Archaeological Chemists & Chemical Archaeologists: Working Together in the Lower Pecos Canyonlands, TX

Summary

This research is a collaboration between chemists and archaeologists to study the ancient mural paintings of the Lower Pecos. Using two independent methods, we are able to provide reliable age estimates for rock paintings. To obtain direct dates, we oxidize organic material in paint layers using plasma oxidation followed by accelerator mass spectrometry radiocarbon dating. For minimum and maximum ages, we isolate calcium oxalate in overlying and underlying accretion layers for combustion and radiocarbon measurement. Direct dates for three paint samples at Eagle Cave are statistically indistinguishable, suggesting the mural was painted as a single composition. In addition, chemical analyses identified rock shelter accretions as well as the mineral pigments used by ancient painters. Methods used include Fourier transform infrared spectroscopy, X-ray diffraction, and portable X-ray fluorescence spectroscopy. The combination of archaeological observations with physical science techniques offers a comprehensive recording methodology. As new high-resolution excavations are underway at Eagle Cave, the rock paintings can now be studied alongside excavated cultural deposits to provide a more complete understanding of this hunter-gatherer society.

This Resource is Part of the Following Collections

• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)   •
• Investigating a Ten-Millennia Record of Hunter-Gatherer Lifeways in the Northeastern Chihuahuan Desert

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Record Identifiers

Abstract Id(s): 14924