Spirit in the Wind
Rick abo knapping
at the annual "Archaeology Awareness Days"
in Mitchell, S.D. at the Archeodome with Dr. Adrien Hannus, and
Tim Gillen, both archaeologists with the Augustana
Hammerstones: Hard percussion tools. Hammerstones of various sizes and hardness are generally used in the intial stages of spalling, such as when you are breaking into a nodule for the first time, or in the initial bifacial reduction process. They are also commonly used to produce flakes (also called spalls), from which points can than be made. Hammerstones generally produce a flatter flake than antler billets, but a good knapper can produce nearly identical flakes with either hammerstones or billets.
Pressure Flakers:Pressure flaking is used to set up platforms for percussion, and also on the final stages of certain points to impart a sequential flake pattern, as well as thinning on smaller points. Pressure flakes are much smaller than those removed with percussion. Deer and elk tines are shown here, some with a leather and wood handle.
Spalling: Large spall removed with hammerstone using a slow, straight-in blow with follow through. Impact point indicated by red circles
Spall Impact:Platform (beveled edge used as impact point for percussion or pressure flaking) on nodule showing refitted spall with red circle indicating point of impact
Republican Strike Pt.: Flake detached with antler billet. Red circles indicate point of impact.
Soft Percussion Flake: Notice the curvature and thinness of the resultant flake. Result is typical of billet percussion.
Direct Freehand Percussion With Billet: Use a steady and consistent swing when doing freehand percussion. Hold the stone loosely, and do not let the hand drop upon impact, a common mistake. Some people prefer to do percussion while the point is laying on your padded leg.
Pressure Flaking:Notice the hand holding the stone is locked into the inside of the left leg, and the right hand with the pressure flaker is pushed down onto the right leg. This allows you to help compound the leverage by squeezing in with both legs.
Pressure Flaking Close-Up:The tip of the flaking tool should rest on the beveled edge (platform), then push with considerable force straight in (called loading), next use an outward snapping motion with a follow through push to detach the flake.
Overshot Flake: Overshot flakes were used extensively in Clovis technology as a means of thinning a biface with just a few flakes, while also leaving it fairly flat. The picture shows the detached overshot flake and the outlined area where it came from on the biface. An overshot or outrepasse, initiates on one edge and expands to cross the face completely, and remove a portion of the opposing edge, usually a square edge that hasnít been refined yet. The arrow indicates the direction of travel of energy, while the circles indicate the impact point of the antler billet. With this technique they were able to thin an average size biface with just several flakes. Few knappers today can consistently produce true overshot flakes.
Georgetown Nodule: A whole nodule can either be worked down into a biface from which a point can be made, or you can remove spalls from the nodule to produce points from, or a combination of these can be done, with removing some spalls and then making a larger biface from the remaining core. Much is dependent upon the original nodule as to how the reduction process proceeds.
Spalls From Georgetown Nodule:A smaller hammerstone was used to remove these spalls from a nodule of Georgetown (Texas material). Several points can be made from a nodule.
Georgetown Biface: A spall worked down with a smaller antler billet percussion into a thinned biface (flaked on both sides), which is now ready for some pressure flaking
Holding Technique for Pressure Flaking:Notice the placement of the fingers holding the preform in position using only the edge. This is to prevent snapping the point in two by holding too much pressure down in the center. This same hold can also be used for notching.
Georgetown Preform: The biface after it has been shaped and thinned with pressure flaking and now ready for notching.