Hi all!
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Here we go! Look at these beauties. |
The other day I was around Grants, New Mexico and ran into
one of my favorite gas station novelties, gas station arrowheads!!! Ok so you may have seen them
around. A quick look at a few
attributes indicates that most flake cores were conical(ish). By rotating the stone core, these
knappers produced a series of pointed(ish) flake blanks. Most flake platforms had the ubiquitous
copper smear and pronounced bulb of percussion. These two attributes combine to indicate removal with copper
tools through direct hard hammer percussion. Next, a quick bench grinding for shape and drill press for notches and you have a shaped
stone that represents the memories of a week spent touring New Mexico.
I
was (perhaps rather morbidly) curious as to how the things would actually fly
and if they would go through ribs or not. We've seen how actual hunting projectiles rain death from the sky without mercy, so let's see what tinker-toy points do. The field school students and I bought a bunch and set off to see
what these points were all about.
Of course these are not meant for hunting, they’re souvenirs, objects
that make memories of vacations tangible. On the other hand, they will be traveling at about 85 feet per second, so there is one thing going for them.
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Setting up with Dave |
One
problem became immediately clear; the bases of these points were actually just
the un-thinned flake platform. I
had made a deal to not take a single flake off of the points so I ended up with
some gigantic hafts to accommodate these things. I gave each point the works, pine pitch glue and a fiber
wrap. A few initial thoughts as to
what might happen here: Just for fun we set a hypothesis that curved points
would snap at the apex of the curve.
Next we suspected that the thin hafting elements that were carved out to
accept the largest point bases would snap upon impact. Finally, we picked our
favorite points, placed bets and set out on our way. Hey, betting and hypothesis
testing go hand in hand, right?
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Hey, not too bad. |
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Rigged up and ready to send |
The Results
To my surprise a few points actually worked ok, not great,
not good…but ok. The hafting
elements really took a beating. As
we suspected, the thickness of some of the points made us have to widen the haft
too much and breakage happened at impact.
They didn’t all break though. I’m working on a test that measures the
tipping point for haft breakage using a diameter/internal width of haft
measurement. Things are coming
along on that but I need more darts.
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The two impact marks from a curved point snapping |
Most
of the points bounced off of the carcass with minimal damage to the
target. A few made little wounds
then snapped. The curved points
made some interesting damage patterns. First, unlike our hypothesis, breakage on the curved points appeared to occur at the junction of the haft. A slow motion camera would be awesome for looking at that! A pattern seems to exist that upon impact the curved tip snaps and makes an initial wound with a secondary impact occurring as the hafted fragment hits. Neither of the
wounds were a big deal.
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dull wound edges made by gas station points |
The
bench-ground edges of the points mashed their way through the soft tissue
between ribs and did more scraping than cutting within the wound path. The wounds are rounded about the
periphery of the opening in comparison to true hunting projectile that make a
rotating lenticular pattern. It
makes sense that these points do not penetrate far and have dull wound
paths. Sharp points allow the
momentum of a dart to continue through further than dull points that create
more friction.
Overall it pays to outfit projectile points with sharp edges
too, not just sharp ends. There’s probably a joke in there somewhere about
staying sharp and edgy.
Happy Hunting.
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These hafts are too thin |
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Before |
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After |
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...what a surprise |
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clean lenticuar wound from a bifacial projectile point |
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there was no way this rig was going to work, destined to fail |
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Bad bruise, yes. Dead? No |
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