The Archaeolympics

By: Bryan Heisinger

Last Saturday while the world was watching the Winter Olympics in Sochi, the 7th annual Archaeolympics sponsored by Texas Parks and Wildlife, Shumla, The Rock Art Foundation, and the National Park Service was taking place in Seminole Canyon State Park. People young and old came out to watch and attend the games in this all-day event. Archaeologists, outdoor enthusiasts, students, and scout troops matched their wits in three competitions: Atlatl, Rabbit Stick, and Friction Fire in hopes to obtain bragging rights for their dexterity, and a chance to win the first place grand prize of a replica Pedernales projectile point.

The first competition to take place on Saturday morning was the Rabbit Stick.  Rabbit sticks are considered a non-return boomerang, and were used by people in the Lower Pecos region for thousands of years for hunting small game. Contestants had three chances to throw a rabbit stick at two strategically placed soccer balls in attempt to knock them off their mounts. Some contenders did great, and others missed all three shots completely. Overall, it was a great warm-up for the next two events.

Rabbit Stick

Jacob throwing the rabbit stick. (Photo courtesy of Shumla)

The friction fire was the second competitive event on Saturday. Archaeologists working in the Lower Pecos have recovered numerous friction fire spindles and hearth boards from the dry rock shelters.  Charles Koenig, Jack Johnson (N.P.S. Archaeologist), Jerod Roberts (President of the Texas State Experimental Archaeology club), myself, and Texas Archeological Society member Robin Matthews, faced off in a race to see who could be the first to create a flame using just two sticks.  As soon as the announcer shouted go, the five of us quickly grabbed our spindles and began to rub our hands rapidly back and forth in a downward motion to get the friction we needed to create an ember. Once the ember began to smoke, we gently dropped it into a bundle of dry tinder and began to blow softly on it until the tinder caught fire. Charles took home first place, as well as a few hand blisters, with an impressive 46 second friction fire.

Friction Fire

Charles, Bryan, and Jerod creating a friction fire. (Photo courtesy of Shumla)

The last competition of the day was the atlatl throw. The atlatl—or spearthrower—was a predecessor to the bow and arrow, and was used by hunters in the Lower Pecos until around 1000 years ago to kill deer and other large animals.  An atlatl is pretty simple, consisting of about a 2-foot long piece of wood with a “spur” attached to its distal end (the spur serves a similar purpose as a nock on an arrow string).  The dart (or spear) fits onto the spur, and then the atlatl is used to propel the dart with much more velocity than you could throw by hand.  For this competition, contenders threw spears at a 3D foam deer target. Points were based on the area of the deer that spear hit. After several long and intense atlatl rounds, Charles once again reigned champion of the atlatl throw.

Atlatl

Charles getting ready to use the atlatl. (Photo courtesy of Shumla)

After the games were complete, awards were presented to the winners and people slowly began to head home. ASWT was happy to take part in the Archaeolympics, and we are are looking forward to next year’s event!

Team Bobcat

ASWT, Shumla, and Texas State’s Experimental Archaeology Club Members. (Photo courtesy of Shumla)

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Winter in the Canyon

By Steve Black and Phil Dering

Eagle Nest Canyon in the winter is a far cry from the summer, when archaeologists usually work in the region.   Instead of stifling back-to-back days over 100 degrees, winter conditions are a lot cooler, obviously, but strikingly varied.  Some days it is sunny and balmy t-shirt weather by mid-day with a highs in the 70s and low 80s; a sheer joy to be alive and working outdoors.  But then windy northers hit and daylight temperatures don’t get out of the 30s or 40s it’s not quite as joyful; but, walking through the canyon is still quite delightful provided you are layered up.  On a recent morning I (Steve) was joined by Phil Dering, an archaeobotanist with advanced training an experience in both dirt archaeology and in analyzing the plant remains found in the dirt.  He is also a paleoethnobotanist, meaning he tries to understand how the people who lived in the canyon for so many generations used and understood the plant world. If the topic interests you, take a look at the online exhibit called “Ethnobotany of the Lower Pecos Canyonlands” that Phil and I put together several years ago: www.texasbeyondhistory/ethnobot/.  To be clear: Phil is the plant expert, Steve is just wordy.

Back to that morning in the canyon.  As we followed a trail leading down that meandered along the base of the cliff we passed through a long and tall, but very shallow, overhang known as Horse Trail Shelter.  Phil stopped to point out two evergreen bushes from the buckthorn family that both held a surprising quantity of mature and immature ‘berries’ (technically fruits).  This is winter, why do we see hanging fruits—these are supposed to be harbingers of summer and fall?  Their presence in early February points to a peculiar aspect of the Lower Pecos: for many desert plants seasonality is strongly conditioned by climate.  Late summer and fall of 2013 were unusually wet, allowing some plants to bloom and put on fruit far later in the year than they would have in “normal” conditions.  While this makes it difficult for the archaeobotanist to make confident seasonality assessments based on charred seeds found in archaeological sites, such atypical years must have been a boon for canyon dwellers.

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Ripe Eagle Nest Canyon condalia berries in early February.

The two kinds of berries also tell another cautionary tale: foragers must know their plants.  The biggest berries of the two, and far more common, were those of coyotillo.  This small, evergreen shrub with deep green, almost glossy and distinctively veined leaves produces green fruit about ½” across that ripens to a dark purple-black color.  While the sweet juicy outer pulp of the dark purple ripe coyotillo fruits might be edible, the large seeds within contain deadly neurotoxins known to have poisoned livestock and people, tragically mostly unsuspecting children.  To learn more read www.texasbeyondhistory.net/ethnobot/images/coyotillo.html.

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Ripe (but still lethal) Eagle Nest Canyon coyotillo berries in early February.

The other berried bush growing in the same area is condalia, a spiny evergreen bush that produces abundant crops of small purple-black fruits readily eaten by wildlife and humans.  Its berries are half the size of coyotillo fruits, and most of them weren’t ripe, but the dark purple almost black ones were surprisingly juicy and tasty.  In fact, birds and other critters had stripped most bushes bare. To learn more read www.texasbeyondhistory.net/st-plains/nature/images/condalia.html. Condalia fruit couldn’t have been harvested in sufficient quantities in the winter for much sustenance for native peoples, but they would have been a quite welcome dietary supplement.  Edible fruit in the winter canyon, who knew?

Back to Horse Trail Shelter.  After we stopped to talk berries, we took a look at several limestone boulders which fell off the cliff many centuries ago.  Long ago native plant processors turned these flat-topped boulders into amazing workstations for grinding, pounding, pulverizing and otherwise processing plant foods, especially seeds, nuts, and beans.  The boulders are covered by unnatural depressions often called “bedrock mortars.”  The tops of these particular boulders had been freshly exposed and cleaned up picture pretty by Texas State graduate student Amanda Castañeda last month during her winter break between semesters. 

3D Model of a boulder with several grinding features in Horse Trail Shelter.

3D Model of a boulder with several grinding features in Horse Trail Shelter.

Amanda is taking on the topic of bedrock features for her Master’s thesis research.  She spent several days working at the site to help develop her documentation methods.  As her photo shows, the bedrock ‘grinding’ features come in different sizes and shapes, some being obvious deep mortars but others include shallow cupules that might have served to hold nuts for cracking?  How does one tell what was being processed in which kind of hole?  Amanda hopes to figure this out through a combination of a comparative study of ethnographic accounts, and thorough documentation of ‘bedrock mortar’ sites in different settings including measuring hole morphology, looking at wear patterns in the best preserved holes, and maybe even getting a residue expert involved.  But that is a story we hope she will tell as her research progresses.

In winter the canyon walls protect the plants a bit better than those in the nearby uplands. Even so most plants are brown and leafless, although others like the berry plants are still green as are the mountain laurels.  Most winter days the birds are not as active as they are during other parts of the year, but on warm calm days the ravens, wrens and others make themselves known.  On a recent afternoon Steve hiked back down into the canyon after the dig day was over and enjoyed the solitude, soaking up the winter sun, listening to the birds, and watching for movement.  You can see the topography better sans leaves, and the sounds seem to carry farther on calm, crisp days. 

Some winter days are less enjoyable.  Two weeks ago we experienced three overcast and windy days in a row that did not get above the low 40s.  No matter how many layers you have on, after hours of cold wind swirling up the canyon and down your neck, clutching cold metal tools, and kneeling in one spot for too long, winter sinks into your bones.  You even catch yourself thinking fondly of a hot summer day. Happily the bone-cold days aren’t constant and most afternoons are quite tolerable. 

We do find ourselves repeating the observations and speculations each generation of Lower Pecos archaeologists has made about rockshelter orientation.  Eagle Cave gets early morning sun, but by noon it is back in the shadows, and the rockshelter (being wider than it is deep, it really isn’t a cave) seems to catch the wind no matter which direction it is blowing from.  Skiles Shelter, on the other hand, is in full sun from late morning onward – we have to use shade tarps and are down to t-shirts on many afternoons when elsewhere in the canyon requires additional layers.  These experiences lead us to speculate – “this shelter must have been a winter favorite,” or “no way they would have lived here in the winter” and so on.  But how do you actually find hard evidence of seasonality when sometimes even the warm weather indicators are ripe and harvestable in the winter?

For us, the 2014 winter in the canyon is a lifetime experience we will likely tell glowing stories about for the rest of our careers.   Then again, at day’s end we go back to camp and enjoy a hot shower, a good meal, and a warm bed.   Those who spent the winter of 2014 B.C. here might not have been quite so enthused. 

Earth Oven: Searching for the Trifecta

by Jake Sullivan and Brooke Bonorden

Let me begin by explaining what an earth oven is. An earth oven is a cooking technology that has been widely used in the Lower Pecos for thousands of years. To create an earth oven, a pit is dug into the ground and a fire is built. Large stones are placed amongst the flames; these stones retain the fire’s heat and become the oven’s heating element long after the fire has died out. Next, a layer of packing material is laid across the hot stones in order to insulate the food from direct heat and provide moisture. Prickly pear pads work great for this and can be found in abundance in the Lower Pecos. The food load, the trimmed hearts of the desert succulents sotol and lechuguilla, is placed on top of the packing material followed by another layer of packing material. The oven is then capped by a thick layer of earth to prevent precious steam heat from escaping. After cooking for at least 36 hours the food is ready to be unearthed and consumed.

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Processing sotol for an experimental earth oven.

The baking process turns the complex carbohydrates within the plants into sugar. These plants also contain a chemical called saponin, which is inedible in its raw form but is rendered harmless by the cooking process. I can tell you from experience that baked sotol doesn’t always taste good, but it is a reliable food source in a harsh and highly variable environment.

As part of the ENC project, one of the research topics we are interested in is calculating how much earth oven processing occurred at different sites, i.e. how many times each earth oven locale was used. Fire-cracked rock (FCR) is the most common remnant of an earth oven cooking facility found in an archaeological context. In the field we have been sizing, counting, and weighing the FCR that we find in each layer of our excavation units. What we find most often, and what makes up the majority of the enormous talus slopes in front of the shelters, are FCR that have been discarded after multiple heating events and are now too small to store heat efficiently. However, in order to find out how much earth oven processing has occurred we need to do more than just count and weigh the burned rock coming out of our units. We are planning to do this by trying our hand at some Experimental Archaeology.

One of the challenges for archaeologists is understanding how the things you find in the ground are related to human activity—especially when it comes to burned rocks.  So, we carry out different experimental archaeology projects to help us figure out what burned rocks in the ground might represent. Collectively, we have built many earth ovens to demonstrate the plant baking process from start to finish. However, beyond demonstrating how local edibles were processed by those who occupied the rockshelters we work in, we did not collect any real scientific data to help us answer questions related to earth oven processing.  So, we are planning a series of long-term experiments by creating our own earth ovens. We hope to document the number of plant baking episodes necessary to significantly reduce the size of our heating elements (rocks) to the size of the FCR that we are finding in burned-rock middens (BRM) throughout the canyon.

On Thursday the ENC crew searched the property surrounding the Shumla campus for a new site for our upcoming experimental earth oven. When seeking out the new oven location we tried to keep in mind the qualities that would have appealed the natives who were using this cooking technology for their survival. The vast majority of optimal locations we saw while traipsing through the always-thorny local shrubbery were already occupied by evidence of prehistoric plant baking – fire-cracked rocks. What makes a location optimal is its proximity to the trifecta: fuel, food, and dirt. Native peoples would have tried to find a location that was relatively close to all the fuel, food, and dirt they needed to construct and fill the oven so they wouldn’t have to expend extra energy hauling in supplies. Eventually we found a pristine location untainted by archaeological evidence. 

In anticipation of building our first earth ovens in the new locale, our first task is to collect phosphate samples at the recommendation of our geoarchaeologist colleague Ken Lawrence.  Phosphorous (or P) analysis looks at the phosphate that accumulates in sediment by many aspects of human activity. What’s great about phosphorous is that it decays very slowly through geologic time, so it’s a reliable element for targeted study. Our goal in using this method is to analyze how quickly and at what levels phosphate will accumulate in sediment that has been manipulated by plant processing and baking. To accomplish this we will be taking initial baseline samples at the oven location, and then Ken will come back and collect more once we have started processing.  This is important to archaeologists because it gives us another way to interpret the intensity of the plant processing that occurred at local sites. By understanding how much earth oven processing occurred, we will be able to compare how many times different sites were used, and gain a better understanding of how people moved across the LP landscape.

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We can’t believe how good it tastes!

 In a few weeks we will tap the trifecta and start building ovens and monitoring the cracking rocks.  We will also be following a pattern that native peoples must have relied on – in the winter, lechuguilla and sotol are among the few potentially edible plants that can be harvested.  

Low Impact-High Resolution: Using the Strat System in Eagle Cave

By Charles Koenig

Within archaeology, and certainly in several of our blog posts, you will hear the term stratigraphy.  So, what exactly do we mean by stratigraphy?  Within any archaeological site there are different layers of stuff—artifacts, rocks, different kinds of dirt or sediment—and each of these layers may contain different things from the layers above or below it.  We consider each layer to be a stratigraphic unit, or strat for short.  In some cases these strats can be the result of human activity (e.g., making fires) or when a river floods and leaves behind a deposit of sand and clay.  All things being equal, over time strats build upward and older strats are continuously covered by younger strats.

A photograph of a layer cake borrowed from Google (right), and a hungry archaeologist's version of the same cake (right).

A photograph of a layer cake borrowed from Google (left), and a hungry archaeologist’s version of the same cake (right).

In other words, imagine a triple-decker cake as a substitute for an archaeological site.  This cake has chocolate cake on the bottom, strawberry in the middle, and white cake on the top.  Between each level of the cake are layers of frosting.  When you cut into this hypothetical cake, you will be able to see all the different layers, and to an archaeologist each layer of this cake (e.g., the chocolate, strawberry, and white cake as well as the different frosting) can be considered a unique strat.  Actually, archaeologists even refer to very distinct ideal layering within a site as “layer-cake stratigraphy” (a classic example of “layer-cake” stratigraphy from an archaeological site in the Lower Pecos is Arenosa Shelter, which you can learn more about here: www.texasbeyondhistory.net/arenosa).

When you study the different strats within the cake, you can start determining the order in which the cake was constructed.  For example, the chocolate cake layer at the bottom is the oldest part of the cake, and then the strawberry frosting was spread on, and so on).  As you study and record how the different cake and frosting layers were placed onto the cake, you begin to understand how the complete cake was created.  Understanding how a site (or cake) formed is what archaeologists call site formation processes.

Now, to jump back to stratigraphy in Eagle Cave.  One of the tragedies about Eagle Cave is when the University of Texas wrapped up their excavations in 1963, they left all of their excavation units open (as did the Witte Museum in 1936).  Over the past 50 years all the walls have collapsed, but there are still large depressions where the units once were.  When we (Steve and Charles) began writing the research design for Eagle Cave, we knew we would be able to take advantage of the existing units to expose any intact stratigraphy.  However, we knew from previous excavations at Eagle Cave the stratigraphy is anything but layer-cake—dozens of thin, hard to see strats mixed in with thick, rocky strats all churned up by rodent burrows and human-dug pits—in short, extremely difficult stratigraphy to carefully document and understand.  So, the big challenge became: once we expose the stratigraphy, how should we document and sample the complex layering within the site while minimizing the overall impact our project has on the remaining intact deposits?

What we decided upon was to use a version of Steve’s Strat System from his work in Belize in the early 1980s, and came up with the motto, “Low Impact-High Resolution,” meaning we want to learn as much as we can while doing the least damage to the site.  To go back to our layer-cake analogy, imagine you are a food critic and you have 10 of your closest food critic friends coming to sample every layer within the cake tomorrow.  But, because the cake is so delicious you need to save enough cake for 10 more food critics to sample the cake every 50 years for the next 10,000 years (fortunately this hypothetical cake never rots).

Over the next 6 months (and likely on and off for several years) we will be documenting the stratigraphy of Eagle Cave at dozens of different spots.  All of these exposures will be in areas which have been previously excavated or dug into by critters or artifact collectors so we are only damaging small portions of the intact stratigraphy.  We are calling these Profile Sections.

Steve and Tina Exposing and Cleaning PS001 prior to strat identification and subsequent sampling

Steve and Tina Exposing and Cleaning PS001 prior to strat identification and subsequent sampling

Yesterday we documented and began to record our first profile section: PS001.  The location of PS001 was selected because there was a large animal burrow and adjacent backdirt pile, and we could just make out what appeared to be intact stratigraphy above the burrow.  The burrow angled downward into the deposits (and can be seen toward the bottom of the profile), but by cutting back only a few centimeters above the burrow we were able to expose ~60 cm tall profile section. We were very surprised to encounter intact stratigraphy only a few centimeters below the ground surface, so we are very encouraged to begin exposing and documenting additional Profile Sections.

Image of PS001 exported from ArcGIS. A 3D model of 60 photographs was used to produce the image.

Today we began documenting the different strats in PS001, but those descriptions are incomplete.  When we begin our sampling we will likely take small matrix samples out of each identified strat, and screen the material through nested geologic sieves.  We will then be able to coordinate with our collaborators (like Phil Dering and Charles Frederick, among others) to begin analyzing all the different material in each strat – sediment, plant parts, animal bones and so on.  This is where High-Resolution comes into play.  We want to systemically sample each strat individually so we can gain a more detailed understanding of when and how the site formed over time, how the site was used during different time periods, and use the data to address many other questions.

Feel free to check out the 3D PDF of PS001 at the Link below!

3D PDF of PS001