Limitations of obsidian hydration dating

Radiocarbon, or Carbon, dating is probably one of the most widely used and best known absolute dating methods. It was developed by J. Arnold and W. Libby in , and has become an indispensable part of the archaeologist's tool kit since. It's development revolutionized archaeology by providing a means of dating deposits independent of artifacts and local stratigraphic sequences.

Obsidian hydration dating OHD is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufacture of stone tools such as projectile points, knives, or other cutting tools through knapping, or breaking off pieces in a controlled manner. Obsidian obeys the property of mineral hydration , and absorbs water , when exposed to air, at well defined rate. Over time, water slowly diffuses into the artifact forming a narrow "band," "rim," or "rind" that can be seen and measured with many different techniques such as a high-power microscope with power magnification b depth profiling with SIMS secondary ion mass spectrometry , and IR-PAS infra red photoacoustic spectroscopy. Geological Survey. The use of Secondary ion mass spectrometry SIMS in the measurement of obsidian hydration dating was introduced by two independent research teams in Today the technique is applied extensively by archaeologists to date prehistoric sites and sites from prehistory in California [8] and the Great Basin of North America.

Obsidian—hydration—rind dating , method of age determination of obsidian black volcanic glass that makes use of the fact that obsidian freshly exposed to the atmosphere will take up water to form a hydrated surface layer with a density and refractive index different from that of the remainder of the obsidian. The thickness of the layer can be determined by microscopic examination of a thin section of the sample cut at right angles to the surface. The hydration—rind dating technique also has been used to date glassy rhyolitic flows that have erupted more than years ago but less than , years ago. Obsidian—hydration—rind dating Article Additional Info. Print Cite verified Cite.

Obsidian hydration dating OHD is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufacture of stone tools such as projectile points, knives, or other cutting tools through knapping , or breaking off pieces in a controlled manner, such as pressure flaking. Obsidian obeys the property of mineral hydration , and absorbs water , when exposed to air, at well defined rate. Over time, water slowly diffuses into the artifact forming a narrow "band," "rim," or "rind" that can be seen and measured with many different techniques such as a high-power microscope with 40—80 power magnification , depth profiling with SIMS secondary ion mass spectrometry , and IR-PAS infra red photoacoustic spectroscopy. Geological Survey.