Otzi the Iceman & his axe

"Yuri Kuchinsky" wrote: Hmm... Whoever wrote this was obviously very weak in math.(clip) ^^^^^^^^^^ Also, in alternating current parlance. It should be "Eli the iceman." :-)

Only if he threw it.

Gary

No kidding. 4000 years ago was well into the bronze age. The chalcolithic was long over by then, though I suppose some people may have been forging trade copper into tools, if bronze was not available. The small amount of arsenic would not have qualified the axe as bronze, but it would have been pretty good tool copper. It is surprising that no sulfate inclusions were discovered in the blade.

Haven't reproductions of it been made via casting? I thought that casting was the method that was uncontroversially accepted?

I vaguely recall an article about this some time ago. As I remember it, one observation made from the hair (or bones?) was that it/they showed traces of arsenic, which the article said would result from long exposure to smelting and/or casting of copper containing arsenic. I doubt that smithing the copper would result in that level of arsenic in a human body.

Tom McDonald

Why's that? I had really thought that it was agreed that the copper had to be melted out from ore and then processed, most likely by pouring into a mold and allowing it to solidify.

Why do you think so?

Yuri.

Yuri Kuchinsky -=O=-

Not by Mr. Coffman! :)

He seems to be a lone holdout in this area...

Yuri.

Yuri Kuchinsky in Toronto

I'm sorry to inform you, but I think a joke flew over your head.

Well, as so often happens, Mr. Coffman has once again failed to respond when questioned on a particular point.

Why is it impossible that Otzi's axe was made from cast copper, and then cold-worked further, to shape it and to give it more hardness? Seems like a sensible thing to do, especially in light of all the other evidence I've supplied about very similar technologies from around the world,

From: Yuri Kuchinsky Subject: ancient copper casting outside N Am Date: Mon, 28 Jun 2004

Instead, Mr. Coffman launched into yet further rationalisations for why such things would have been useless, too difficult, unnecessary, etc. etc.

So this is the thing to do, isn't it? Ignore all actual archaeological evidence, and instead come up with some creative rationalisations for why such things couldn't be so...

And if the ancient peoples used to do such things in so many other places, why not also in North America (north of Mexico)? Perhaps the ancient North Americans weren't just smart enough to figure it out, one may suppose...

Regards,

Yuri.

Yuri Kuchinsky -=O=-

Since bronze was known in Egypt by around 3500BCE and Otzi mummy is believed to be about 5200 years old, it would seem reasonable that the art of copper smelting and casting may have existed in Europe at around the same time. Additionally there's evidence of copper mining on Cyprus from about 4000BCE and some suggestions that copper ingots may have been an export item.

The Egyption use of Bronze and the mining on Cyprus suggests that the art of castng may have been fairly well developed by the time in question. So far as I know you aren't going to find "native bronze nuggets".

Or maybe it flew over your head...

Yuri.

Yuri Kuchinsky in Toronto -=O=-

Yes, Jim, this sounds reasonable.

Other than Mr. Coffman, I don't think anyone would really be so surprised if Otzi's axe was indeed made of cast copper.

Well, I don't think that this matter is really as simple as that. There may be some complicating factors.

I don't think we should assume that all naturally occurring metallic copper is necessarily 99% or more pure copper. This is what is usually assumed by N American archaeologists, but any hard proof of this seems to be lacking.

I suspect that there may indeed be some "native bronze nuggets" out there. But this doesn't apply to Otzi's axe, of course.

All the best,

Yuri.

Yuri Kuchinsky -=O=-

I suspect that this is based on what we can find now in the way of "native copper". While that doesn't mean that other nuggets don't exist it does tend to indicate that they aren't, and probably weren't, commonly found.

out

There may well be, but the question is whether they were common enough to be a viable source of bronze. We know that in some areas there's a relatively good supply of fairly good copper nuggets and there are other areas (like Anatolia & in Asia Minor) where there a good deposits of naturally occuring ores containing tin as well as copper. The use of that presumes a higher level of technology that many people are willing to admit to.

There seems to be a tendency to assume that since we know the chemistry and requirements for reducing ore to a metal (and thus the difficulty) that early civilizations could not have accomplished it. In a like manner there's an assumption that they wouldn't have been able to achieve the temperature required to melt copper. However, high fired pottery (which requires similar temperatures) was a fairly well developed art around

In my mind the perfect example of this is ancient icemaking in Persia. I can't imagine that they understood why it worked, but then that's not necessary if you have the "recipe".

Another which recently cropped up in sci.archaeology is ancient 'wootz' steel which was found by modern metallurgists to exhibit 'super plastic' properties which they could neither duplicate nor understand at the time.

Eric Stevens

Yuri, I am posting from RCM. Your "Mr. Coffman" has given nothing but good input as to the metallurgical aspect of the nuances of copper casting. He knows of what he types. I agree with Gary, based on the fact that I have worked with copper for 15 years; cold, hot, and molten. And based on the fact that I also understand metallurgy.

FWIW, I also happen to be an "amateur archaelogist", and live within a few miles of Etowah.

Your inability to grasp simple chemistry excludes you from further discussion. Plonk

~Dave

Dave,

Good choice. Yuri isn't into research; he's already read all he needs to have read. He figures that anyone who disagrees with him (or who knows things he doesn't) is probably a racist, and certainly out to get him.

I've been very pleased that knowledgeable folks from RCM have taken the time to answer our questions. Gary has been more than generous with his time and expertise, and Paul's experiments were sweet.

What interests do you have in archaeology?

Tom McDonald

In fact, the fires are often reducing not oxi fires. e.g. straw and leaves are put into the fire to consume the oxygen. This is in a closed or semi-closed 'hill' of material that insulates the central heating fire and bake oven.

Those I saw in Korea that were said to be 1000 years in operation - looking at it maybe so - were long (100' or more) and ran up a hill side. Zonal temps can be made that way.

So the green sand with fleck's of copper in it - could be put in a pottery and placed in the oven for a long hot cook. The metal is reduced out and puddles under the sand and material. Separation and clean up is only needed.

The potters used metals and ores long before metal and likely ran into ore that reduced into native metal. With that, maybe someone took an extension...

Martin

Why they would not have understood why there was a difference in a reducing or oxidizing fire, the difference in the way glazes behaved wouldn't have been lost on those potters. And when using a copper or other metallic ore they probably did on occassion see metallic spec in the glaze. Given the value of metal in that time there'd be an incentive to figure out how to maximize the yield.

And running the kiln a good distance up a decent slope can create quite a draft, sort of a natural forced draft. That of course allows greater temperatures to be reached.

Yep, that's probably the way it was done. In one of the books I've got on Japanese sword making there's a description of ancient iron making techniques that's still used today for raw material for the most valuble swords made by "master swordmakers" that works like that.

Basically they make a large pit containing the fuel, ore, & flux and burn it out. The metallic iron collects at the bottom and is retrieved when the burn is finished and everything has cooled down.