Free Obsidian Sourcing for Academic Researchers
Non-Destructive Sourcing of Near Eastern Obsidian Artifacts
Minnesota's Obsidian of Anatolia and the Near East (MinOAN) reference collection was assembled by and is currently being studied by Ellery Frahm, a doctoral candidate and research fellow at the University of Minnesota. Details about the collection can be found here. The entire collection is being charactered using electron microprobe analysis (also called electron probe microanalysis) in the University of Minnesota's Electron Microprobe Laboratory. Portions of the MinOAN collection also have been or will be analyzed using mass spectrometry and neutron activation analysis. The full collection has also been analyzed using x-ray fluorescence. In additional, the lab maintains an extensive database of chemical characterizations of Anatolian obsidian from previously published studies. The result is a collection from over 100 individual flows throughout Turkey and a rich data set for sourcing artifacts from Anatolia, Syro-Mesopotamia, and the entire Near East.
Using electron microprobe analysis, rather than mass spectrometry and neutron activation analysis, obsidian artifacts may be analyzed non-destructively. Whole artifacts can be analyzed, as shown above, without sampling so long as the artifact can fit through the airlock. Obsidian artifacts commonly have extremely smooth surfaces, so no polishing is necessary on many artifacts. There are no size-effects in EMPA, unlike x-ray fluorescence, so obsidian fragments as small as a grain of sand can be accurately analyzed. There is no induced radioactive, so analyzed artifacts are safe to handle afterward, and there is no induced chemical alteration. The only requirements are: (1) the artifact is clean and (2) a very thin carbon coat (about 0.00001-millimeters or 10-nanometers thick; for comparison, visible light has wavelengths from 400 to 700 nanometers) must be applied (for conductivity) and can be removed afterward.
The University of Minnesota's Electron Microprobe Laboratory has now alloted instrument time for obsidian sourcing using the MinOAN reference collection. This service is free of charge thanks to the lab, although a few conditions do exist. The obsidian artifacts must, of course, have originated in Turkey, Syria, Lebanon, Iraq, or elsewhere in the Near East for the MinOAN collection to be useful. Interested researchers should submit a proposal that includes the area, the approximate number of artifacts, research goals, etc. Other policies of the Electron Microprobe Laboratory will apply. Researchers at any level, from graduate students to faculty, and in any country are eligible and welcome to participate. Any researchers interested in participating or in further details are encouraged to contact Ellery Frahm.
Tuesday, July 10, 2007
