P.I. Eyes Eagle Progress

By Steve Black

Over Spring Break last week I spent several days at Eagle Cave eying progress. The 2015 season is the first time since the inception of the ASWT research program in 2009 that I’ve worn only one hat, that of principal investigator (P.I.). Until this season I have also been the field director, meaning I was responsible for making most of the day-to-day strategic field decisions, as well as setting the overall research agenda, organizing the endeavor, and arranging funding and logistics. And so I found myself in Eagle Cave on Thursday, March 20th looking at the ongoing investigations with field-fresh eyes.

I have learned from experience one of the most important things to have at any archaeological site is a comfy chair for the PI to sit in and enjoy the view.

I (Charles)  have learned from experience one of the most important things to have at any archaeological site is a comfy chair for the PI to sit in and enjoy the view.

Below is what I wrote in my field journal as I sat looking out from the back of the shelter in an almost comfortable camp chair. Other than minor spelling and punctuation edits and the added contextual explanations in italics, this is verbatim.

“Work continues apace in Eagle. The crew is now a well-oiled excavation machine—six different exposures—from closest to back wall: Bryan excavating Unit 50 in Strip 3, exposing Feature 8; Tory excavating Unit 49 which spans Strips 3 + 4; Emily strating PS13 in Strip 4; Kevin Hanselka strating PS12 in Strip 7; Lindsay cutting back 2nd step in Strip 8; and Larsen and Elizabeth excavating Unit 48 in Strip 9. Wow! The Strategist—field director Charles Koenig­—moves back and forth directing the symphony, making strategic decisions, keeping track of who is doing what, looking over shoulders.”

Kevin Hanselka (left) and Emily both were identifying and describing strats (individual stratigraphic layers) within PS12 and PS13, respectively.

Kevin Hanselka (left) and Emily both were identifying and describing strats (individual stratigraphic layers) within PS12 and PS13, respectively.

“Bryan now an old hand—more confident and capable—Charles assigns him tasks requiring greater independence and/or leading the interns to accomplish a given task.” [Bryan Heisinger served as an intern in 2014 and promoted to staff archaeologist this season.]

ASWT Staff Archaeologist, Bryan Heisinger, excavating Feature 8 - an earth oven central depression

ASWT Staff Archaeologist, Bryan Heisinger, excavating Feature 8 – an earth oven central depression

“Larsen also more confident and able—building on short season. [Matt Larsen was at student volunteer for final six weeks of 2014 season; he graduated from Texas State in December and this season he is a regular intern.] Today he also has field journal duty.” [The crew takes turns keeping the daily field journal.]

Larsen delicately excavates through a fiber/FCR layer.

Larsen delicately excavates through a fiber/FCR layer.

 

“Tory handles TDS well—she set it up at right height for level or slightly downward shots, but must get on her tip toes to shoot down to the lower units. She is primary TDS operator this session. [Victoria Pagano is a 2015 intern and has just been accepted into the graduate Anthropology program at Texas State starting in the fall. TDS = total data station, the machine set up over a datum that gives us precise 3D coordinates for any targeted spot. A different core crew member serves as the go-to TDS operator for each 3-4 week field session. ]

Tori running the TDS - "shooting" in everything from strats to matrix samples to coprolites.

Tori running the TDS – “shooting” in everything from strats to matrix samples to coprolites.

 

“Emily assigning FNs in tent—flurry of requests from team members, some for Strats (she went to assign her own FNs for PS13, but wound up issuing FNs for others), some for Unit Layers, Spots, and Matrix Samples.” [Emily McCuistion is the final 2015 intern. She has defined the Strats or stratigraphic units for Profile Section 13 and assigned each Strat a unique Field Number. We also assign FNs for each small Spot sample of characteristic matrix for each Strat, and all other types of samples we collect. Our documentation system requires precise book keeping and the FNs make it possible to link one kind of data to another. We have a tent set up at the back of the shelter on the downstream end where we keep the laptop used to assign FNs and various equipment we try to keep out of the dust.]

“Kevin Hanselka volunteering today—fresh eyes with archaeobot lens—he was assigned to define strats in profile section with numerous fiber lenses. He spots various new things including a dart point with its tip sticking directly out of the profile. Charles tries out ideas on Kevin—good give and take. Kevin often mentions what he learned from previous experience or from an article he has read. “Ok, so we have agave lechuguilla and …” [Kevin earned his Ph.D. at Washington University at St Louis where he studied under Gayle Fritz, one of the leading archaeobotanical scholars in North America. His dissertation research was on plant remains from the Sierra de Tamaulipas rockshelters that famed archaeologist Scotty McNeish excavated the late 1940s.]

Kevin telling the crew about different plant parts they are finding.

Kevin points to examples of different plant parts exposed in profile. TxState graduate student Amanda Castaneda looks on.

“This is why we really appreciate our visitors and volunteers—fresh eyes and questions. SLB joins a discussion of fiber production that Kevin links to a fellow Wash U grad student who based her dissertation research on ethnographic accounts from the Eastern Woodlands—weaving and basketry done in rockshelters + houses because in open the fiber dries out too quickly. Were such weaving activities also emblematic of LPC shelters? Related, the whole issue of H-G intensification—managing landscape resources such as lechuguilla fields. Lech harvested for fiber, beverage and food. Could possibly trim leafs without harvesting bulb. But wouldn’t the heavy use for food be a ready source of fiber?”

“Elizabeth and Lindsey are a bit more tentative—the latter now has some ENC experience, the former new to area, also here for Spring Break. Chas assigns both to work on outer strips where we are working to cut back to intact layers.” [Elizabeth Jaroszewski graduated from TAMU and was just accepted as a TxState graduate student beginning in the fall. Lindsey Vermillion is a TxState senior who volunteered during last six weeks of the 2014 season and has proven to be a quick learner and hard worker.]

Lindsay and Elizabeth screening sediment from their units, while the rest of the crew works in the background.

Lindsay and Elizabeth screening sediment from their units, while the rest of the crew works in the background.

“This is the balancing act the Strategist must juggle—who has the skill set for a given task—and how to keep everyone busy productively? Long trench with different steps, strips, units, and profile sections makes this possible. Core crew can now do everything so he [Charles] lets them follow through, intermittently or continuously, from strip to unit to PS, giving them a sense of ownership and taking advantage of specific experience/familiarity w/ any given area.”

[In laying out the “Strat System” in our 2013 Eagle Nest Canyon research plan I used the term “Strategist” for the position that archaeologists of my generation usually called “Field Director.”  And although in the intro to this post I claimed to have worn the hat of field director/strategist until this season, I have shared this role with my graduate students as they have taken charge of certain investigations as part of their thesis research projects.  I am sure I have intruded into their decision making rather more than was helpful at times.  But making the strategic call is one of the things I love most about being an archaeologist and I’ve sometimes found it hard to relinquish strategic control.  It does my heart good to watch my former graduate student Charles lead the charge with aplomb.]

“Sounds—conversations in various spots across EC—some of unrelated experiences, like those told at the Screening Station. Some work related—back and forth on TDS, FN assignment. Above ideas discussions. Charles explaining steps and making sure forms are filled out… ‘Larsen this evening I’d like you to …’ iPod with jazz playing softly in background…. ‘Looking.’ ‘Shooting.’ ‘Got it.’ “Next is 329 and 318….’ Footsteps, some loud some muffled….. Scrape of trowel hitting FCR….. Soft brushing sound emanates from billowing cloud of dust. Those wearing dust masks have muffled voices—I can’t understand, but crew seems to follow easily—practice and younger ears.”

Work scene on March 20, 2015.  Field director Charles takes a break shoveling out disturbed matrix while keeping an eye on the crew.

Work scene on March 20, 2015. On far left field director Charles takes a break from shoveling out disturbed matrix while keeping an eye on the busy crew. On the far right Elizabeth holds a reflector board to improve the lighting on the area where Bryan is taking yet another round of SfM images.

[Added the next day] “Strategic decisions are often tough—no clear-cut best way when dealing with very complex stratigraphy—pits dug through pits, fill vs. primary thermal features, hard structure (FCR layers and concrete-like ash conglomerates) vs. soft ash and softer burrow fill, plus the many exposure faces (of strips, profiles and units).  With SfM we can adapt and change our minds, knowing that we can reassemble/stitch [the 3D models]. Still, flexibility isn’t easy.  Use of Strat System and FN essential. Record Keeping critical. ‘Tis a challenge!”

And that is the Eagle Cave 2015 progress as eyed by this P.I. I will admit that as I started to write most of the above in my field journal it dawned on me that ASWT blog readers might appreciate a look at the excavation scene at Eagle Cave. I had realized that at the moment I was superfluous – most of the crew knew what they were doing and Charles was doing a marvelous job directing the scene. I could sit back and take it in as a participant-observer.

A competent archaeological crew intelligently and diligently investigating a fascinating rockshelter in a remote corner of the natural and modern world is indeed a joyful thing for a principal investigator to behold. I’m already looking forward to my next trip.

Adventures in the Ancient Lost City of the Rodents

Larsen hard at work.

Larsen toiling away in the Mines of Mole-ia.

By Matt Larsen

Hey y’all, I’m writing today about burrows – but I’m talking packrats not pack animals. If you don’t remember me, my name is Larsen, and I am a recent graduate of Texas State, and this is the first long-term archaeological project I have worked on. One of the things that surprised me when I first started excavating out here is the large number of burrows we encounter. The burrows range from small and winding to large and cavernous. In some places it feels more like we are exploring some vast ancient underground city created by small creatures. Was it miniature Yeti, a.k.a. Littlefoot? Nope, it’s burrowing rodents.

The focus of our Eagle Cave excavations this season is the south face of the trench originally created by the Witte Museum in the 1930s and widened by the University of Texas at Austin crew in the 1960s. When we began excavating we were attempting to cut through the surface disturbed material to intact deposits. As Emily and I excavated our first unit, we had to discontinue cutting south into the trench face because we ran into an extremely large burrow, which we started calling the “Badger Burrow”.

Charles attempting to curl up in "The Badger Burrow".

Charles attempting to curl up in the “Badger Burrow”.

In this same area, I was excavating back the face of the unit and came upon a burrow with a tail sticking out of it! I was somewhat startled by this as we had been joking about cutting into a badger burrow and having an angry badger jump into someone’s face. At first I thought it was a snake, but then I realized it was a hibernating lizard. I gently removed the lizard and moved it to a place where it would be safe from animals and archaeologists.  These burrows are good examples of today’s blog topic: bioturbation.

What is Bioturbation?

Bioturbation is the term archaeologists use for any disturbance of the ground by living things. These include plants and tree roots, rodents, reptiles, insects, worms and any other organism that delves into the ground. Bioturbation is an issue all archaeologists face in some form or another. So, how does bioturbation affect archeological digs?

Bill Murray isn’t the only one concerned with burrowing animals. Archaeologists are concerned with bioturbation because it alters the archaeological context (see Where Context is Crucial). As organisms move through the earth they can affect the archaeological record in several ways. First, and most obviously, bioturbation changes the stratigraphy. Roots and especially burrows move dirt around in the earth. Dirt that was down deep is brought up, dirt that was near the surface is carried down and earth can be moved all over as animals backfill their own burrows. In a Canadian study of pocket gophers it was estimated that, if one gopher at a time lived in a 10x20m area and digging activity remained constant over 200 years, approximately 25 metric tons of earth would be moved!

A pocket gopher.

Hello, Mr. Pocket Gopher, it’s your friend Mr. Squirrel.

Burrowing animals often move artifacts up in the ground. The gophers, for example, make burrows about 6-7cm wide. Anything they come across that is less than 6-7cm, such as tools or projectile points, will be carried by the gopher out to the surface or into a side chamber of the burrow.

Bioturbation can also cause artifacts to move down farther into the ground. Burrowing by animals can undermine artifacts, even artifacts much larger than the animal (like a grinding slab for example), which allows them to sink down in the earth.

Burrowing animals also have a tendency to bring things in to their burrow, such as food or nesting materials. This means that some objects may seem to be deposited by people, but in actuality were brought into the ground by animals.

The movement of earth and artifacts through bioturbation requires archaeologists to understand that just because an artifact is found in a certain stratum does not mean it was originally deposited at the same time as that stratum. It also means care should be taken in establishing an age for a stratum or an artifact.

The destruction of a stratum or the movement of artifacts are negative aspects of bioturbation, from an archaeological standpoint.  Bioturbation can also, however, be a positive thing. Bioturbation can be a tool an archaeologist uses to study the past.

Positive Aspects of Bioturbation

The organic things brought into a burrow can tell us a lot about the past. The plant and animal remains preserved in a burrow inform us about what kinds of plants and animals lived in the area at a certain point in time. Because plants and animals like certain kinds of conditions, such as temperature and precipitation, we can extrapolate what the climate was like in the area at that time as well.

I recently learned of another positive aspect of bioturbation while listening to the radio. There was a story about two archaeologists, one in England and one in Denmark, who were using moles to gather archaeological data. Both were analyzing things brought to the surface by moles at protected sites where the archaeologists were not permitted to conduct an excavation themselves.

A mole.

A mole (happily, not present in Eagle Cave!).

In Viborg, Denmark, Jesper Hjermind studies what moles dig up at the site of a medieval fort. The moles often bring up artifacts and pieces of brick. By analyzing these objects, Hjermind is able to determine the location of buildings at the fort. If there are many objects at a molehill, then that is where a building is underground. The story can be found at: http://cphpost.dk/news/moles-digging-in-the-name-of-archaeology.12859.html .

At the site of a Roman barracks known as Epiacum in Cumbria, England, Paul Frodsham is also not allowed to excavate because the site is protected. He sifts through the tailings at molehills to find artifacts from Roman times. While this does not give him a full picture of the archaeology at the site, it allows him at least a glimpse. The story can be found here: http://www.bbc.com/news/uk-england-cumbria-22363936 .

What all this tells us is that bioturbation is a fact of life for an archaeologist and it can be either a help or a hindrance depending on how it is approached.

Bioturbation at Eagle Cave

Common bioturbators of the region.

Common bioturbators of the Lower Pecos region.

So what does bioturbation mean for us on site in Eagle Cave? How do we recognize it? How does it hinder us and how does it help us?

At the surface in Eagle Cave, the main agents of bioturbation were sheep, goats, and people. Eagle Cave was used in the early 20th century as a convenient place to pen sheep awaiting shearing in the pens atop the cliff. This means that the surface was mixed up by their milling about and is heavily disturbed. Further, people visiting the site for nearly a century have picked, plucked, and scratched at the surface (and deeper) of Eagle. We surmise the strata from the Historic through the Late Prehistoric eras – the layers at the “top” of the shelter profile – are nearly completely destroyed.

When we excavate at Eagle Cave, we first clear away the disturbed surface layer to get to the intact deposits underneath. As we dig into these intact strata, the main agents of bioturbation are burrowing animals such as rodents, lizards, and insects. The burrows we find range from very small insect burrows to extremely large mammal burrows. Most burrows are from rodents and are, on average, about 7cm (~2-3 inches) in diameter. We are able to distinguish burrows from intact material in several ways.

PS010 is a nice example of different burrow sizes and shapes. Note the excellent color contrast in the central burrows.

PS010 is a nice example of different burrow sizes and shapes. Note the excellent color contrast in the central burrows.

First, we use visual clues to identify burrows.  We often have clear layers (e.g., alternating white, black, and gray bands of ash, charred fibers and the like), and whenever there is an interruption in the strat from a burrow, the contrasting colors stand out, like in the above photo.  We also often see nesting material in the burrow matrix, grass or straw, and sometimes there are pockets of cached seeds. In modern  burrows, we often find sheep and goat dung mixed in as well.

Plan view of Emily excavating a burrow.

Plan view of Emily excavating a burrow.

In plan view (looking down on a unit from above) we can often see the burrow as a linear track extending across the unit. In profile view (looking at a vertical surface from the side) we often see burrows as either a circle of material, a hole, or as a linear disturbance extending across a profile face.

Archaeological excavation is not just dependent on visual cues, like color changes, but is also an extremely tactile endeavor. When we hit a burrow, it usually feels very different under the trowel from the rest of the stratum. Most of the time the burrow material is exceptionally loose; the trowel just sinks right in several centimeters without any pressure applied by the excavator at all.

Bryan excavates a rodent metropolis.

Bryan excavates a rodent metropolis.

The deposits at Eagle Cave often have burrows in them, and it can be extremely frustrating for an archaeologist to work with strata that are more burrow than intact. When we began excavation this season, we were excavating near the back of the shelter and we had to move a lot of earth before we found intact deposits. As we were cutting back the trench face we finally had to stop because we came upon a burrow nearly a meter across, the aforementioned “Badger Burrow”. We are no longer excavating from this area (the far right unit in the photo to the right) to the back of the shelter because it is all the backfilled trenches of the excavations in the 1930s; which just goes to show that archaeologists can be proficient bioturbators as well!

While at times frustrating, the disturbed and burrow material does not go to waste. We screen samples of these disturbed sediments on-site and use the artifacts we find for educational purposes here and at Texas State University. We often find interesting artifacts within the burrow material, including two large bison teeth this season.

Bodilly, the Bioturbation Hedgehog, promotes awareness of bioturbation amongst archaeologists.

Bodilly, the Bioturbation Hedgehog, promotes awareness of bioturbation amongst archaeologists.

So, while these artifacts have no clear archaeological context, they do clue us in as to the types of artifacts we should find. And we retain rare items (like a mussel shell pendant we found this week). They are also exciting finds that keep us motivated and in good spirits!

In summary, bioturbation is a part of nearly every archaeological excavation. It is important for researchers to understand the role bioturbation plays in the formation of an archaeological site so we can accurately interpret the data from a site. Although bioturbation is often frustrating, it can also be helpful to an archaeologist if used as another means of gathering information. We try to keep this in mind here at ASWT when we come upon an area that is more burrow than strat and makes us feel more like rodentologists than archaeologists.

Archaeology in a Whole New Dimension

By Victoria Pagano

Hello again, it’s Victoria here to tell you that I’m excited. Excited about the work we’re doing out here in Eagle Cave and with the ASWT project as a whole. Now this is not to say that I wasn’t enthusiastic when I first found I would get a chance to intern in an amazing place, with knowledgeable people, learning and doing great new things; but, I’m writing now with a little training under my belt as to the way things work and and a better understanding of how absolutely fantastic it really is.

10574530_843982255626142_5890745378201517667_n

Okay, this isn’t at Buenavista, but it is one of the sites that is worked on by the project. Mighty “El Castillo” at Xunantunich, just one example of the architecture and archaeology to be found in Belize.

Before ASWT

First, I would like to tell you a bit about my first and only field work in archaeology…just to offer a bit of perspective. I was unbelievably lucky to work in Belize. A beautiful country full of cultural and ecological diversity– not to mention the incredible historical and archaeological richness it holds as well. The project was based in the Mopan River Valley, studying the ancient Maya sites of San Lorenzo, Xunantunich, and Buenavista del Cayo. My work was focused at Buenavista, a mid-level city center with plazas and stone structures that had been reclaimed by the jungle.

Belize

That’s where I worked, Buenavista del Cayo. Just down the river from Xunantunich and many other archaeological sites.

It was in Belize that I learned basic excavation procedures:

Step 1: Find somewhere you want to excavate and establish an excavation unit. This includes (for most) establishing a permanent datum, laying out the unit, and taking starting measurements.

Step 2: Establish your excavation protocol. Are you going to follow natural breaks in the stratigraphy, or are you going to use an arbitrary measurement to create your strata, lots, layers, etc. You’ll probably want to sketch and photograph the starting and ending surfaces, too, as you work your way down.

Step 3: You find something really cool in the floor or wall of your unit… a hearth, post-hole, projectile point, a body, etc. — you decide you want to make sure this is in your notes (hopefully you are taking notes, good notes), so you need to take additional steps.

Step 4-6: You need to 4) Take photographs– with a scale and some indication of direction 5) Map it i.e. create a drawing by measuring to and from objects in your unit to an established point or points, like a sub-datum. This will yield a plan or profile map with detail as to where your find is and where everything else in your unit is in relation to your find. Detail, detail, detail!  Depending on how precise you want your map to be, if you have help, and your level of OCD, drawing a map can take anywhere from minutes to hours.  6) Take more notes of the object’s location, this may include a GPS point that you tie to your datum later, or measurements that you will use to associate the object’s location relative to the datum.

Step 7: You’re probably pretty tired from all those steps you took to draw your unit. You need a nap, but chin up, you established your unit today AND you found something! Hopefully your notes are good, you read that compass properly, and you’re mapping skills are adequate enough that your map doesn’t simply look like a box with a few misshapen circles, squiggly lines, and a triangle.

Now I have nothing against all those steps (the old fashioned paper and pen method works), but there is always room for improvement.  So why is it I am so ecstatic to work in a place where there isn’t monumental architecture, elaborate burials, mysterious mythology and codices? Structure from Motion.

What is Structure from Motion?

11001549_801559629936426_4372201199926844354_o

Here I am focused on photographing my unit for SfM.

Structure from Motion (SfM) is a surprisingly simple technique that is easy to learn, quick to do in the field, and potentially available to archaeologists wherever they work, or at least those with access to modern technology. SfM uses still-motion photography to rebuild real-world, dimensional objects. Using a digital camera you take a series of overlapping, sequential photographs of your desired target and run them through a software program, such as Agisoft Photoscan.  The software is able to match up all the different photographs and build a virtual 3D model of the target (for more info on what Structure from Motion is, see our blog post from last spring:  Structure from Motion).

For the ASWT project, we are using SfM to document and record everything from entire sites to small excavation layers.  In other words, a digital camera and a computer take the place of the traditional pencil and sketch map technique that I became familiar with in Belize.  Creating sketch maps is somewhat fallible in terms of reliability due to human error; we can only record and note what we see or notice at the site. Often, having only a single chance to record something before we move on to the next layer. Even more often when we sketch we focus on the big things, the obvious things, not necessarily because we think the rest inconsequential, but because we cannot physically draw every detail. SfM captures all of the visual detail that we can’t see or maybe don’t even think to include at the time because we’re so focused on recording our super cool projectile point or rock alignment.

When it comes down to it, many of the steps and methods are the same (we’re still completing forms and taking notes and we aren’t taking any shortcuts), but what really changes is the end product: our results. Our notes, drawings, photos, and forms are all we have left after an excavation. SfM offers us a permanent, virtual record that preserves and offers accessibility to our excavation data for years to come (and dozens more eyes). Nothing gets skipped over, nothing forgotten.

Our Work So Far

Eagle Cave South Trench Strip numbering system.

Eagle Cave South Trench Strip numbering system. Strip 4 is where I focused my work for the first session in Eagle Cave.

As I mentioned in my introductory blog post, I am interested in archaeological applications of GIS. I also mentioned that I was intrigued by the SfM technique that I myself first learned about from this blog [Eagle Nest Canyon at the Texas Archeological Society Annual Meeting]. Now I come to you one month in, with a bit more knowledge on the project and the technique to present another perspective.

I spent the January session re-exposing a profile face, PS005, that was initially exposed in 2014. This profile sits in what we now call Strip 4, almost smack dab in the center, top section of the South Trench wall of Eagle Cave.

Digital annotation of PS005 orthophoto from 2014 before profile sampling.

Digital annotation of PS005 orthophoto from 2014 before profile sampling.

PS005 with micromorph samples superimposed and georeferenced onto the profile.

PS005 with micromorph samples superimposed and georeferenced onto the profile.

At first it was a mess. After removing the backfill and geo-cloth, we discovered that the profile face had suffered damage from continued erosion and rodent burrowing since it was originally exposed. In 2014, the investigators assigned strat numbers based on their original profile exposure –i.e. each visible stratum received a unique number.  However, they then excavated a small sampling column and did their best to follow the layer seen in profile across the unit. The presence of numerous rodent burrows, especially through the ashy layers, made strat definition challenging.

I should add one more factor, at the end of the 2014 excavations the PS005 profile was sampled by the geoarchaeologists who removed micromorphology samples.  Although done carefully, the wall was no longer pristine.

PS005 profile we exposed in 2015.

PS005 profile we exposed in 2015.

This helps explain why when we re-exposed the PS005 profile we could not easily match what we were seeing in the field to the original profile illustration. So, we decided to excavate a sampling column through a portion of the jumbled profile, using the 2014 strat numbers for our layer designations . This was done with two goals in mind:

1) Cut back eroded face (profile) and re-expose the stratigraphy.

2) Collect high-resolution samples of the matrix and artifacts within the profile.

Excavating a sampling column involves collecting the matrix of each layer (along with things like Spot Samples, Geo-matrix Samples, and samples for radiocarbon dating) that can be further analyzed in a lab.  We are not only collecting samples of each strat, but using the TDS shots of each sample and the strat location, we will add them all to the SfM model. So whoever processes and analyzes the samples can have a virtually exact geospatial reference of its origin. This will help us build an assemblage of associated artifacts, radiocarbon dates, and deposition event, aiding in our understanding of the shelter and the canyon: how it was used, when it was used, what they were doing there.

Rather than draw a standard paper and pen illustration of each layer as we excavated, we instead used SfM to document the top surface of each strat. This not only gives us an idea of what we were looking at, but it allows us to use GIS to calculate volume of matrix removed.

Field annotation of the strats in PS0010: 2015, previously PS005: 2014, that Charles and I completed.

Field annotation of the strats in PS0010: 2015, previously PS005: 2014, that Charles and I completed.

Once I finished with the sampling column, attempting to follow the strats that were assigned the previous year, the profile face that was exposed was extraordinarily rich.  In other words, by cutting back the wall we found better preserved and more complex stratigraphy. The newly exposed profile exposure is called PS010.

Previously, only about 10-12 strats were identified in this area.  We have now defined 22 individual strata from the “same” exposure. I re-photographed the profile giving us three sets of 3D data: TDS shots, 3D models of all the excavation layers, and now the model of newly exposed PS010. We now have a new high resolution 3D model to overlay all of the excavation layers and samples onto – all of which can be manipulated to aid in analysis.

Where it All Comes Together

Our field lab is where all the sets of photographs are processed. Using Photoscan we align and georeference all the images for each individual layer. The photographs, GCPs, TDS, and notes are all combined to digitally rebuild the excavation. A 3-dimensional, manipulable dataset that works hand-in-hand with all of the physical data—matrix, artifacts, etc.—and the recorded data i.e. notes, photos, etc. In order to have these georeferenced for GIS or used in photogrammetry, no less than six GCPs, ground control points, are included in each excavation exposure. Ground control points are geospatial reference points that you place on your object or in your unit, shoot in with a TDS or GPS, so that photographs and models can not only be more accurately aligned with each other, but linked to a geographic grid. This becomes incredibly handy when you are working in say, a canyon with multiple sites carrying on extensive excavations that you would like to map and relate to one another. Then, not only can you reference all of your units and sites among the canyon, but you can reference and cross-analyze your work with other sites across the region or the world. Once we have our models we can then export all or parts of the model into many different formats; GeoTIFF, TIFF, JPEG, KMZ, etc. Our models are ready to imported into GIS software where we can further manipulate and analyze them.

This shows the samples that were taken in the PS005 sampling column. They are superimposed onto the 2015: PS010 orthophoto.

This shows the samples that were taken in the PS005 sampling column. They are superimposed onto the 2015: PS010 orthophoto.

Orthophoto of complete PS010 profile face.

Orthophoto of complete PS010 profile face. An orthophoto is created once the SfM modeling is completed, GCPs added into the model, and then exported into ArcGIS for more analysis.

Our Answer

A goal of the ASWT project is to not only excavate and collect, but to gather the best data we can – or best representation of that data –backing it all up with SfM and GIS.  Structure from Motion gives us the opportunity to not only georeference our units, finds, and strata, but we can literally rebuild them, at least digitally speaking. No longer are we relying upon the traditional mapping, measuring, and sketching techniques of years past that result in rather dimensionless visualizations of excavations.

SfM also easily provides a new solution to an old problem: excavation vs. preservation. The basis of archaeology is essentially destroying material history in the name of research and discovery, so that we can preserve and record it as best we can. Granted we have gotten much, much better at recording and excavating than back in the early days of the field, there is still room for improvement and innovation. In 2014, Bryan Heisinger (2014 ASWT Intern; 2015 ASWT Staff Archaeologist) presented at the Texas Archeological Society annual meeting, on the uses of SfM and GIS for not only modeling, but extrapolating volumes of material removed and creating digital elevation models (DEMs). These can be used to study stratigraphy and depositional events of floods, people, and even animals– as Emily and Larsen can attest to. Our documentation of profiles, like PS005 and PS010 helps us build a database of all the excavations and the shelters to aid in the analysis of what is to some a rather abstract concept of time. Our work becomes more dimensional, more visible. You aren’t just looking at the profile of a wall or structure or shelter. You can virtually walk around that wall, walk into that structure, and around that shelter, without ever being there. The outreach potential is exponential.

The ASWT project personnel and many of our colleagues believe that SfM is that next step in improving archaeological documentation. Incorporating SfM and GIS technology we can model excavations with millimeter level precision recording finer detail in stratigraphy and location than ever before. Physical 3-D models that can be pieced together or pulled a part. High resolution, detailed, and accurate data that can be manipulated, viewed, and analyzed virtually any way we desire. Even better we can share our results in a brand new ways: 3D printing, virtual tours, etc., we could and can literally print pieces of art, artifacts, even a scale model of the canyon if we wanted to! This project, this technique isn’t just for the archaeologists and researchers understand the shelters better, our goal is to be able to help everyone understand the shelters better because the shelters are a part of all our histories.

To elaborate on what Charles has said numerous times and will likely say many more, “50 years ago they were using completely different techniques..50 years from now they’ll be using completely different techniques…but right now we have the technology and the opportunity to set those standards for the next 50 years. We are doing something amazing here with SfM, and sure, we’re not the only people using this method, but there could be a dang lot more of us using it.”

If you haven’t already, you should click on over to our older posts on the subject, and I highly encourage you to visit the Mark Willis Blog http://palentier.blogspot.com/, where you can see some of the other extraordinary uses of SfM 3-D modeling.

Between a Rock and a Heart Place

By Bryan Heisinger

Last year during the 2014 Eagle Nest Canyon Expedition, the crew surveyed the land around the Shumla campus for a fresh spot to establish an experimental earth oven facility. As described by Jake Sullivan and Brooke Bonorden (see Searching for the Trifecta), earth ovens are a cooking technology used by the people of the Lower Pecos (and across the world) to bake plants and animals that would otherwise be inedible to humans.

The remains of earth ovens are found at thousands of archaeological sites across the Lower Pecos Canyonlands region, including Eagle Nest Canyon.  At Eagle Cave, the massive heep of earth oven cooking debris–mainly fire-cracked rock (FCR)–has accumulated from the repeated use of the site for constructing earth ovens, probably over thousands of years. Though highly recognizable and important to our understanding of the human occupation and use of Eagle Cave, the many hundreds of tons of burned rock that fill this and other rockshelters within Eagle Nest Canyon has been poorly studied and documented by archaeologists who have worked here over the past 80 years.

In reaction to this negligence towards FCR and earth oven research, the ASWT project has made it a priority to study and quantify the amount of earth oven cooking that occurred in the uplands and rockshelters in and around Eagle Nest Canyon.  As we documented in 2011-2012, similar evidence can be found along Dead Man’s Creek, a tributary of the Devils River, and across the region and beyond. When studying earth ovens, one of the best ways to become acquainted with the methods of earth oven technology  is to use experimental archaeology and actually build one!

The ASWT Experimental Earth Oven:

Back in 2014 when we were surveying the Shumla campus for a suitable spot to build earth ovens, we had three criteria to keep in mind while looking for the perfect location: 1. Soil, 2. Fuel,  and 3. Food. Not to mention, we took care to avoid establishing an oven at a known archaeological site! Soil, fuel, and food are the desirable location traits needed for a successful earth oven, because you need soil to dig an oven pit, you need wood to build a fire, and you need food (in our case sotol or lechuguilla) to cook. The crew eventually found a favorable spot near campus and cleared the surrounding brush for the ASWT Experimental Earth Oven locality.  Unfortunately, due to burn bans, lack of time, and conflicting personal schedules, the 2014 ENC expedition was never able to build an experimental earth oven

Fast forward to this year: On January 11th, three days after the new ASWT interns arrived at the Shumla campus, the weather conditions were highly favorable to finally build our long awaited experimental earth ovenAfter gathering enough firewood (fuel), lechuguilla and sotol (food), and close to 100 kilograms of limestone clasts from the immediate surroundings, the crew was ready to begin constructing the earth oven.

We began by digging a pit close to a meter and a half in diameter, and a half a meter in depth. The firewood (hand-gathered deadwood) was then stacked in a conical pyre (similar to a tepee), and the limestone rocks were strategically placed within the cone of firewood.

The crew agreed that it was best to light the fire the traditional Lower Pecos way, so Park Archaeologist Jack Johnson of Amistad National Recreation Area (US National Park Service) used the bloom stalk of a sotol plant to start a friction fire. In under 2 minutes, Jack had the fire blazing under the stars (for a time-lapse of the earth oven fire, watch this video by Jack Johnson: https://www.facebook.com/video.php?v=10152425529847134&pnref=story).

IMG_1173

The blazing conical pyre of firewood and limestone rock in shorty after it was fired.

 

After the fire burned down to embers and the rocks were glowing red hot in the bottom of the pit, the crew and several student volunteers from Texas State University began lining the the pit with prickly pear pads – the pads serve as a lower layer of packing material that helps to retain the moist heat needed to bake the food at a low temperature (ca. 100 C) for an extended period of time (typically 36 -48 hours.)

IMG_1262

Placing the first layer of packing material (prickly pear pads) ontop of the hot limestone rock.

 

Once the prickly pear was placed, it was time to throw in the food we collected. Lechuguilla and sotol hearts (3 each) were placed in the center of the pit on top of the prickly pear and covered again with more packing material.

IMG_1266

Laying the food (Sotol and lechuguilla) on top of the packing material.

 

After the remaining packing material was thrown over the food, we began to cover and cap the pit with dirt; this cap of soil insulates and holds in the steamy heat released from the rocks and suffocates the fire allowing no combustion. Now it was time to wait for our plants to bake and hope our hard labor would deliver some tasty results!

IMG_1274

Capping the earth oven with soil.

 

 

IMG_1281

Charles packing down the cap of soil to ensure no heat escapes.

 

Dinner is Served:

On the evening of January 13th, two days after we capped and sealed our earth oven, the crew returned to taste the baked desert succulents that were slow cooked over the last 48 hours. While digging the bulbs out of the pit, we noticed how the soil was still warm from the heated rocks below. The baked lechuguilla and sotol had a turned a caramelized color and had an aroma that smelled similar to a smokey artichoke.

IMG_2799

The baked bulbs of sotol and lechuguilla.

 

The palatability  of these baked plants sent mixed expressions across the faces of our crew, some of who enjoyed the flavor and some who didn’t.

2015-01-13

Tasting our baked food for the first time. The faces say it all.

 

Learning from Earth Ovens:

A great variety of scientific information potentially can be obtained from the experimental construction of earth ovens.  One aspect of earth oven use ASWT is particularly interested in is understanding the rate at which limestone rock breaks down through repeated use in earth ovens. The layer of heated limestone rocks forming the bed of an earth oven serves as a thermal storage or heating element that slowly cooks the food. During the firing process, the limestone rocks begin to break apart from the intense heat that they are exposed to (over 500 C).  Through reuse, thermal cycling–from cold to hot to cold again– causes the rocks to continue to fracture into ever smaller pieces.  Solid rocks with few flaws typically last longer than naturally fractured rocks and those with thin spots. Once the rocks becomes too small to retain heat, they are no longer effective thermal storage devices and they are discarded and tossed into what will become a debris ring around the oven pit, eventually qualifying as a burned rock midden. If we can track and measure a known mass of limestone rock (e.g., 100 kilograms/220 pounds) as it continuously breaks down into smaller rocks from heat and re-used in new earth ovens, we could then to apply this experimental rock-size attribute data to the fire-cracked rock (FCR) that we find in such profusion in the archaeological ground. In other words, this experimental use of earth ovens can potentially allow us to more accurately measure the amount of earth oven cooking that took place in Eagle Cave and other rockshelters and open sites in the region.

Eagle Cave’s Feature No. 8:

Last week, Emily and Larsen uncovered what we think is an intact earth oven heating element in their excavation unit. To a trained eye, this earth oven feature was characteristically textbook in its makeup. Many of the limestone rocks were inclined at the base of the pit and the soil that surrounded these fire-cracked rocks was heavily organic, ashy, and rich with dime-size charcoal chunks. It even appeared as if there had been a different soil that was used to cap this earth oven once long ago.

Feature8

3D model (plan view) of feature 8 in Eagle Cave. Notice the dense cluster of fire cracked rock and black/grey charcoal rich soil.

 

 

2015_01_22

Plan and profile view of feature 8 in Eagle Cave.

 

With intact, well-preserved finds such as Feature 8, we have the ability to obtain radiocarbon dates that can help us determine when this oven was used.  Furthermore, we can sieve the collected soil from that earth oven feature and, with the help of our collaborating archaeobotanists, identify the charred plant remains that were being processed by the people who lived in Eagle Cave. What we cannot do is accurately estimate how many times this earth oven was re-used. Was Feature 8 a one-time earth oven event? Or was it the last of series of earth ovens that had been built and re-used in this very spot using the same rocks? These are some of the questions that ASWT would like to address in our ongoing research. Through these initial tests with EEO No.1 and other experimental earth ovens to follow, we believe that the data to answer these questions could come to light.

ASWT Experimental Earth Oven (EEO) No. 1

After enjoying the success of our first experimental earth oven, we returned  a week later to dig out all the rocks from EEO No. 1.  We used 11 rocks larger than 15 cm in maximum dimension in the oven (99 kg or ~220 lbs of total), and we were able to recover all the rock that was used.  Most of the rocks survived the fire, but as you can see from the photograph below, some of the rock broke into smaller fragments.

OLYMPUS DIGITAL CAMERA

The rock size sorted fire cracked limestone, post earth oven firing.

Once all the rocks were pulled out of the oven, we divided the rocks into four size categories: <7.5 cm in maximum dimension, between 7.5-11 cm, 11-15 cm, and >15 cm in maximum dimension.  We used the same familiar size categories we use in the recording procedure we call “Rock Sort” which allows us to quantify the rocks from each excavation unit-layer.  The smallest two size classes (<7.5cm and 7.5-11cm) contain rocks that are too small to be effectively used again as rocks for the heating element.  After counting and weighing all the rocks in each size class, almost all of our rock (93 out of 99 kg) survived to be used again.

OLYMPUS DIGITAL CAMERA

Weighing the fire cracked limestone rock.

 

Likely during our next session, all the useable limestone rock from ASWT EEO No. 1 will be re-used in another experimental earth oven event.  After the second firing (ASWT EEO N0. 2.) we will once again recover all the rocks, sort the rocks into different size categories, and weight all of them.  We will continue to re-use the same rocks until the rocks all become too small (<3.5 inches) to effectively retain heat anymore. The more times we “burn” the rocks, the more data we will collect to further our goal.  We anticipate great data and results to come!

 

ENC Act 2: Return to Eagle Cave

By Charles Koenig

Yesterday we wrapped up our first week of field work for the 2015 season, and things are off to a great start (even if the weather is a little chilly).  Last year we worked at four sites within ENC: Skiles Shelter, Horse Trail Shelter, Kelley Cave, and Eagle Cave as discussed in previous posts.  To recap, we completed our planned investigations at Skiles and Kelley, we carried out initial testing at Horse Trail, and we got started at Eagle.   Although we learned a great deal by working at four different sites, this year we will focus on one site: Eagle Cave.

The 2015 ASWT crew, assisted by student volunteers from Texas State, begin exposing intact stratigraphy in Eagle Cave.

The 2015 ASWT crew, assisted by student volunteers from Texas State, begin exposing intact stratigraphy in Eagle Cave.

As described in the blog post from last spring (see Eagle Cave: Where Context is Crucial), previous archaeological work in Eagle Cave in the 1930s and 1960s, and subsequent erosion, resulted in the massive trench spanning from the rear wall to the dripline.  Based on the work done by the Texas Archeological Salvage Project during 1963, we know that the deposits the trench bisects are between 10 and 20 feet  deep (3-6 m).  Through the decades the once-vertical trench faces gradually succumbed to the forces of gravity, wind, burrowing critters, and misplaced footsteps, leaving a sloping U-shaped depression.  We planned from the outset of the project to expose, sample, stabilize, and backfill the trench, but we needed to gain experience working in other areas of the site before taking on the daunting task of the main trench.

Plan view of Eagle Cave showing the location of the 5 Profile Sections excavated in 2014.

Plan view of Eagle Cave showing the location of the 5 Profile Sections excavated in 2014.

Last season we opened up 5 small “windows” in different areas of the site.  Profile Section (PS) 1 was on the downstream side of the site were a large badger burrow exposed surprisingly intact deposits just under the surface.  Only a few meters away, PS 2 began in the disturbed deposits along the rear wall which had been dug out long ago by the Witte, the “local boys” of Langtry, and burrowing animals. As we removed the deeply disturbed rear wall deposits and worked our way outward we encountered intact remnants there too.

Profile Sections 1 (left) and 2 (right).  Each profile was generated using Structure from Motion software.

Profile Sections 1 (left) and 2 (right). Each profile was generated using Structure from Motion software.

Profile Sections 3 and 4 were located in the UT North excavation unit in the upstream end of the site (and are the subject of Tina Nielsen’s thesis research project).

Profile Sections 3 (right) and 4 (left) were excavated in the UT North Unit.  Excavations reached bedrock over 3 meters below surface.

Profile Sections 3 (right) and 4 (left) were excavated in the UT North Unit. Excavations reached bedrock over 3 meters below surface.

The final exposure was PS 5 – located in the upper part of the south wall of the main trench, where erosion had provided glimpses of intact layering.

PS 5 was exposed on the south wall of the main trench at the end of the season.

PS 5 was exposed on the south wall of the main trench at the end of the season.

Each of these exposures (PS 1 – 5) gave us the opportunity to test, modify, and improve our excavation and sampling methods, as well as gain experience documenting the complex and fragile stratigraphy of the dry rockshelter deposits.  Yet, each exposure provided only a rather narrow (~3-4 feet) view of the deposits, and it was difficult to link stratigraphic layers between profiles.  Our 2014 experience drove home the realization that in order to gain a better understanding of the deposits, we would need more substantial stratigraphic exposures – and there is no better place to do so than in the main trench.

 

The focus of the 2015 field season is exposing, recording, sampling, and stabilizing the south wall of the main trench.  We want to take advantage of the slumping trench wall and expose as much intact stratigraphy as we can.  In other words, we want to frame the microstratigraphic layering seen in small windows within the context of the larger structural patterning visible across the site. We are continuing to step our profiles vertically and horizontally to maintain stability (and provide access), and we are following the same “Low Impact, High Resolution” sampling strategy (See Low Impact High Resolution).

This past week we re-exposed PS 5, which we had draped with landscape cloth and gently covered with fill at the end of the 2014 season.  And we began opening up fresh exposures at two additional locations along the trench (see the time lapse above).  As the season progresses we will step down the exposures deeper into the trench, but for now we are focused on the upper deposits.  By the end of the 2015 field season we expect that we will have documented and sampled rather spectacular stratigraphic exposures along the main trench, and we look forward to sharing what we find!

Back in the Canyon: The 2015 Eagle Nest Canyon Expedition

OLYMPUS DIGITAL CAMERA

We’re back!  Today marks the first work day of the 2015 Eagle Nest Canyon Expedition.  We are very excited to be back, and are looking forward to another fantastic field season.  Unfortunately, Steve will not be spending as much time in the Canyon this spring as he would like, but he has left me (Charles) to run the project in his place.  I am joined once again by Bryan Heisinger, one of the interns from last spring.  Bryan returns to the ASWT project after spending another summer in the Sierra National Forest, and will be serving as Staff Archaeologist for the duration of the spring.  Along with Bryan and myself, we are fortunate to be joined by three outstanding interns: Matt Larsen, Victoria Pagano, and Emily McCuistion.

Emily McCuistion

OLYMPUS DIGITAL CAMERA

I was born in Austin, TX and there I remained (for the most part) until graduating with a BA in Anthropology from the University of Texas. Since then I have followed archeology work to some remarkable places including Death Valley National Park, where I fell in love with the desert, and Denali, Alaska. Most of my archeology experience has been with the National Park Service and US Forest Service doing survey, site recording and condition assessments, and aiding in management decisions pertaining to cultural sites. I also worked in NSW, Australia consulting for development projects, briefly worked on
a nautical excavation of a Civil War gunboat off the Texas coast, and detailed on the BP oil spill clean-up at Gulf Islands National Seashore.

I am now pleasantly surprised at my good fortune as to be doing archeology where I have longed to be, in southwest Texas, and with a team that is so innovatively balancing preservation and data retrieval. I am excited to learn from and contribute to our knowledge of history and landscape of the striking and enigmatic Lower Pecos Canyonlands.

 Victoria Pagano

pagano

I graduated from UTSA in 2014 with my B.A. in Anthropology. My sole archaeological experience was a month long field school in central western Belize as part of the MVAP/MVPP project headed by Dr. Jason Yaeger and Dr. Kat Brown, where I worked at Buenavista del Cayo. In 2011, I worked as an Interpretation Intern at Petrified Forest National Park; I guided and informed park guests on all aspects of the park: archaeological, historical, geological, and paleontological. My experience at the park has placed conservation and stewardship as a priority in my work and goals, which I am glad to find are important aspects to this project. I spent Fall 2014 in UTSA’s GIS certificate program learning some GIS and remote sensing. I focused my work in the program on wildfire effects on vegetation and wildfire patterns in Arizona. As part of this ENC team I look forward most to working in project that is aimed towards bringing archaeological records into the future with new techniques and standards. I am excited to learn more about the Structure from Motion software and explore the field of geoarchaeology.

Matt Larsen

larsen bio

My name is Matt Larsen, though I usually go by Larsen because there are always at least 2 other Matts in any large enough group. I graduated with a degree in German from UT-Austin in 2008 and put that to good use by working at Pete’s Piano Bar in Austin for 6 years or so. In 2012 I decided to follow a life-long dream and become an archaeologist. I attended Texas State and received my second B.A. in Anthropology in December of 2014.

While at Texas State I interned with the curation lab at the THC’s Historic Sites Division’s repository in Austin. While there I spent my time processing the archaeological materials from Fort Griffin State Historic Site. I also worked as an undergraduate intern for the final quarter of the 2014 ENC field expedition. I learned quite a lot in that 6 weeks and made some good friends. I enjoyed backfilling excavation units so much I decided to quit my job and join the 2015 ENC field expedition for the full duration.

I am excited to get back out there and get really, really dirty again. The LPC is a very special place due to the magnificent preservation conditions and the fantastic rock art. I enjoy working with ASWT for several reasons. I am excited about continuing to work with pioneering digital photogrammetric techniques. I enjoy working with the celebrity guest archaeologists Dr. Black brings out on a regular basis. Finally, I am excited to see what we uncover! Besides the archaeology I am looking forward to working with the great folks from SHUMLA and the Skiles family. I am also curious to see what kind of critters we rustle up this year. If you know Dr. Black, then you know it ain’t archaeology without a snake story!

Eagle Nest Canyon at the Texas Archeological Society Annual Meeting

By Charles Koenig

This past weekend the Texas Archeological Society held its 85th annual meeting in San Marcos, Texas, and the Eagle Nest Canyon project was well represented.  Steve Black and I began the symposium with a 40-minute introduction highlighted by a series of animations created from the 3D models we have generated from our work thus far.  The six animations, such as that of Eagle Cave shown below, were narrated and aided by additional images.

Eleven additional speakers and ENC research team members rounded out the ENC symposium (abstracts below).  We also created a poster (Skiles et al. Eagle Cave_TAS2014 Poster) to highlight the excavation methodology we are using at Eagle Cave.  All of the presenters gave excellent presentations, and we are looking forward to learning from the ongoing analyses.  Stay tuned for new blog posts, and we will have another symposium at the Society for American Archaeology Meeting in San Francisco next April!

2014 Expedition to Eagle Nest Canyon

ENC01

Eagle Nest Canyon from the air. UAV Imagery courtesy Mark Willis.

Stephen L. Black, Charles W. Koenig, Mark D. Willis, and Charles D. Frederick

This presentation introduces the symposium and the 2014 Expedition by the Ancient Southwest Texas Project of Texas State University, as well as sites within Eagle Nest Canyon with an animated overview of the canyon. The ENC Expedition has three overarching research goals: 1) understand the human and natural history of the canyon; 2) share what we learn; and 3), conserve the archaeological record for future generations. From January through June a small core research team worked side-by-side with landowners Jack and Wilmuth Skiles and dedicated volunteers, collaborators, and partners to further these goals.  Our strategy is to apply state-of-the-art, multi-disciplinary research methods to documenting and sampling the complexly and deeply stratified deposits at two dry rockshelters with extremely well preserved organic remains and two shelters with shallow overhangs.  Our guiding motto “Low Impact, High Resolution” characterizes our approach.

Sites, Features, and Artifacts of the Canyon Edge, Eagle Nest Canyon

Matt describing a small upland burned rock feature on the Canyon Edge.

Matt Basham describing a small upland burned rock feature on the Canyon Edge.

Matt Basham, Texas State University

The canyon edge is a common geographic zone throughout the Lower Pecos Canyonlands of southwest Texas.  The edge around Eagle Nest Canyon, in particular, was used by prehistoric people for thousands of years.  Archaeological surveys of the area, most recently by the Ancient Southwest Texas Project of Texas State University, have documented a variety of sites, features, and artifacts that have helped reveal the length and scope of human activity in this unique geographic setting.  This paper will present an overview of the canyon edge around Eagle Nest Canyon.  A brief description will be given of each site in this zone.  In addition, the radiocarbon dates of several burned rock features and diagnostic projectile points will be discussed that are relevant to determining the length and scope of human activity on the edge of Eagle Nest Canyon.

In Search of the Basketmakers: The Story of the Early Witte Museum Expeditions to Eagle Nest Canyon

Stephanie Mueller excavating PS05 in Eagle Cave.

Stephanie Mueller excavating PS05 in Eagle Cave.

Stephanie Mueller, Witte Museum

In a race to be among one of the first institutions to acquire artifacts from the earliest known culture in Texas at the time, the Witte Memorial Museum sent out fifteen known expeditions to archeological sites throughout western Texas within the first two decades of its institutional history.  At least five of those expeditions ended up in Eagle Nest Canyon.  The first of those was a scouting expedition in 1922 to Eagle Cave (41V167).  Four other expeditions followed in the 1930s where the museum conducted excavations in Eagle Cave, Jacal Shelter (41VV674), and other sites in the vicinity of Langtry, Texas.  This paper provides an overview of the known Witte expeditions to Eagle Nest Canyon and reports recent findings of one of the museum’s campsites utilized during the later expeditions.

A Microstratigraphic Approach to Evaluating Site Formation Processes at Eagle Cave

Tina running the TDS in Eagle Cave.

Tina running the TDS in Eagle Cave.

Christina Nielsen, Texas State University

Eagle Cave (41VV167) is a large dry rockshelter with deep stratified deposits spanning the Early Archaic through the Late Prehistoric periods. My thesis research focuses on the deposits in the northern sector of the shelter sampled during the 1963 excavations by UT-Austin and again a half century later by Texas State University in 2014.  My goal is to use multiple lines of evidence to evaluate the natural and cultural formation processes that resulted in the complexly stratified, culturally rich deposits present in Eagle Cave.  By using data derived from stratigraphic documentation, geoarchaeological sampling, artifact analysis, macrobotanical and faunal identification, constituent size distribution, and radiocarbon dating, I hope to develop a viable protocol for understanding the site formation processes evident at Eagle Cave and many other Lower Pecos rockshelters.  This presentation summarizes the microstratigraphic approach taken during the 2014 field investigations and highlights methodological and analytic challenges.

We Dig GIS! Studying Lower Pecos Stratigraphy with ArcGIS

Bryan standing in front of PS3 in Eagle Cave.

Bryan standing in front of PS3 in Eagle Cave.

 Bryan Heisinger, U.S. Forest Service (2014 ASWT Intern)

Throughout the ENC 2014 project we used Structure from Motion to document and photograph each excavation unit-layer.  Using the photogrammetry software, we are able to create digital surface terrain representations and digital elevation models (DEMs) of excavation unit-layers with sub-millimeter accuracy.  In turn, each DEM can then be manipulated with ArcGIS in such a way to not only show and measure the precise opening and closing dimensions of an excavated unit, but also calculate total volume of material excavated—no matter the shape or size.  Additionally, these digitally recreated excavation layers can be overlaid onto a unit’s stratigraphic profile in ArcGIS to compare the pre-defined strata of a profile to what was actually excavated and seen in profile view.  Together by using ArcGIS and Structure from Motion photogrammetry software, the ASWT Project has begun extracting excavation unit data in a new and potentially more efficient way.

Preliminary Analysis of Archaeobotanical Materials from Kelley Cave

Kevin (far right) points out scars that suggest the deep mortar hole that goes all the way through this small boulder was quite intentional.  He has seen similar "artifacts" in Tamaulipas.  Incidentally, we think J. Charles Kelley described this very rock in May 1932 when he and E. B. Sayles dug small tests in Eagle Cave.

The Macrobotanical team examining a large grinding slab in Eagle Cave.

Kevin Hanselka, Leslie L. Bush, J. Philip Dering, and Stephen L. Black

Abundant well-preserved plant remains recovered from sheltered sites in Eagle Nest Canyon illuminate ecological interrelations between the prehistoric site occupants and the surrounding natural landscape. These materials have implications regarding: preferences and selection of local plants for food and fuelwood; behavioral patterns of food plant harvesting and processing; modification of plant parts into material culture such as tools, cordage, and textiles; seasonality of site use; and the nature of past environments surrounding the shelters at time of site occupation. In this paper we present the preliminary results of ongoing archaeobotanical analysis of plant materials recovered from Kelley Cave (41VV164). In particular we focus on evidence from Feature 4, a large pit thought to represent an earth oven facility with a complex history of use and abandonment.

Floods, Muds, and Plant Baking: ASWT Excavations at Skiles Shelter

41VV0167_CREW_2685

Charles discussing excavations in Eagle Cave with Matt Larsen and Lindsay Vermillion.

 Charles W. Koenig, Texas State University

Of the Eagle Nest Canyon sites, Skiles Shelter is located closest to the Rio Grande and is the most at-risk for damage from flooding.  Dan Rodriguez tested Skiles during the 2013 Texas State field school. The Ancient  Southwest Texas Project greatly expanded on this initial work in 2014.  Excavations this past spring at Skiles Shelter focused on three main research objectives: 1) understanding the site’s depositional history; 2) quantifying how much earth oven baking occurred there; and 3) relating the prehistoric record at Skiles to the other sites within Eagle Nest Canyon.  Excavations were conducted using similar methodologies employed by ASWT at other Lower Pecos BRM sites, with a focus on collecting samples for radiocarbon dating, geoarchaeology, archaeobotany, and zooarchaelogy.  This presentation will highlight preliminary results of the excavations and ongoing analysis.

 

Morphological Variation of Bedrock Features in Eagle Nest Canyon

Amanda recording the bedrock features at Skiles Shelter.

Amanda recording the bedrock features at Skiles Shelter.

Amanda M. Castañeda, Texas State University

Bedrock features are a common archaeological occurrence in the Lower Pecos Canyonlands. These occur in a wide range of forms, from polished “slicks”, cupules, and small grinding facets to large, deep, well-developed mortar holes. Even though relatively common, bedrock features, and ground stone in general, have received very little directed research in the region. This paper focuses on *** bedrock features from five sites within Eagle Nest Canyon, and highlights ongoing research examining bedrock feature morphology. On-site morphological and macroscopic use wear attributes were recorded for each individual work station, and Structure from Motion photogrammetry was employed to further assess this feature type. Additionally, experimental residue samples were collected from several features in Skiles Shelter. This project will contribute to creating a typology of bedrock features for the region and a base line data set for future studies to expand upon.

Ongoing Geoarchaeological Investigations in Eagle Nest Canyon

Charles Frederick and Ken Lawrence removing a micromorphology sample from Skiles Shelter.

Charles Frederick and Ken Lawrence removing a micromorphology sample from Skiles Shelter.

Ken Lawrence, Charles D. Frederick, Jacob I. Sullivan, and Christina Nielsen

This presentation summarizes the 2014 geoarchaeological investigations conducted at Kelley Cave (41VV164), Skiles Shelter (41VV165), and Eagle Cave (41VV167) and highlights elements of the ongoing analyses. Research begun in 2013 at Kelley Cave and Skiles Shelter was expanded and new work was begun in Eagle Cave. The geoarchaeological investigations have encountered new problems, opportunities, and several surprises. The data obtained from each site includes micromorphological samples, high-resolution cube samples, and bulk matrix samples. This presentation discusses the preliminary results of these investigations, their interpretations, and how they correlate to the cultural deposits from the excavations.

The ENC Micromorphing Power Rangers: Challenges, Trials, and Tribulations of Micromorphology in Dry Shelter Deposits

Jake preparing a micromorphology sample from Skiles Shelter for extraction from the wall.

Jake preparing a micromorphology sample from Skiles Shelter for extraction from the wall.

 Jacob I. Sullivan, Charles D. Frederick, and Ken Lawrence

Documenting stratigraphic exposures can be exceptionally difficult within the dry rockshelter deposits from sites within Eagle Nest Canyon—especially when dealing with the micro-stratigraphy often visible.  Fine dust, carried by wind or cascading down a profile face, threatens to obscure these sometimes delicate and subtle lamina we seek to record.  In order to gain a clearer understanding of the site use and depositional history, we have undertaken an ambitious micromorphology collection strategy for all the sites within ENC.  Micromorphology blocks are carefully removed from exposed profiles, and imbedded within a polyester resin which allows for detailed analysis back in the lab. These  block sampling columns provide high resolution vignettes into the natural and anthropogenic depositional processes at work within each of the rockshelters. This paper is an overview of the methodology and analysis of micromorphology samples taken from Profile Section 5 in Eagle Cave.

Flooding Past and Present: Extreme Geomorphic in the Lower Pecos Canyonlands

Noon, view upstream from above Eagle Cave.

Eagle Nest Canyon flooding during the June 20th flood.

Charles D. Frederick, Mark Willis, Ken Lawrence, Jacob I. Sullivan, Rudy Herrmann, Charles Koenig and Steve Black

Although presently a desert environment, extreme flood events are part of life in the Lower Pecos Canyonlands. This paper examines two such flood events, one preserved in the deposits of Skiles Shelter and Kelly Cave, and another that occurred on June 20th 2014. These events provide examples of catastrophic floods that punctuate the sedimentary records in the shelters and contrast with the more incrementally formed deposits that occur in association with human activity in these settings.  The presentation also examines the issue of which process is more formative in the local landscape: rare extreme magnitude flood events or low magnitude but higher frequency floods.

Preliminary Results from Zooarchaeological Analysis of Eagle Nest Canyon Sites

Dr. Chris Jergens studying faunal remains under a microscope.

Dr. Chris Jurgens studying faunal remains under a microscope.

Christopher J. Jurgens

Distance and a decade of life separate the subjects of doctoral zooarchaeological research and current Eagle Nest Canyon research efforts.  The author returns to Lower Pecos research as an extension to his earlier doctoral research.  Zooarchaeology and bone technology was the focus of the earlier research at Arenosa Shelter (41VV99), the deeply stratified site located in the Pecos River canyon 25 km (15 miles) southeast of Eagle Nest Canyon. Analysis results from Eagle Nest Canyon sites are comparable with those from the upper strata at Arenosa Shelter. Preliminary analyses of faunal materials from the Eagle Nest Canyon sites reveal patterns that compare favorably with those at Arenosa Shelter.  The patterns are similar for skinning, butchering, and bone fracturing; bone tool and ornament manufacture; and subsequent use wear.  Formal and informally manufactured tools are present in both locales.  Tool forms are very similar. Informally manufactured tools are present at both locales.