the varga site - Texas Beyond History

advertisement
THE VARGA SITE: WHAT WE CAN LEARN FROM TECHNOLOGICAL ANALYSES OF
ARCHEOLOGICAL REMAINS
Top of page image: Leave frame for an image, no caption needed. I will send this image
later.
Hackberry.jpg: Clear spring pool adjacent to the Varga site, with rugged limestone hills
rising in the background. Prehistoric hunters and gatherers found plenty of resources in
the Canyonlands—water, game, and fuel—and called this area home for thousands of
years. Photo by Mike Quigg.
Physio-map: Physiographic map of Texas with Varga site plotted on the Edwards
Plateau, near the western margin of the Balcones Escarpment.
Road-damage; Road damage following heavy rains and flooding on Hackberry Creek.
The need for substantial road reconstruction led to cultural resource investigations and
excavations at the site. Photo courtesy of Todd Varga.
Canyonlands-quigg- Thick stands of evergreen Juniper dominate the Canyonlands
landscape today, crowing out other trees, plants, and grasses. During prehistoric times,
native campers used the wood for fuel and perhaps for their shelters. Photo by Mike
Quigg.
FigM-2 Dozens of artifacts were examined under high-powered microscopes for evidence of usewear. This artifact, initially classified as a Perdiz arrow point, was found to have been used as a
hafted perforator. The photomicrograph shows the haft portion of the Perdiz point with lateral
edge grinding of the tang. Graphic by Marvin Kay from Quigg et al. 2008.
Throughout prehistory, groups of mobile hunter-gatherers roamed across the Edwards
Plateau looking for food, shelter and, potentially, others to interact with periodically.
Although the rocky plateau appears to be rugged and inhospitable, with what one might
consider harsh environmental conditions, scant food, or other resources, many native
peoples in the past called this place home. Different groups of people set up their
camps near the clear springs or water holes carved in the limestone bedrock or along
the shaded streambanks. From that base, they would gather wood for their fires, kill local
game such as deer and rabbits, harvest a variety of plant foods, collect rocks for use in
cooking their food, and ultimately thrive within this environment. This is what happened
here at the Varga site on at least four occasions and perhaps many more times before
Europeans arrived in the area.
Named after the local land owner, the Varga site (41ED28) is located in northeastern
Edwards County just below the top of the Edwards Plateau and along Hackberry Creek.
This small stream flows into the Nueces River in southwestern Texas near the western
edge of the Balcones Canyonlands, a physiographic and ecological subdivision of the
Edwards Plateau. The region is characterized by deep, rugged, parallel canyons that
were carved through the limestone formations by southward-flowing streams. Below the
Balcones Escarpment and fault zone at the southern edge of the Edwards Plateau,
these streams flow across the nearly level Rio Grande or Gulf Coastal plains, eventually
discharging into the Gulf of Mexico. Today, as in the past, the stream valleys and
hillsides support a variety of animals and plants.
Modern vegetation is a Juniper-oak savannah with a dense to open canopy of broadleaf
deciduous and needleleaf conifer shrubs and low trees. These include Mountain Juniper
(Juniperus sp.), a species which dominates the landscape today, Live Oak (Quercus
virginiana), and Little Bluestem (Andropogon scoparius) grass. Wooded stream valleys
contain several species of oak (Quercus sp.), elm (Ulmus sp.), pine (Pinus sp.),
hackberry (Celtis sp.), pecan (Carya illinoiensis), walnut (Juglans microcarpa), and the
stream floodplains support a variety of berry-bearing shrubs are present along
Site Discovery
The Varga site was discovered during a cultural resources survey of the upper Nueces
River Natural Area near the Devil’s Sinkhole. Searching for evidence of prehistoric or
historic sites, the surveyors noted burned rock and chipped-stone artifacts scattered
over an area extending roughly 800 feet (250 meters) along Hackberry Creek. Two
dense accumulations of burned limestone, or “burned rock middens,” as well as several
“fire hearths” also were found.
Several years after the archeological survey, nature—in the form of another flood—
conspired to bring investigators back to the site for more extensive investigations of the
cultural remains. In both 2001 and 2003, heavy rains caused major flooding of area
streams and rivers and destroyed the paved road that crosses Hackberry Creek. The
Texas Department of Transportation (TxDOT) made plans to fix the road and solve the
recurrent flooding problem for local ranchers. But before roadwork began, TxDOT
archeologists inspected the location and identified a prehistoric site on the north side of
the low water crossing. To comply with state and federal laws, TxDOT then contracted
with TRC Environmental (TRC) of Austin to conduct archeological investigations at this
prehistoric site. Following fieldwork and analysis of the findings, TRC prepared a twovolume technical report that provides a detailed scientific appraisal of the archeological
site. The web exhibit you are reading is a public education outreach effort sponsored by
TxDOT intended to summarize and illustrate the findings.
Using Technical Tools
Preservation of a variety of materials enabled investigators to use technical analyses to
help understand what happened at the site in the past. The use of such studies has
expanded considerably over the last few decades. Advances in technology, equipment,
collection techniques, and understanding are allowing archeologists to bring a much
larger set of tools to bear on what is uncovered in the dirt—as well as the dirt itself.
These analyses are intended to reveal how specific information can be extracted from
the materials from an excavated site. This, in turn increases our understanding of human
behavior and enlightens us to the peoples that once roamed through the region.
In the past, archeologists made many of their assumptions about everyday activities
and behaviors of past peoples based on the shapes of artifacts and on experiments
using replicated artifacts. For example, a unifacial tool (chipped on one side) with a
slightly beveled rounded edge was recovered from the Toyah zone at the Varga Site.
Based on experiments using replicated chipped-stone tools of similar shape, we might
assume this tool was used for scraping, and thus classify it as an “end-scraper.” But by
looking at it with the naked eye alone, we cannot tell you what materials it scraped, or if
this particular specimen actually was used for something else. To extract more specific
information, an archeologist might submit the tool for high-power microscopic
examination, or use-wear analyses, or other types of analyses. By these means we
might find that the tool was coated with a glossy silica residue typical of processing
plants. Or there might be bits of hair embedded along the tool edge, indicating contact
with animal hide. Because of advances in radiocarbon dating, some of these miniscule
samples might also be dated. Using these types of analyses, our knowledge about this
single tool expands considerably from the simple term, “scraper.”
In This Exhibit
Unlike most others on Texas Beyond History, the Varga Site exhibit focuses largely on
these and other techniques, the interdisciplinary sciences involved in 21st century
archeology. The Field Investigations and Findings section provides an overview of the
field work and evidence recovered and incorporates the various findings into a cultural
chronology for the site. How Do We Know? provides a closer look at eight of the
technical analyses employed and the specific findings used to help interpret the site. For
students and general audiences alike, this section provides a more detailed view of the
methodologies involved and the types of information which can be extracted from
various types of samples. Old Assumptions and New Insights considers what has
been learned and what needs to be reconsidered or improved in the future. Credits and
Sources provides background on the authors and additional sources to consult for more
information.
Download