Obsidian blades

Another technique that has been used for dating obsidians, albeit only those that were heated in the past, is the fission track technique (see Textbox 26) (Fleisher et al. 1975). Fission track dating was used, for example, to date the time when an obsidian knifeblade found at a cave in Elmenteita, in Kenya, was heated (see Fig. 24). Since the shape of the blade was distorted, it was deduced that the blade had been heated to a temperature sufficiently high to partially melt it. 

Eleven obsidian objects from Tepe Yahya, composing about one-half of the excavated obsidian, were analyzed. The obsidian was an unsorted sample from two seasons of excavation, and is taken to be representative of the entire collection. All the Tepe Yahya obsidian, seven blades and four flakes, are of the utilitarian type. No obsidian luxury items were reported. 

Fig. 8.9 An obsidian core and two blades. This glasslike stone produces very shatp edges and was a highly desired raw material in prehistory...

Solid tissues must be homogenized, dried, ashed, and/or dissolved to produce a liquid sample prior to GF-/ AS analysis. Bone samples for determination are washed free of marrow by a strong stream of distilled water. Any existing fat or muscle is scraped with an aluminium-free obsidian scapel or blade found to be aluminium-free. The bone sample can then be processed by several methods to obtain a solution for injection into the... 

Tabares, A.N., Love, M.W., Speakman, R.J., Neff, H., Glascock, M.D. (2005) Straight from the source obsidian prismatic blades at El Ujuxte, Guatemala. In Laser Ablation ICP-MS in Archaeological Research, edited by Speakman, R.J., Nefl) H. Albuquerque, NM University of New Mexico Press, pp. 17-28. 

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