Published: April 19, 2008 07:43 pm      

Bill Young - How deep should we look for evidence of first Americans?

Three sites in Texas have been discovered and at least partially excavated in the past 15 years yielding evidence of at least one culture older than Clovis. Most of the Clovis sites have been firmly dated to around 12,500 to 13,000 years ago. Not only did these Clovis sites yield projectile points of the very distinct Clovis type, the sites also yielded true blades and very large well- made thin preforms diagnostic of only the Clovis people.

The archeologists who have worked at some of these Clovis sites have consistently noted the Clovis people utilized a very specialized type of flint knapping when they were producing either points or blades. This technique of flaking is easily recognizable to researchers familiar with Clovis. I personally can recognize both the points and the blades but when it gets down to the chipping debris left at a Clovis site, I am only able to identify a few things.

Two sites which have produced some items found below the Clovis horizons are known as Pavo Real in Bexar County and the Gault site in Bell County. At Pavo Real a lot of Archaic material was excavated near the surface and eventually through an accidental discovery, a Clovis/Folsom horizon was discovered below the Archaic material. Clovis is considered to be about 1,000 years older than Folsom, but at this site diagnostic artifacts from both cultures were found at the same levels within the site. The general thought about this unusual occurrence says the site was occupied by both people more or less a thousand years apart, but there had not been any significant accumulation of soils or gravel on top of the Clovis level prior to the arrival of the Folsom people.

Since the site eventually produced a significant amount of Clovis and Folsom material at the same level, the archeologists in charge decided to investigate in several areas below the Clovis/Folsom horizons. And sure enough, other artifacts were found deeper in the site. However, none of the newly discovered material yielded any diagnostic artifacts such as projectile points or recognizable tools, only chipping debris. Analysis of the chipping debris proved without a doubt this material was not diagnostic of either Clovis or Folsom chipping techniques. Optical Spectrum Luminescence (OSL) dating of this lower level produced dates around 17,000 years ago. Needless to say this is considerably older than Clovis. Who were these people? Are they the first Americans? What style projectile points and tools did they make? Where did they come from and where did they go? Is this the culture which eventually evolved into the Clovis culture or are there one or more other groups somewhere in between? The questions are endless and about the time you think you might be able to intelligently answer one question, someone will think of several new ones.

The Gault site in Bell County is another site in which evidence of a culture older than Clovis has been found in several of the excavation units. Dr. Michael Collins has worked at the site for several years and found numerous artifacts dating to the Clovis time frame. In a couple of units the archeologists kept excavating below the Clovis levels and discovered chips and flakes which were produced by a culture unlike Clovis. In fact the material they discovered was very similar to the discoveries made at Pavo Real in Bexar County. Even though they did recover identifiable bones from several of the lower/deeper units, not a single piece of bone had any carbon left in the bones which would have allowed the archeologists an opportunity to run Carbon 14 dates. Once again Dr. Collins had to resort to the newer method of dating a soil horizon using the OSL dating methods mentioned above. So far OSL dating has been very successful except for the fact the plus or minus factor is much wider than with a conventional Carbon 14 date. OSL dates typically are quoted as being as much as a thousand years plus or minus. An example might be 12,000 years plus or minus 1,000. Carbon 14 corrected dating for the same soil might say 12,000 years old plus or minus 75 years. The OSL dates still allow the archeologist to establish a date for a site or a level within a site but the parameters are much wider. Gets you in the ball park but not a home run!

At Gault, Dr. Collins is trying to open up larger areas at the same time in the hopes of finding diagnostic artifacts in the levels below the Clovis material. Needless to say this requires a lot of painstaking hand troweling to slowly remove level after level down to a depth of around 13 feet. The archeologists are also having to deal with a spring fed water table moving across the valley floor just below the 13-foot horizon. This water keeps the bottom layers immersed most of the time which in turn creates a dangerous situation. With the bottom layer soft and pliable, part of the vertical walls are constantly falling into the units and archeologists are having to shore up sections. With a little bit of luck, there is an opportunity for them to discover a new deeply buried culture.

The third site in Texas was discovered last year during a preliminary archeological survey for a new lake to be built on the Sulphur River. Known as the Ralph Hall Lake, Dr. Alan Skinner and his crew were doing an initial survey of the area where the dam for the lake is to be built. One of the more common projects performed during an initial survey is to make several profiles of the exposed river bank to look for soil changes and buried soil surfaces. Let’s say around 8,000 years ago, the floodplain of the river was considerably lower than it is today. If this old surface was in place for a number of years, vegetation in the form of grasses and trees would start growing on this surface. Several years later the floodplain was filled in due to sediments washing in and settling across the floodplain forming a new surface. If an archeologist peels back the bank of the creek or river exposing all of the various sediments from the current surface to the bottom, lens of soils and clays can be easily seen and tested. Also if pieces of bone or carbon are found at some of the levels, dating can be performed which tells us the age of each old surface.

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Next week: More about the Ralph Hall Lake project