Obsidian Hydration Profiles Measured by Sputter-Induced Optical Emission

See allHide authors and affiliations

Science  28 Jul 1978:
Vol. 201, Issue 4353, pp. 339-341
DOI: 10.1126/science.201.4353.339


The variation of concentrations of hydrogen, sodium, potassium, lithium, calcium, magnesium, silicon, and aluminum as a function of depth in the hydration layer of obsidian artifacts has been determined by sputter-induced optical emission. The surface hydration is accompanied by dealkalization, and there is a buildup of alkaline earths, calcium and magnesium in the outermost layers. These results have clarified the phenomena underlying the obsidian hydration dating technique.