Prismatic blade
This article may be too technical for most readers to understand.(November 2010) |
In
Prismatic blades were used for cutting and scraping, and have been reshaped into other tool types, such as
Morphology
Prismatic blades are often trapezoidal in cross section, but very close in appearance to an isosceles trapezoid. Triangular blades (in cross-section) are also common. The ventral surface of the prismatic blade is very smooth, sometimes bearing slight rippling reflecting the direction of applied force and a very small bulb of applied force (indicative of pressure reduction). Flake scars are absent on the ventral surface of these blades, though eraillure flakes are sometimes present on the bulb. The dorsal surface, on the other hand, exhibits scar ridges running parallel to the long axis of the blade. These facets are created by the previous removal of blades from the core. The proximal end contains the blade's striking platform and its bulb of applied force, while the distal end will consist of a snap break, a feather termination, or a stepped termination.
Production
It is in this manner: First they get out a knife stone (obsidian core) which is black like
jet and 20 cm or slightly less in length, and they make it cylindrical and as thick as the calf of the leg, and they place the stone between the feet, and with a stick apply force to the edges of the stone and, at every push they give, a little knife springs off with its edges like those of a razor.[4]
The production of prismatic blades creates not only a very standardized final product, but also a standardized waste assemblage.[5] The analysis of obsidian debitage can reveal whether or not prismatic blade production occurred at a site and, if it had, what stages of production the process included. In other words, the types of manufacturing waste present (e.g., rejuvenation flakes and/or blades, platform rejuvenation flakes, etc.) at a site can inform archaeologists about the stage in which blades were being produced.[6]
Notes
- ^ Hester et al. (1971)
- .
- ISBN 1623033934, 9781623033934, google books
- ^ Hester et al. (1971)
- ^ Clark and Bryant (1997)
- ^ Clark (1997)
References
- Clark, John E. (1997) Prismatic blademaking, craftsmanship, and production: an analysis of obsidian refuse from Ojo de Agua, Chiapas, Mexico. Ancient Mesoamerica 8:137-159.
- Clark, John E., and Douglas D. Bryant (1997) Technological typology of prismatic blades and debitage from Ojo de Agua, Chiapas, Mexico. Ancient Mesoamerica 8: 111–136.
- Hester, Thomas R., Robert N. Jack and Robert F. Heizer. The Obsidian of Tres Zapotes, Veracruz, Mexico. University of California Archeology Research Facility. No. 13 pp. 65–131, 1971.