Teaching aid.

[tomf]

Found this big obsidian spall.

This is a preform in the purest sense.

It's fresh off a core but somebody has started to work it at the tip.

Interesting to see that it's approximately knife shaped and this might be confirmed by close examination of the tip.

It looks like it was to be serrated on the top side and straight edged on the cutting side.

A couple of flakes have been removed three quarters of the way down on the right hand side.

I think this helps to read the intended shape.

Bulb of percussion sits at base.

Also seems to be abraded on the top side to create striking platforms - but I'd like a knapper to explain that part to me....










Hopefully this gives some insight on how these obsidian artifacts were made.

[Kentucky point]

Funny you should post this, because I worked on a spall exactly like this this afternoon. It broke.

That is what happens when you take your hammerstone, and knock a spall off of the parent rock. So easy, a cave man could do it... and they did. It's weird how they never finished it.

[tomf]

1/4" is awful thin.

It can be done, but it can't be easy.

I seldom find really thin pieces - I have a handful which are mostly small too - but the best made stuff I've found it medium to thick.

I don't know if that reflects the cultures or the lithic...

High quality obsidian must be one of the better materials to work (I imagine) as it shatters so predictably and can be very pure in composition, but not all stock is equal, and I wonder if working thicker forms increased the chances of completing a piece without an accident?

Maybe they saved the fancy stuff for ceremonial or status items. Which would make them rare and, naturally, harder to find.

Often sense that these people were expedient by nature and circumstance and often chose function over form.

Yet, when they wanted to, they could be proper artists.

Thanks so much for explaining about isolating platforms.

I'm keen to understand how these things are done, but too lazy to try for myself.

As for why this spall was abandoned, we can only speculate; maybe something disturbed or distracted the process.

[Kentucky point]

1/4 thin is thin, but not thin enough, lol! I try to "sweetwater" my bifaces, as in copying the sweetwater biface, which had an 18-1 ratio of width versus thickness.

[Broken Arrow]

Not so sure about creating a platform to remove the ridge. Alot of Tom's pieces, especially the more hydrated ones, he shows have a bit of a ridge to them if I remember correctly. Also, if I were going to try and remove the ridge, I would want the platform on the ventral face so I could strike it to remove flakes off the dorsal face. If these are platforms, they seem to be setup to remove from the ventral face. Another explanation for the flaking could be that they just didn't need to make a knife at that time and a little edge flaking would do the trick, simple expedience. Or possibly lithic conservation was the aim. Perhaps it was during a time when material was running low and gathering more wasn't an option at the time.

[SurfaceHunter]

I find cobbles like that Tom might of been testing the rock to use at a later time

[tomf]

Maybe so.

I'm surprised to see the serrations and fine flaking on the tip.

I had assumed they would rough out the form before more detailed work like the edges.

The couple of flakes low down on the side may be a guide for how this piece was intended to be shaped.


I think this spall was possibly struck at the quarry.

I've never found cores large enough to have produced a flake like this so assume they kept the big stuff at the quarry.

Too much labor to carry large rocks down, I suppose.


So many reasons to like this artifact for what it can teach me.