► New approach for measuring hydration layer with Secondary Ion Mass Spectrometry.
Obsidian hydration dating is a widely used method of determining the age of flaked obsidian by measuring the thickness of the hydration rind on a sample. The depth of the hydrated layer is a function of obsidian chemistry, temperature and time.
In order to transform the hydration rim value to a calendar age, the rate of the diffusion of water into the glass must be determined or estimated. However, in spite the accurately measured rinds beyond digital optical microscopy employing infrared spectroscopy and nuclear analysis, the traditional empirical age equation produce occasionally satisfactory results but still fail to produce a reliable chronometer.In the last ten years, secondary ion mass spectrometry (SIMS) has been employed to accurately define the hydration profile.Lithic technology was a core-flake reduction process that exhibited little temporal change.Ceramics are absent and thus technological, stylistic, or luminescent dating studies are not possible.The most important of these are chemical composition and temperature, although water vapor pressure and soil alkalinity may also play a role in some contexts.