pXRF Identification of Prehistoric Lithic Artifact Material, Resource Clusters along the Lower Rio Grande

Summary

The U.S.-Mexico border region along the Rio Grande River, separating the southernmost Texas counties (Cameron, Hidalgo, Starr and Zapata) from the Mexican state of Tamaulipas, is a strategic corridor for prehistoric human travel connecting the Gulf of Mexico with the interior of the continent. The area contains a history of human presence extending over 11,000 years, evidenced by a wealth of projectile points that have attracted collectors for decades. To understand prehistoric people’s choices of raw materials for making artifacts, we have partnered with local museums and local private collectors to construct a geochemical data set, currently at ~1,000 entries, from modified and unmodified local lithic materials, using portable x-ray fluorescence to measure ratios of selected elements in each sample. We then use cluster analysis to differentiate populations of rock types, notably the wide range of chert types and volcanic rocks found in local rock and gravel units. Unique among the rock types so far identified is the El Sauz chert, with high contents of zirconium and titanium and known restricted outcrops in south Texas.

This Resource is Part of the Following Collections

• Society for American Archaeology 83rd Annual Meeting, Washington, DC (2018)

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Record Identifiers

Abstract Id(s): 22489