pecos see http://www.texasbeyondhistory.net/pecos/art.html and check out SHUMLA’s pioneering rock art studies).
As mentioned, there are also decorated portable artifacts found in excavated contexts. These include the relatively common painted pebbles, rare painted woven items such as burial mats, and rarer-still painted faunal remain such as deer bones, mussel shell and snail shell. Paint would have been applied to other ephemeral canvases as well, such as human skin.
Pigmented Artifacts from Eagle Nest Canyon
During the Ancient Southwest Texas project’s three years of excavation in Eagle Cave, six pigmented artifacts have been identified. Several of these have small splotches of red pigment or paint on them, such as the fire cracked rock and flake below.
Other artifacts have better defined pigmentation and I believe would lend themselves to an interesting study of possible pigment and paint-making technologies. These include a tabular limestone rock with thick paint coating one surface and dripping over the edges…
And a second broken limestone rock with pigment along one margin.
…a flake with a heavily pigmented margin….
A final pigmented artifact from Eagle Cave was found as we were removing slumping and disturbed sediments from the trench floor. The artifact is unfortunately without stratigraphic provenience. It is an interesting artifact nonetheless, a broken oval mano with clear evidence of grinding on several sides. A vertical break through the ground stone artifact has edges/margins that have been trimmed or beveled all the way around the break, resulting in a raised surface. Red pigment is evident on the ground surfaces, and on the raised broken surface it appears that there is faint yellow pigment!
Three pigmented artifacts were also found in Kelley Cave and are described by Dan Rodriguez in his 2015 thesis:
“One bifacial and one unifacial scraper were observed to have red pigment on a single side. The pigment on the bifacial scraper appears to be a congealed paint while the unifacial scraper pigment appears to be an applied powder. Also found in Feature 3 was a burned rock fragment with a red brush mark.”
Other pigmented artifacts have been found in the general region as well illustrated by the online TBH exhibit by Susan Dial on Kincaid Shelter (see Ancient Art: Mysterious Stones and Pigments). This rockshelter located about 50 miles northeast of the Lower Pecos Canyonlands shares strikingly similar painted and incised pebble designs, as well as a number of pigmented limestone cobbles which may have been used to process pigment.
Progress in Pigment and Paint Research
With the exception of the aforementioned ground stone with likely yellow pigment, all pigmented artifacts thus far identified in Eagle Nest Canyon are pigmented red. Paint colors found in the rock art in the Lower Pecos Canyonlands are white, black, yellow, and a spectrum of reds to oranges. Past studies using X-ray diffraction (XRD) on Lower Pecos murals detected specific iron minerals in the pictographs, such as hematite. All pictographs on which XRD was conducted contained a combination of iron minerals. A recent portable X-ray florescence (pXRF) study by ASWT’s Charles Koenig and Amanda Castaneda, in conjunction with other researchers, has yielded interesting insight into what type of mineral pigments these colors are typically associated with. pXRF is a tool for analyzing elements, is non-destructive, and as the name indicates—portable! For these reasons it is a useful tool in identifying elemental similarities and differences in rock art. Koenig et al. found that manganese is the usual pigment in black paints in the Lower Pecos, though charcoal was also used. Red and yellow paints are made with iron-rich minerals, pXRF shows, but may be combined with manganese (either by a natural mixing in the ocher source or intentionally by the artist.) A result of this study was to elucidate the use of manganese in black paints in Pecos River style pictographs, and infer by the absence of manganese in black colored Red Linear style pictographs and un-typed styles, that charcoal was the pigment. Charcoal presence in pictographs also has potential for radiocarbon dating, a method which Dr. Karen Steelman, a collaborating researcher of ours, is currently exploring.
It is an exciting time to be studying Lower Pecos archaeology, as so much interest is being garnered by local research, and as we have many new technologies available which can help us better understand our human past. I feel that we are on the brink of linking the rock art on the walls to the archaeology in the ground, and it will be fascinating to better understand the relationship these pigmented artifacts had to the rock art created here.