Human Behavior from Rocks and Lasers

30 Days of Tennessee Archaeology 2015, Day 6

Ryan M. Parish, PhD
Department of Earth Sciences,
University of Memphis

Five gallon buckets of chert samples from summer field work in AR, OH, IL, IN and TN.

Five gallon buckets of chert samples from summer field work in AR, OH, IL, IN and TN.

The only thought in my mind as I inched up the nearly perpendicular hillslope carting a five gallon bucket of rock was; “don’t spill out any of those slick nodules.”  My concern at the time was the samples I had just procured from a newly located outcrop of Upper St. Louis chert, fine grained and dark in color unlike anything I had collected on prior occasions.

I wonder sometimes if my passion for archaeology, specifically prehistoric chert procurement and consumption, trumps more practical concerns such as hospital visits without health insurance (graduate school years).   However, the love for discovery in the field of archaeology drives many of us out into the tick infested backwoods with heat indexes over 100 degrees.  I also marvel at the hours upon hours of monotonous work which went into cataloguing and labeling some of the private collections I’ve seen, the worthwhile price paid for maintaining irreplaceable scientific data.  The love for discovering our collective past takes us along many avenues, for me its deciphering human behavior from “rocks and lasers.”

Reflectance spectrum of Burlington chert in the visible, near- and middle infrared regions.

Reflectance spectrum of Burlington chert in the visible, near- and middle infrared regions.

The objective of the research is to decipher past cultures through sourcing chert artifacts back to the location at which the raw material was procured.  Presently I use two instruments to gather spectral data from geologic samples and chert artifacts in the visible, near infrared and middle infrared regions.  The resulting spectra produces a series of peaks and valleys related to the differential absorption/transmission/reflection of portions of electromagnetic radiation (visible light and infrared waves).  The shape of the unique spectra is determined by a number of variables including the sample’s atomic and molecular structure.  Therefore, the spectrum of any particular chert artifact can potentially be matched to a geologic deposit of chert.  This straightforward approach, often referred to as the “fingerprint analogy” in sourcing research, is a rarity.  More accurately the sum variation of the chert artifact is matched to the sum variation of the geologic deposit as singular diagnostic attributes seldom exist.

Discriminant function 3D scatter plot of chert types and Late Paleoindian bifaces analyzed.

Discriminant function 3D scatter plot of chert types and Late Paleoindian bifaces analyzed.

If the source of the raw material used to manufacture the artifact can be determined, we then are able to test hypotheses regarding a wide range of prehistoric behaviors including trade, migration, technological organization and multiple other lines of inquiry.  Specifically, to date I’ve focused on two applications, determining the chert source for a sample of Mississippian ‘swords’ and the source for Late Paleoindian/Early Archaic bifaces on a handful of sites in Hardin County, TN.  The chert sourcing studies have given us greater insight into the cultural dynamics of both chiefdom and hunter-gatherer societies.

Mississippian “Swords”

Mississippian chert sword.

Mississippian chert sword.

Non-destructive spectral analysis upon a sample of thirty chert swords found at sites from central and eastern Tennessee determined that both Fort Payne and Lower St. Louis (Dover) chert were used in their manufacture.  Fort Payne chert was the dominant material type in the sample analyzed.  The study also demonstrated that although local deposits were exploited, there was also some evidence for long distance acquisition.  The results of the sourcing study are interesting as the material appears visually to be from the well-known Dover quarry sites in north central Tennessee.  However, the discovery of multiple raw material sources for the symbolically charged “sword” artifacts gives us information regarding the social value or ‘exoticness’ of chert in symbolic weaponry.  Raw material selection may not have been as important to symbolic function as previously implied.  The results also speak to the apparent “economic” decentralization of symbolic weaponry manufacture and distribution.  Additionally, the source data gives us a proxy to further investigate inter-regional interactions via exchange.

Terminal Pleistocene Hunter Gatherers

Thanks to the detailed provenience information upon surface collected artifacts by the late Jim Parris*, we have an excellent dataset of newly recorded Late Pleistocene and Early Holocene sites in Hardin County, Tennessee.  The Paleoindian materials of his collection are only one component of multiple spanning nearly the entire prehistoric record of the Lower Tennessee River Valley.  Spectral analysis of over 500 Late Paleoindian bifaces from 14 sites shows some interesting chert procurement patterns.  Three main source regions were identified.  The majority of the bifaces were sourced to local deposits of Fort Payne chert along the Western Highland Rim.  A second portion of the bifaces was sourced to Fort Payne chert from deposits upstream in northern Alabama.  Finally, a significant portion of the bifaces was manufactured from Fort Payne chert in southern Illinois.  Though these initial results require further investigation, the raw material patterns observed point to periodic aggregations of three groups.  The location is interesting from an environmental perspective as the Tennessee River flows down from the Highland Rim onto the Coastal Plain physiographic province possibly rich in resources and attractive for hunter-gatherers.

Three main Fort Payne source regions possibly signifying periodic aggregations of Late Paleoindian/Early Archaic macro-bands.

Three main Fort Payne source regions possibly signifying periodic aggregations of Late Paleoindian/Early Archaic macro-bands.

Continuing research will potentially clarify our understanding of how prehistoric chert consumers utilized tool-stone resources and interacted with others.  Currently, the chert type database contains over 4,000 samples from IL, IN, OH, KY, TN, AR, AL, MS, and GA.  The addition of more sampled deposits will add to our knowledge of past lifeways.

*Editor’s Note: Jim Warner Parris was posthumously awarded the Tennessee Counsel for Professional Archaeology’s Avocational Lifetime Achievement Award in 2015.

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