Date Approved


Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)



Committee Member

Ruth Ann Armitage, Ph.D.

Committee Member

Heather Holmes, Ph.D.

Committee Member

Rosemary Brady


A black, shiny coating overlies rock paintings in Little Lost River Cave no. 1, located in southeastern Idaho. If this coating is the result of human activity within the cave – a condensate from cooking fires, for example – then a radiocarbon date on the coating would provide a minimum age for the underlying paintings. The work reported here was undertaken to test the assumption that the coating has an anthropomorphic origin. Using pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) and thermally-assisted hydrolysis/methylation-GC-MS, we have compared samples of the black coating from Idaho to humic acid, a geologic material; an experimental cooking residue; and amberat from packrats. The results show that the coating is not amberat but bears the most similarity to humic acid, which would indicate a geologic origin for the coating. The age of the coating, then, is not related to the age of the paintings.

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Chemistry Commons