Peering into Texas's Past


Archeological Breakthroughs Lift the Dusty Veil of Central Texas Prehistory

Article and Photos by Bob Parvin

Plat

The old news about Central Texas archeology is this: Up to now, researchers have turned up as many mysteries as facts in their steady efforts to picture how Indian life fared in the region for some 11,000 continuous years.

For more than seven decades, archeological sites across this special landscape, where clean waters and wild foods usually were at hand, have tantalized those involved in scientific searches. There is no doubt that early humans here ranged deeply in time as hunters and gatherers.

But were they always successful? How did the patterns of ancient lifeways change form one end of the region to the other over the course of the millennia? What survival skills and simple technologies reached trusted perfection? How did early cultures respond to periodic shifts in climate and environment?

Was the primeval Hill Country as alluring to outlanders as a green island set off from yellowed expanses of desert, plain, shore and thornbrush? Did to reshape the identities of those who came, adapted and stayed?

Complicating the long-time quest for answers is a scarcity of prehistoric sites where cultural remains, other than durable stone artifacts, hearth rock and other lithic leavings, have been left in well-preserved and undisturbed context within the soil. Central Texas' alkaline dirt rapidly consumes soft evidence. The workings of man and nature are equally destructive.

Probing

However, breakthroughs in archeological detective work are in the offing. Some new light isbeginning to shine through the dusty veil of Central Texas prehistory. Like astronomers who will see the universe in new dimensions through the eyes of spaceborne telescopes, many of today's archeologists are fine-focusing on clues that lie beyond the grasp and vision of earlier science.

Take the case of Uvalde County Prehistoric Site "41-UV-132," recently investigated as part of an intensive field school in the southwestern Hill Country by the all-volunteer Texas archeological Society (TAS). The program was part of ongoing research in the area directed by Dr. Thomas R. Hester, who heads The University of Texas' archeological Research Laboratory (TARL) at Austin. In previous seasons, Hester's archeology students had tested the potential of the site, but not with the manpower and range of techniques now available.

The ancient campsite covers about a quarter-acre of loamy terrace along the Sabinal River near Utopia. A low, 30-foot-wide dome of fire-fractured limestone rock is dominant.

Called a burned rock midden, such telltale signs of Indian occupation are among the unique and most conspicuous of the many archeological features found throughout Central Texas. Lone middens amassed with up to 10 feet of burned rock and ashy dirt, as well mound concentrations that range across acres of natural topography, indicate human activity. Central Texas' most spectacular midden site once covered seven acres near Austin. Another site near Round Rock was a complex of 52 burned rock mounds. Both sites, which fully deserved protection as prehistoric landmarks, and which could have yielded immense new information about the past, succumbed to urban expansion and the ravages of artifact hunters.

Middens have puzzled Central Texas archeologists since they first were described in the 1920's. During the ensuing 50 years, scientists conducted scores of major excavations in efforts to understand better their age of usage, contents and purposes.

Teaching

Seldom exactly alike, some middens consist almost exclusively of heaped chunks of fire-cracked limestone. Others yield a dense rock matrix, plus such debris as flint scraps and artifacts, mussel and snail shell concentrations and, infrequently, enough ancient bone and charred materials to provide site-use dates through radiocarbon analysis. Adding to the riddle are burned rock jumbles that include well-defined pit ovens and flat-stoned hearths, says Hester.

He explains that a surge in the accumulation of burned rock middens occurred during the Middle Archaic Period (5,000 to 3,000 years ago)-times when favorable conditions seem to have encouraged gradual population increases. For thousands of years before and after this time, and to a lesser extent also during the Middle Archaic, simpler rock-lined hearths were in wide use.

Based on findings since the 1970's many experts now suggest a link between burned rock middens and the early occurrence and utilization of the Central Texas live oak savannah environment; especially plentiful with deer and acorns. Large quantities of heated limestone rocks probably were used to help neutralize bitter tannic acids from carbohydrate-rich acorn mash. But how? Water leaching, stone boiling, baking and other methods have been suggested but not as yet proven. Cooking techniques and other foods that supplemented prehistoric menus also need better understanding, Hester explains. "The more we know about middens and their uses, the clearer our perception becomes of the relationship between vanished cultures and their resource environments," he said.
Uvalde-132 became the object of new experiments to test and broaden the prevailing midden-use theories. It was a setting for "archeometry" in action, a term now used whenever traditional archeological teamwork is bolstered by scientists who specialize in trying to make sense out of the microscopic, chemical and complex physical makeup of ancient sites.

First, rather than carving the usual narrow test pits through parts of the midden, the entire crown of the burned rock dome was carefully peeled by measured layers. Time-diagnostic artifacts were recorded and collected for later analysis. Then came Wulf Gose, a UT geophysicist from Austin, to pull secrets from the midden rocks themselves with equipment used for one of the first times in Central Texas archeological work.

Gose makes his way around the site, mapping the placement of various rocks and extracting drilled core samples from them. Since fire temperatures can realign the mineral magnetism of rocks, Gose's study may determine from the gravitation of individual rock cores how the midden was originally formed. His technique promises to shed light on whether some midden sites merely accumulated as random dumpsites for prehistoric campfire litter, or if they evolved over time as either clusters of small incidental hearths, or as wide lenses of burned rock left over from repeated, large-scale food preparation. As the archeomagnetic testing process is refined, the prehistoric age and cooking temperatures of rock features may be established, Gose suggests.

Aerial view of archeological dig site

Meanwhile, Andrew Manning, one of several specialized UT graduate archeology students, hunkers down to test for chemical residues at various areas of the site. He lays out tweezers, solvents, test papers and eyedroppers. Steady-handed with tiny soil samples, he looks for high levels of phosphate, calcium and such trace elements that can help define where other domestic camp activities were centered. Soil samples bagged at UV-132 for laboratory study in Austin are run through a gamut of more intensive experiments, Manning explains.

The process often begins with simple flotation or hand-screening of fine materials, a sifting that sometimes yields tiny clues to how hunter-gatherers might have rounded out their diets with small game, fish and edible plants. But if little or no obvious evidence turns up after close examination, samples are dispatched for high-tech scrutiny.

By using a relatively new dating process called Accelerated Mass Spectrometry (AMS), Dr. Michael Collins, TARL Research Fellow explains: "Even the soils by themselves can provide answers, especially were no other materials are preserved at a site-no bone, no plants, no fossil pollen." When it scans claylike soils that absorb and radiocarbon atoms from ancient, decayed plant life, the AMS procedure can sense tiny bursts from radiocarbon isotopes. The readings help plot accurate ages for various excavation levels.

The $100,000 machine is specifically designed for establishing dates from small samples (1/10th gram), such as tiny bits of charcoal or residue clinging to ancient pottery. But it can also yield a basic "signature" of the kind of plant communities and, indirectly, the climatic conditions that were prevalent at a given time. One current AMS study is tracing the carbon atoms locked in bison bone fragments to reveal the composition of prehistoric Texas grasslands.

Years of guesswork are also winding down over some of the original uses for the multitude of chipped stone artifacts in Central Texas aboriginal tool kits. The inventory includes assortments of specially crafted utility items, plus about half of the more than 200 distinctive flint dart and arrowpoint styles found in the state.

Microscopic residues from plant and animal materials that adhere to recesses in flint andground-stone tools are now being identified from studies initiated by former UT graduate student Michael Marchbanks, traceable to individual species and lasting for ages, these insoluble fatty acid residues, or lipids, are detected and classified with sophisticated gas-chromatography and mass spectrometry instruments. When lipid residue studies are combined with microwear analysis-the close examination of abrasion patterns and sheen on stone artifacts-the purpose and function of prehistoric tools may be confirmed. For example, such studies recently have shown that certain styles of large Central Texas bifaces though to have served as dart points were actually used as knives for processing plant and animal materials.

Answers are also forthcoming for culinary secrets buried with old kitchen middens. Firerock and soils stained by prehistoric cooking yield lipid residues that will tell conclusively how and what types of meals actually were prepared.

"In years past, for lack of better understanding, we had a tendency to save the wrong kinds of materials from excavated sites," says Collins, the usefulness of fine-scale evidence often was overlooked as the interests of previous researchers were consumed by classifying artifact styles and laying out elaborate cultural chronologies, he explains.

As for the now rapidly evolving science of archeology, Collins predicts that quality of data, rather than quantity, will be the mandate of the future. "Research faces greater demands for answers, for more efficient and more economical techniques," he said.

Collins is part of a growing advocacy to revolutionize the basic methods of digging some Central Texas sites. Rather than continuing to excavate constricted vertical "keyholes" through site areas, particularly where discretely separated occupation time-levels are evident, many archeologists now prefer large-block, horizontal digging strategies, In this way, the lid can be lifted off entire areas where Indian groups camped and worked.

Elton Prewitt, an independent archeologist who operates a busy Austin laboratory, whetted interest in horizontal excavation when he brought to light whole campsite floors from prehistoric digs along the San Gabriel River I Williamson County. At sites now covered by Granger Reservoir, Prewitt unearthed patterned features where prehistoric families camped, made tools, prepared a variety of foods, warmed their wickiups and buried their dead over a four-century interval of the long Late Archaic Period (1,000 B.C.-800 A. D.). At Rowe Valley, a pecan-shaded river terrace near Taylor, also in Williamson County, Prewitt and hundreds of TAS volunteers exhumed the layout of a village left behind by seminomadic bison and deer hunters at about the time Spaniards came to lure natives to their new frontier missions.

Michael Blum has developed the kind of insights that make it easier now for archeologists to predict where such isolated, information-rich site components might be buried. A UT graduate student, Blum's geomorphology training helps blueprint the origin and composition where Central Texas' first inhabitants settled and resettled. At UV-132, Blum guided archeologists to hidden strata that yielded artifacts and hearth features of occupants who arrived more than 1,000 years prior to the Middle Archaic midden builders.

As geological formations of the past several thousand years are better mapped for Central Texas, Blum expects a clear image to emerge of the magnitude of climatic events that modified landscapes and human destinies. "Theories about a 2,000-year 'altithermal' (severe prehistoric drought period), and the effects of mesic intervals (wetter, cooler periods), will be nailed down," he said.

While the big picture of Central Texas prehistory is being rendered from streamlined archeological skills, we may assume from obvious clues that the Hill Country Indians were content with their lanes. "It's just hard to imagine many months out of the last 11,000 years when there wasn't some human use of great places like Barton Springs," said Collins of the famous spring-fed Austin waterhole. Some of North America's oldest and deepest continually occupied archeological sites have been found in Central Texas, he adds.

True, there seem to have been some dramatic shifts in the character of native societies and their technologies. archeological research has shown that there were hard times during the long Archaic Period when survival was based on anything that could be gathered for food. There were warring times in the ensuing LATE Prehistoric Period (800-1600 A.D.) when overpopulated territories constricted, as well as eras of expanded trade when Hill Country flintwork was swapped far and wide for the likes of fancy seashells and decorative pottery. There were good times when prairie grasses returned and bison flourished and when deer hunting was bountiful. And throughout the entire span of human experience, the hills and canyonlands, wooded valleys and rushing creeks of Central Texas seem to have unfailingly provided needed resources for its human populations.

Yet, it is a sad irony that while archeologists become more adept at interpreting material more precisely, less of the resource actually remains to be examined. Relic hunters and hasty land developments have destroyed Central Texas prehistoric sites by the thousands. Although collecting "arrowheads" had been a pastime for most of this century, the commercial market for Central Texas flint artifacts has grown dramatically since the 1970's.

"I'm panicked about rising site losses," says Collins, a Central Texas landowner who was distressed to find a once-pristine midden site on his property gutted by trespassing looters.

"All areas of Texas have been severely impacted by site vandalism in recent years," explains Robert Mallouf, state archeologist with the Texas Historical Commission, "But losses throughout Central Texas outscale all others. Site preservation is of highest priority."

Particularly hard hit are site areas concentrated along the arch of the Balcones Escarpment, where most of Central Texas' major metropolitan areas are situated. Although more than 5,000 prehistoric sites have been recorded in counties stretching form Waco to San Antonio, only a fraction have escaped outright destruction or some damaging effects from looters.

Recent increases in site loss are partly attributable to passage of laws by neighboring states where desecration of archeological resources in now prohibited. "Commercial site looters are shifting activities toward Texas where privately owned lands are not covered under site preservation laws." Mallouf says.

In the Lone Star State, he explains legal protection applies only to archeological sites on public lands that make up less than 10 percent of Texas' vast estate. State parklands, federal properties, city and county parks and areas where public funding is applied are shielded by antiquities laws that are backed by stiff penalties for violators. To date, San Antonio is the only Central Texas city that has broadened its tough local landmark ordinance to include costly fines for altering recorded prehistoric sites.

"Until state and local preservation laws are strengthened, it will primarily remain the responsibility of individual landowners and concerned citizens to actively protect the remnants of our state's distinctive and rich archeological heritage," explains Mallouf.

Convictions for illegal relic hunting are severe, says Larry South, manager of the U.S. Army Corps of Engineers' Stillhouse Hollow and Belton reservoirs near Temple. Acting on a recent tip from landowners, Corps rangers and local deputies apprehended two Belton looters who were fined and jailed for digging on federal property, as well as trespassing across adjacent private lands.

Ignorance is also to blame for site losses, Not long ago, a Bosque County landowner unknowingly bulldozed more than seven feet of rich archeological deposits to clear the recess of a large cliff overhang. The scooped material was used to fill ranch road washouts and potholes. The hollowed-out site became a cattle shelter.

Just around the bend at a nearly identical rockshelter site, Al Redder, an archeologist from Waco, has dedicated the past 23 years to carefully recording stratified campsite floors that date to the dawn of humanity in Texas. Sealed in clay strata some 20 feet below the surface of the rockshelter deposit, Tedder discovered the intact remains of two of the oldest human skeletons ever found in Texas. Near their 10,000-year-old bones he discovered evidence of even earlier human occupants.

"A layered archeological site like this is a huge book of knowledge," says Redder, "Rip out a page or a single chapter without carefully reading every line and the story is lost forever."

Education is the key to preserving what is left of Central Texas archeology for future generations, "who hopefully will be more appreciative of its nonrenewable information value," says R. C. Harmon of Austin, TAS president. Sixty years after it was chartered, the Texas archeological Society now operates with some 1,500 members to support the aims of scientific research and preservation. TAS teaches the skills of what Harmon calls "good archeology" to citizens of all ages, with guidance from distinguished professionals.

At the society's recent Utopia field school, while Harmon and some 500 other adult participants were test-excavating Sabinal River sites and scouting the hinterlands to document signs of prehistoric life, Neal Stilley took their kids aside to boggle young minds with authentic tales and tools from the Indian years.

A self-taught expert on Texas prehistoric lifeways and technologies, Stilley kept his little audience wide-eyed and wondering.

"I try to show the balance between the people of the past and the people of today," says Stilley of his programs for youngsters. "It just blows their minds to know that prehistoric kids studied hard too…except they learned things like social studies, biology, botany, geography and zoology as one unit of survival training from their kinfolks.

"To get along in today's world, kids are taught these same subjects in school in order to survive as hunters and gatherers in a technological age," Stilley concludes.¨

A frequent contributor to Texas Parks & Wildlife magazine, Bob Parvin recently completed the photography for the U.S. and Mexican Gulf Coastal regions for Shearer Publishing Company.


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