CAR offers the opportunity for students to gain hands-on experience with cultural material. Read about some of the exciting research our interns are conducting.
Summer 2023
Nondestructive Archaeology
Krystal Vinson wrote a blog about her experience and what she learned over the summer while taking the 2023 Public Archaeology course offered by UTSA and taught by Dr. Jonathan Paige.
Fall 2022
Climate Control and Monitoring for Artifact Preservation
By Jules Pavliska
Jules Pavliska is an undergraduate student in the Anthropology Department at the University of Texas at San Antonio (UTSA). He is a Fall 2022 intern at UTSA’s Center of Archaeological Research with the Curation and Collection management staff. Much of this work centers around the cataloging and storage of collections from Baker Cave, as well as the Mission Reach Project adjacent to the San Antonio River. His duties also include the regular monitoring of temperature and relative humidity (RH) within the facility, to ensure proper preservation standards of the material collections stored there.
Climate Control in Regard to Material Preservation
The Texas Historical Commission (THC) has defined some basic guidelines pertaining to temperature and relative humidity (RH) levels, within collections facilities. Temperature is a very important factor, as this directly affects the RH levels and types of pests or molds that can occur in the facility. Different materials have different sensitivities to temperature and RH fluctuations, such as paper or textile materials generally being more susceptible to these fluctuations than metallic materials (THC 2013). Proper climate control standards usually try to find a happy medium for temperature and RH levels that can account for the diversity of materials stored. A very common medium within a collection facility is a temperature somewhere within the range of 68 to 72 degrees Fahrenheit, and RH levels between 45–55 percent (THC 2013). What poses the greatest danger to material preservation is rapid fluctuations in temperature and RH levels, rather than temperatures being offset by a few degrees, without fluctuating rapidly. This means that seasonal changes in temperature, while certainly important to consider, are much less threatening than daily temperature fluctuations between night and day. Because of this, a facility’s medium of temperature and RH levels need to be maintained 24 hours a day throughout the year (THC 2013).
Facility Considerations when Managing Climate Control
Decisions concerning how a collections facility manages climate control can often involve a wide array of factors. Considerations must often include the architecture of the facility itself, what general region or climate the facility is located in, the main function of the facility, as well as economic questions concerning the costs of maintaining climate control within the facility’s budget constraints (Staniforth 2014). Dialogues and research pertaining to which specific temperature and RH level mediums are most effective for material preservation have been sparking debates for many years. It can sometimes be a complex process to sift through all the available research to find a happy medium of temperature and RH levels that can satisfy the preservation of the wide array of materials and considerations within a given facility (Staniforth 2014). A museum, for instance, must often keep different factors in mind compared to a facility that focuses on preservation alone, such as the comfort of visiting patrons. This implies that there should be open communication and collaboration between facility management and conservators, so that all considerations are accounted for (Staniforth 2014). Within the past few decades, many facilities are being asked to consider their carbon footprints regarding the energy required to maintain and monitor climate control. And as newer, sustainable, or “greener”, energy technologies are being developed, there is also indication that facilities can lower the monetary and energy related costs of climate control systems, while simultaneously reducing carbon emissions (Staniforth 2014). There are even some critiques that more complex, mechanical, and expensive heating, ventilation and air conditioning (HVAC) systems can be less reliable in practice. Failure of these systems can cause rapid fluctuations in temperature and RH levels, and thus be extremely detrimental to material preservation (Neuhaus 2012). Thus, there is an indication that more expensive systems
do not always translate to more effective systems. This also stresses the importance of the regular monitoring of temperature and RH levels through data loggers, without relying too much on more complex automated warming systems that can fail or overcompensate, resulting in rapid temperature and RH fluctuations.
Importance of Climate Control Monitoring and Research
It is important that any facility adheres to a set of predefined standards regarding climate control. At UTSA’s Center of Archaeological Research, the regular monitoring of data loggers tracking temperature and RH levels throughout the facility is a vital task. It is the collection facility’s (and intern’s) responsibility to ensure the climate control systems effectively function to preserve the material collections stored there. These materials contain a wealth of knowledge that may be tapped into for years to come, which is precisely why their preservation is of upmost importance.
Sources
Texas Historical Commission (THC)
2013 Basic guidelines for the preservation of historic artifacts. thc.texas.gov. Texas Historical Commission.
Neuhaus, Edger
2012 A Critical Look at the Use of HVAC Systems in Museums. Climate for Collections | Standards and Uncertainties | Munich 2012.
Staniforth, Sarah
2014 Safeguarding of collections: Future trends - JSTOR. JSTOR.org. Taylor & Francis, Ltd. on behalf of the International Institute for Conservation of Historic and Artistic Works, July.
Spring 2022
Working with 3D Models
By Jessica Dulle and Alexus Mata
Jessica Dulle and Alexus Mata are undergraduate students in the Anthropology Department at the University of Texas at San Antonio (UTSA). Over the Spring 2022 semester, they completed an internship with the Curation and Collection Management staff at the Center for Archaeological Research (CAR). A part of their hours focused on cataloguing and storing collections from Baker Cave. The Baker Cave collection resulted from a series of excavations conducted from the 1960s to the 1980s on a private ranch in Val Verde County, Texas in the Lower Pecos Region. The collection is extensive and well preserved. Due to this preservation, our staff and interns are able to work with a variety of artifacts, including fibers and textiles, that date as far back as 10,000 years before present (BP).
Archaeological Context
Baker Cave (41 VV 213) is located high up along the cliff side on the west bank of Phillips Creek, a tributary of the Devils River (Word and Douglas 1970:4). Four excavations were conducted at Baker Cave over a 23-year period. The first of these excavations was performed in 1962 by James Word with the Texas Archaeological Research Laboratory of the University of Texas (UT) at Austin (Word and Douglas 1970:1). After completion of a small preliminary investigation at the Baker Cave site, the determination was made to conduct additional, more extensive excavations to gain a full understanding of the findings. Word revisited the site an additional eight times over a four-year period, which concluded in 1966 (Word and Douglas 1970:1). The second excavation was performed by UT Austin graduate student John Greer and his team in 1968 under the supervision of Dr. Dee Ann Story (Hester 1978:1). The final two excavations of Baker Cave, in 1976 and 1984-85, were directed by Dr. Thomas Hester from UTSA and Robert F. Heizer from the University of California Berkeley. The excavations were sponsored by Earthwatch Inc. of Belmont, Massachusetts and UTSA CAR (Hester 1978:1).
Due to the lack of temperature fluctuations in the cave, cultural materials were unaffected by outside climactic shifts. Additionally, soil compaction by human and animal activity over occupation levels helped to preserve the artifacts. Cultural material in the collection includes fibrous materials that have been modified into netting, sandals, baskets, and floor mats. In addition to well-preserved plant materials, animal remains including bone and hide were also recovered. Faunal remains in the collection include a deerskin pouch and bone awls used to puncture holes into hide. Additionally, a couple of carbon 14 samples that were gathered from a hearth were used by researchers for carbon dating analysis. The analyzed samples dated to 6960 B.C. and 7080 B.C. (Word and Douglas 1970:101).
3-D Modeling
During the process of cataloguing Baker Cave’s extensive collection, a very interesting artifact, a quid with prominent dental impressions on one side, was found. The collection contains a large amount of quids. A quid is a conglomerate of fibers from different plant leaves, including yucca, agave, and/or cornstalk, that were masticated, then discarded. Quids were commonly chewed for sustenance. Paleo-Americans needed extra nutrients and carbohydrates that they could not attain from the environment. Per Leblanc et al. (2007), quids are a significant source of ancient DNA.
Jessica and Alexus took multiple photographs of the quid to construct a 3-D model. The modelled quid is 21.33 mm wide, 42.13 mm in length, and 10.73 mm in height and weighs 1.19 grams. This particular quid was chosen due to a distinct dental impression, possibly the (pre)molars, on one of its sides. This was an astounding discovery! There are indications of dental impressions on the opposite side as well but they are not as clear. We are hopeful there will be others quids in the collection with identifiable features. Click here to see the 3-D model of the quid.
Significance
Several reports have been compiled that include analysis of the recovered artifacts, flora, and fauna; theories of climactic shift and food availability based on those shifts; general information regarding the site and its surrounding area; and archaeological investigations of the site itself. Since the completion of two published reports (Word and Douglas 1970; Chadderdon 1983) and multiple presentations, additional carbon dating has been completed that pushes the date range back to 10,000 years BP (Hanselka et al. 2018). Baker Cave artifact curation is continuing at UTSA CAR as a part of their initiative to rehabilitate older archeological collections.
References
Chadderton, M.F
1983 Baker Cave, Val Verde County, Texas: The 1976 Excavations. Unpublished Thesis.
Hanselka, J.K., R. Mauldin, L. Kemp, and C. Munoz
2018 Nut Resource Use at Baker Cave (41VV213) in the Lower Pecos Canyonlands. Poster presented at the 2018 Annual Meeting of the Texas Archeological Society.
Hester, T.R.
1978 Early Human Occupations in South Central and Southwestern Texas: Preliminary Papers on the Baker Cave and St. Mary’s Hall Sites. Manuscript on file at CAR.
LeBlanc, S. A., L.S.C. Kreisman, B.M. Kemp, F.E. Smiley, S.W. Carlyle, A.N. Dhody, and T. Benjamin.
2007 Quids and Aprons: Ancient DNA from Artifacts from the American Southwest. Journal of Field Archaeology, 32(2), 161–175. http://www.jstor.org/stable/40024664.
Word, J.H. and G.L. Douglas
1970 Excavations at Baker Cave, Val Verde County, Texas. UT Austin Texas Memorial Museum.
