Archaeology Showcase

Brendan Nash, The Gault Archaeological Project

During the summer of 2013 I participated in an internship with the Gault project. It turned out to be the best experience of my collegiate career. I gained first-hand experience in excavation, lithic analysis, and it greatly increased my understanding of Paleo-Indian culture. I had such a good experience during my internship that I plan to stay involved with the Gault project throughout my Texas State career.

The Gault site is one of the most impressive archaeological sites in North America. The site is more than 800 meters long and 200 meters wide and contains ample archaeological evidence spanning the entirety of known human occupation in Texas. The site is also one of the most important sites in North America, due to the historical implication surrounding its “Older Than Clovis” (OTC) Component.

The laboratory dedicated to the study of the Gault site is located at Texas State University. The team at the Gault lab is carrying out a thorough investigation of the OTC component, and is putting together a report of the findings. The report will include the results from cutting edge microscopic use-wear analysis carried out on artifacts from the OTC assemblage. The team at the lab will also employ other analytical techniques in order to gain data about the relationship between the OTC components and better studied Clovis components. These techniques include replication experiments and direct comparisons of diagnostic artifacts.  The team at the lab is also using cutting edge x-ray fluorescence technology to identify specific chemical signatures of chert (another word for flint) that originated from different locations. The goal of this work is to eventually be able to locate the original source of chert found at archaeological sites. The team will also have to address a number of issues about the context of the OTC component, such as whether or not artifacts have been found “in situe”, which refers to the original location where they were deposited, or if they have been dislocated by geologic or other site-formation processes.

The main focus of the research at the lab is on the “Older Than Clovis” component and its assemblage. The team is investigating this component because of the historical implications of a component of such an old age in Texas. The popular belief is that Paleo-Indian people using Clovis technology were the first people in North America, and that they came from Asia across an ice free land bridge approximately 12,000 years ago. The OTC component at the Gault site has been dated as far back as 15,000 years, which raises new questions. First and foremost, does the OTC component represent Paleo-Indian people who traveled to America earlier than previously thought, or does it represent a separate earlier culture?  And, if it does represent a separate earlier culture, then why do we find evidence of these two separate cultures in the same location?  So the question becomes, do later cultures in this area represent a continuous timeline of the evolution from a single culture or a diffusion of the later Paleo-Indian culture with an earlier Older Than Clovis culture?

The best way for the team to answer this question is to compare the artifact assemblages from relatively well studied Clovis age components with the OTC component. The team has begun by looking at what a typical Clovis assemblage looks like. Clovis technology, as we understand it, revolves largely around the creation of distinct Lancelot projectile points, which are three sided oval shaped spear points with no notching and with the presence of a flute. The method used to make these points is also distinct and involves many difficult techniques, such as the use of fluting, and overshot flaking, which is a flaking technique that creates the desired shape of the point by removing a thin section off of the face of the point and a large mass on the opposite edge of the point from where the flake was struck in a single flake. These techniques produce two distinct by-products unique to Clovis assemblages: Relatively large numbers of overshot flakes and Channel flakes, which are products of fluting. Clovis technology also utilizes long stone blades, which generally range from three to six inches and are struck from a blade core. The blade technology creates a by-product of prismatic cone shaped blade cores, core rejuvenation flakes, and broken blades. The absence of small arrow points is also a signature of Clovis lithic technology. Smaller than spear points, arrow points are not typically seen until Archaic times.

One of the best ways we have to understand Clovis lithic technology is to try to replicate it. For this reason, the archaeological laboratories at Texas State conduct Clovis stone tool replication experiments. This summer I was fortunate enough to participate is a two day replication experiment. The experiment focused on understanding the differences in the debitage produced by unskilled verses experienced nappers. This way, when Archaeologists find debitage in the archaeological record, they can better assess the skill level of the person who created it. This will help archaeologists to better determine the significance of a site from the material remains. About twenty nappers of all ages and skill levels, from professional to amateur, were gathered at the Gault site to try to replicate Clovis stone tool technology. Our debitage was collected and will be analyzed for patterns among similarly skilled nappers.

Carrying out this experiment also greatly adds to the knowledge of individuals who participated in the experiment. From my participation in this experiment I gained an appreciation for how difficult and dangerous it is to create stone tools. I learned that it must take several years to become proficient, and therefore, debitage in the archaeological record must represent nappers of all skill levels. In the archaeological record archaeologists find all sorts of anomalies — artifacts that seem to break the rules of what a particular assemblage is supposed to look like. This may be due to mistakes made by an unskilled napper, experimentation, modification of the tool by a later person, a lack of material forcing conservative use, or any number of difficulties associated with making stone tools. Archaeologists who actively try to replicate Clovis technology will be better adept at identifying certain types of anomalies that they would have produced during their own experimentation. Also, experienced lithic analysts, who are always nappers themselves, can gain a knowledge of their material that is so intimate that they can read emotions, such as frustration, uncertainty, confidence, and excitement of the ancient napper from the artifact itself. Early in my own experimentation I often became frustrated and would try to use extra force and repeated strikes to remove a flake that would not detach from the piece. This caused one part of my piece to become crushed and blocky while other parts remained smooth or would break my piece completely in half, and often times both. A skilled analyst, just by looking at my broken tool, would be able to follow my thought process from the initial frustration to the time when the piece was finally broken.

Another method of collecting data about stone tool assemblages is to send away artifact samples for microscopic use-wear analysis.  When a stone tool, or any tool for that matter, is used to cut or break an object, microscopic pieces of the object become imbedded in the tool. Also, when a tool is used to cut an object, depending on the texture of the object, it polishes or abrades the edge of the tool. Using a powerful microscope, microscopic use-wear analysis allows scientists to look at the edge of a tool with such fine detail that they can identify individual diagnostic plant grains that have been imbedded in the tool from use, or polish/abrasion on the edge of the tool that can be diagnostic of certain materials and activities. Comparing the morphology of an artifact (the three-dimensional shape) with the results from the use-wear analysis allows scientists to better understand what tools were used for what purposes. The team at the Gault lab has sent off samples of approximately 30 tools from the OTC assemblage for this type of testing. Comparing this data with similar data previously collected from known Clovis assemblages will allow the team to identify similarities and differences in the way stone tools were being used. That information will be used to draw conclusions about the differences in life style between the two groups and thus differences in culture.

Then, the team began to identify similarities and differences between the two assemblages by looking at the OTC assemblage. I am currently helping to identifying diagnostic material from the OTC component in order to compare data such as artifact frequency and morphology with similar data from Clovis components. This identification process is just getting underway, because large parts of the OTC assemblage are still being curated and are yet to be studied.

Before any report can be accepted or an excavation can be considered complete by the Texas Historical Commission (THC) or the NSF, all recovered artifacts must be properly curated. The goal of curation is to organize artifacts so that they are easily accessible to researchers and to ensure that none of the provenience information about the artifact is lost. This is done by copying the provenience information of each artifact multiple times and in separate places. The process starts in the field where archaeologists record the provenience information and recover the artifact. That information includes the exact northing and easting of the artifact relative to datum (a set location which all measurements are taken from), as well as the inclination and orientation of the artifact (the exact position, in degrees, in which an artifact was found).  This information is kept with the artifact itself, as well as on a list with all of the other artifacts found within the same excavation unit. Then, in the lab, we hand copy and photo copied the information several time. We may then carefully write an identification number directly onto the artifact itself that will correspond to the written list of artifacts. We will then place it in a small bag that also contains its information.  Finally, the small bag will be placed in a large bag with all of the artifacts from that excavation unit.

Although a large portion of the OTC assemblage is still being curated, the particularly interesting finds are set aside and studied before other parts of the assemblage. In the OTC assemblage the feature that stands out most to us in the lab is the presence of small arrow points. This feature has already spurred a lot of debate and questions about the find. The popular theory is that the bow and arrow came into use in North America around two thousand years ago (http://www.texasbeyondhistory.net/graham/arrow.html) and until then, the spear and atlatl was the only stone tipped hunting weapon used in North America. The idea that people could have been using the bow and arrow in North America fifteen thousand years ago challenges the conventional theories about the evolution of stone tool technology in the Americas and about the life and hunting styles used by the earliest people in North America.

Another major issue the team at the Gault lab will have to address is the notion that the artifacts may not be in original context and may have moved from their original location. Archaeologists use the law of super position to determine relative ages of artifacts. The law states that older artifacts should be deeper in the soil than newer artifacts. This law holds true unless some other mechanism moves the artifacts from their original location, such as geologic processes, pedologic process, bioturbation (the disturbance of artifacts by plants and animals), or by human interference. This is a concern with all archaeological sites, especially sites containing deep sediments and multiple components. It is up to each team of scientists who are working on a site to address these issues.

Due to the massive size of this site, and the fact that it contains cultural material spanning the entirety of known human occupation in Texas in a well stratified context, a number of studies at the Gault site and surrounding areas have already been performed to determine if any vertical  displacement of artifacts is possible. One such investigation was carried out under the direction of Dr. Michael Watters with Texas A&M University (TAMU) at the Friedkin site located on the flood plain of Butter Milk creek.  It is about two hundred meters downstream from the Gault site. Watters (2011) explains that, through the comparison of artifacts diagnostic of a particular time periods and dates derived from Optically Stimulated Luminescence (OSL) dating, that “time-diagnostic artifacts recovered from these horizons are in correct stratigraphic order and correlate with corresponding OSL ages”.

OSL dating is a technique that allows Archaeologists to determine the age of a sediment in which artifacts are found. In a well-stratified site, OSL dates can be used to create a chronology of the layered sediment, which provides context to the artifacts within the sediment. The date derived from this technique is actually the date that the sediment was last exposed to light. The underlining principal of this technique is that when minerals such as quartz, feldspar, and calcite are buried, they absorb background radiation at a known rate. When the minerals are re-exposed to light, they emit the trapped energy in the form of photons. Under controlled laboratory conditions scientists can measure the amount of light released by the mineral sample and draw conclusions about how long the minerals have been buried.

A different type of study was carried out by Dawn Alexander in order to determine if there is any possible vertical displacement of artifacts at the Gault site. The technique used was an artifact re-fit investigation. The re-fit investigation was carried out by painstakingly trying to reconstruct broken artifacts that were recovered from the Gault site, then measuring their vertical distance from each other.  The study concluded that: “the maximum vertical distance between re-fits measured 20 cm, although 67 percent of the thirty-three groups measured a maximum vertical separation of 6 cm or less” (Alexander 2008). This data suggests that there is a margin of error when determining the ages of artifacts relative to each other based on their vertical position within the site. This study was not carried out in an area of the site containing an OTC component. The team at the lab is currently performing investigations similar to the ones performed by Waters and Alexander to determine relative ages of the Clovis and OTC components.

Another type of geoarchaeological study being carried out at the Gault lab is the use of an X-ray Fluorescence Analyzer (XRF) to identify the particular chemical signature of chert from different locations. This data will be used to create a database of chert signatures and their associated location of origin for comparison against chert signatures of individual artifacts. This will allow archaeologists to identify possible trade patterns and to get an idea of the nature of trade in prehistoric times. This type of investigation has only recently become possible with the availability of new technology. Machines that used to take up the space of a small room can now be made to fit into a portable analyzer. Although the technology is now practical for field work the price is not.  The lab spent around thirty thousand dollars on their XRF machine.

My experience interning with the Gault project has provided me with practical archaeological experience both in the lab and in the field. I have learned excavation techniques, lithic analyzation skills, as well as theories about Paleo-Indian culture. This Internship has jump started my interest in Paleo-Indian culture and may have guided my career in that direction. The experience I have gained during my internship will not only help me when applying to graduate school, but it also has provided my with a good foundation of archaeological knowledge I will build upon going forward. I will continue to stay involved with the Gault project because there is still so much I can learn and so much that needs to be done.

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