Pigmented Artifacts of Eagle Nest Canyon

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.

Austrailia

An ocher source in the West McDonnell Range of central Australia. Ocher (mineral pigment, derived from earth) is important to many native groups around the world, and it features in the native place names of several place I have lived: Death Valley, California has an indigenous name of Tumpisa (and variations of that name), which is translated as rock ocher.  Similarly, Dubbo, a country town in New South Wales, Australia, is translated as “red earth” and is said to refer to ocher used in body paint

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).

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Amistad National Recreation Area archaeologist Jack Johnson at White Shaman, one of the classic Pecos River style pictograph sites in the Lower Pecos.

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.

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An “early” style painted pebble recovered from Eagle Cave in 2015. Notice the black, fine-line design. Pebble is about 6 cm long.

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.

Flake&FCR

Left: FN33079, found near the center of the rockshelter in a layer dominated by fire cracked rock and ash. A piece of red ocher was found in the same strat. Right: FN33960: This piece of fire cracked rock with pigment on it was found in the same general part of site (PS016) as painted limestone 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…

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FN32916 was found in a fiber-rich (botanical) layer with excellent preservation, near the front of the rock shelter. The strat also contained coprolites, debitage, a core, flake tool, and a quid (chewed fibrous succulent leaf). The reverse side is unpigmented but appears to be pecked, as is typical of a stone surface being prepared as a grinding implement. This artifact is unusual in that it appears to be covered in opaque paint rather than just pigment.

And a second broken limestone rock with pigment along one margin.

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This limestone fragment (FN32955) was found in the same sampling column but slightly lower than FN32916 above, and seems to be the same rock type. Pigment runs along one margin, and is splotchy on the back side. It was also found in a fiber-rich layer with other artifacts, including coprolites, knotted fibers, and a burned antler fragment.

…a flake with a heavily pigmented margin….

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This chert flake with pigment along one margin was found near the back of the rockshelter in a layer with scattered fire cracked rock and charcoal. Numerous other artifacts were also found in the layer from which this artifact came, including hundreds of animal bone fragments, stone tools including a dart point, and, interestingly, a crumbly piece of ocher.

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!

Groundstone

The same fragment of ground stone with red pigment (left) and yellow pigment (right) collected from disturbed deposits in Eagle Cave.

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.

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Zone VI: Into the Eagle Cave Unknown

Zone VI: Into the Eagle Cave Unknown

By Charles Koenig

Since we began excavating the main trench in Eagle Cave in 2014, we have always had some idea of what to expect thanks to the previous work by the 1963 University of Texas excavations.  In 1963, Mark Parsons and Richard Ross spent three days illustrating the north wall of the “Old Witte Trench.”

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Digitized and colorized field illustration of the 1963 Eagle Cave profile drawn by Mark Parsons and Richard Ross. The deep column in the center was added several months after the upper profile was annotated. Many more lenses, layers, and levels were noted on this profile than made it into the simplified, published version below. Original scan courtesy of the Texas Archeological Research Laboratory.

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Version of the profile that appeared in Ross’s 1965 Eagle Cave report. Only the major stratigraphic zones are noted.

Even though they did not record nearly as many “zones” and “lenses” as we have documented strats (units of stratification), we can correlate some of the 1963 stratigraphic zones to 2015/2016 strats because they took the time to illustrate and describe the different layers. Broadly speaking, UT recorded 6 major stratigraphic zones (1-6), in addition to many other lenses and layers within zones. In Zones 1-5, UT recovered a variety of cultural debris (chipped-stone tools, plant and animal remains, and our favorite – burned rock), and the earliest deposits in Zone 5 were dated to 6500-7000 B.C. (Ross 1965). However, they stopped excavating at the top of Zone 6 because it was considered a “sterile layer of yellowish limestone spalls and dust.”

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One of the 1963 Eagle Cave crew members beginning to dig the deep test through “sterile” fill. The white sediment at the man’s feet is Zone 6. View is looking west. Image courtesy Texas Archeological Research Laboratory.

From the outset of our work in Eagle, we have been guardedly optimistic the deposits from Zone 6 and deeper might not be sterile, but simply UT did not excavate far enough to find the next layer of cultural material. In reading the site journal for the 1963 work, we realized the UT crew stopped excavating at Zone 6 not only because they interpreted it as being sterile, but also because they simply ran out of time to excavate any deeper. They did sink a deep test to bedrock at the end of their work, but this was quickly excavated, and from what we can gather, they did no detailed recording or screening of materials that came out of this test. So, as we began excavating into the top of Zone 6 at the end of our last session (the last week in March) we were excited because we knew from that point down we would be excavating into the unknown – the oldest (>9000 years), minimally explored deposits within Eagle.

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South trench in Eagle Cave profile as of 4/17/2016. Top image is just of the orthophoto of the trench, and the bottom is the same image superimposed with our interpretation of UT Zones 1-6 .

First Contact

The first place we excavated into Zone 6 was towards the rear wall in the site. Several of us (Kelton, Justin, and myself) were excavating units to expose a profile section, when Justin uncovered a most surprising artifact: a thick fragment of what appeared to be bison long bone.

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Justin working in Zone 6 (white/yellow in profile).

In addition to the bison bone fragment, Justin also recovered two chunky biface fragments. After the months of anticipation, wondering what we may or may not find, and then to find artifacts and bison bone in one of our first units … we were excited, to put it mildly! As most things go on an archaeological site the bison bone find occurred on almost the last day of the field session, so we had to wait two full weeks before we could investigate Zone 6 again.

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The two biface fragments (top) and sizable bison bone fragment (bottom) recovered in Zone 6 towards the rear wall.

The Trench Floor

Even though we all wanted to jump right in to excavating Zone 6 and seeing what was there, the first thing we did when we got back to work was to devote several days to removing disturbed fill from the bottom of the trench. After completing this dusty, hot, exhausting job we had exposed intact stratigraphy across the entire bottom of the trench. And, by removing the disturbed fill, we exposed more or less exactly the floor of the 1963 excavations into Zone 6.

Before&After_F14

The crew removing disturbed fill from the bottom of the trench (left), and the top of Zone 6 exposed in the bottom of the trench (right).

Once we had the top of Zone 6 exposed across the trench floor, we laid out several units with the goal of excavating down in the trench floor to give us room to work as well as expose profiles on the south wall. However, after only excavating about 10 centimeters below where the UT excavations stopped our excavations slowed dramatically when we started finding bison bone fragments; lots of them.

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The scatter of bison bones as originally photographed in Unit 109.

Unlike the single bone fragment Justin found in the upper Zone 6 towards the rear of the site, Emily, Spencer, and Bryan began exposing dozens of fractured bison bones scattered over a 5 meter area. We knew we had something really cool, and that Zone 6 was definitely not sterile!

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The top surface of Feature 14 (fragmented bison bone scatter) as initially exposed in the Eagle Cave trench floor. The bison bones are slightly more yellow than the surrounding white/yellow rockshelter sediments.

Feature 14

As we continued to expose more and more bone, we realized these bone fragments were all related to one another and likely represent a single behavioral episode. Because of our working interpretation that the bones were fractured and strewn across the extant surface of the shelter in a single event, we gave the bone scatter the designation Feature 14 (the 14th formally designated feature recorded in Eagle Cave since 2014). The feature designation also means we wanted to take special care in how we went about recording the provenience of the bones. To do this we took a series of SfM models and shot in with the TDS many of the bones.

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Intermediate map showing Units 108 and 114 with additional bison bones exposed.

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Intermediate map showing Units 109 and 115 with additional bones exposed. The cluster of rock in the center of the image is Feature 15, a likely hot-rock thermal feature.

We were also very fortunate to have Art Tawater on hand that week as one of our volunteers. Art is a longtime member of the Texas Archeological Society and the Tarrant County Archeological Society, and one of his passions and areas of expertise is zooarchaeology. After the bones were mapped in (piece-plotted with TDS shots) and photographed, Art made a preliminary field ID for the various bones. This was a huge help because none of us (except Black) had any experience with excavating bison bones, let alone trying to figure out what element each bone fragment might be from!

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Art (left) helping Spencer (right) ID and package up bison bone for transport out of the site.

Mapping in the bones and collecting field observations slowed down the removal process, but we wanted to collect as much data in the field as we could so that when our collaborating zooarchaeologists Chris Jurgens and Haley Rush finally get to see the bones they will be well armed for the analysis to begin!  Plus, while the bones were well preserved, they had been purposefully fragmented originally  and some were crushed and cracked by the overlying deposits and did not remain intact upon careful removal.   Our detailed photographic record and Art’s field observations will allow a more complete analysis of the butchering and processing activities that took place on this surface over 9,000 years ago.

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One of the few diagnostic bones we recovered: a proximal left mandible (jaw) fragment from a juvenile bison with deep cut marks on the posterior side. This bone is visible in the Unit 109-115 image above.

Not Just Bone

In addition to the scattering of bison bone, we also found a modest amount of associated lithic debitage and stone tools. If you look closely several of the tools are visible in the above maps. It is telling that most of the chert artifacts appear to be made of only two or three cobbles judging from the matching colors and textures.  This bespeaks a short-term occupation during which only a few cobbles were knapped.

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Two bifacial tools found in direct association with the bison bone of Feature 14. Some of the debitage recovered appears to be the same raw material.

And although there is not the dense concentration of fiber within Feature 14 as in other areas of Eagle, we did recover some very badly decomposing organics.

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A decomposing piece of wood recovered during excavation of Feature 14.

And I also can’t forget to mention the possible hot-rock thermal feature (Feature 15) found at the east edge of the bison scatter, with bones above and below rocks that appear burned!

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Chalkboard shot of Feature 15, a likely hot-rock thermal feature in direct association with the scattered bison bones.

So What Does it All Mean?

We just finished excavating the main portion of Feature 14 earlier this week, so it is really too early to even say the analysis has begun, but we can at least offer up some of our preliminary observations and working ideas. Based on the how fragmented the bones are, we hypothesize Feature 14 represents a bison butchering and processing locale/event within Eagle Cave; possibly that of a single juvenile bison (portions thereof).

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The outline of all mapped bison bones (in black) superimposed onto the initial Feature 14 exposure. The most complete bone–a rib–was recovered at the boundary between Units 114 and 109. All the other bones are fragmentary.

Not only were most of the bones fragmentary, but very few had diagnostic (articular) ends left. In most cases, the field ID was either “medial rib fragment” (~90% of bones) or “long bone shaft fragment” (~8%) of the bones. The fragmented nature of the bones suggests that the people may have been trying to extract bone marrow or render grease from the bones after the meat was removed.

We also have some interesting horizontal distributions of certain artifacts and bones. The areas where we found the highest number of bones with cut marks overlaps with where most of the debitage is clustered. Bones with cut marks plus many flakes indicates this location was where people were cutting bone and/or meat and needing to resharpen their tools. It was also telling to find the relatively few burned bone fragments we found appear to have been concentrated around several thermally altered rocks and scattered charcoal!

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Distribution/highest concentrations of burned bone, bones with cut marks, and debitage overlaid against the bone scatter.

We were also fortunate to recover a projectile point from the same layer as the bison bone. Although not directly associated, this dart point fragment was recovered just to the west of the majority of the bison bones and is made of a very similar dark chert material as much of the debitage.

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From top left: photograph of dart point fragment in situ; both sides of the dart point in the lab; map showing the location where the dart point was recovered in relation to the bison bone.

At the moment we are not ready to officially type the point, but it is a lanceolate, contracting stem dart point fragment that shares several attributes of Angostura points.

Where to from Here?

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Myself, Jack Skiles, and Steve ponder Feature 14 when it was first exposed.

The fact that we encountered Feature 14 as quickly as we did after beginning into the “sterile” deposits of Eagle Cave gives us hope for additional, older, cultural deposits below. We do not know how old the bison bones are at the moment, but we will be sending out radiocarbon samples soon. We have had a lot of fun excavating this intriguing feature, and we look forward to sharing new findings as we make them!

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The location of the Feature 14 bone scatter (linear cluster of yellow dots) and the original bison long bone fragment discovered towards the rear wall. We are excited by the prospects of what we may find as we go deeper into unknown Eagle Cave!