Newbow, what did you think of the article? Do you buy such things as, "velocity-dependent microfracture features"?
I've seen lab results from tests involving controlled fracturing (dropping a percussor from various heights onto an objective piece). They are interesting but there are so many variables to consider. "Velocity-dependent microfracture features", for example, seems hokey to me.
Hokey - Noticeably contrived; artificial.
I know that I can be VERY annoying, but please bear with me.
(I only do this because I've admired your level-headed posts and I want to tap into your experience).
First of all, it doesn't take much force to cause a flake detachment on obsidian (the material in question). Second, the more massive or immoveable the object being struck, the greater the force of impact for a given velocity. Third, tremendous velocities can be generated with hand held objects. Then there are obvious questions: How do we account for moving targets? Or, as part of an overall strategy, were the targets usually running away from or charging toward the hunters, for example? Were the projectiles thrown horizontally or dropped from an elevated perch (e.g. high up in a tree)? Or could the stone points have been placed on the tips of stakes at the bottom of a pit? What about a deadfall trap with a heavy rock above and sharp stones below? The heavy rock might make contact with the tips of the pointed stones, for example. We must also keep in mind that hunting methods that are unethical or illegal today were probably common if not preferred back in the day.
I just don't see any clear way for "velocity-dependent microfracture features" for a given artifact to tell us anything about how the artifact was used. Maybe the artifact was traveling with a high velocity when it got damaged? Maybe not? The writers believe they can determine the hunting strategy from the projectile. IMO, that would be like trying to see what was written by looking at the pen.