Seppo Renfors wrote:

Tom McDonald wrote:

Seppo Renfors wrote:

snip

http://www.dayooper.com/Networks.JPG

The copper may well be 99% pure - what about the rest? It isn't every
day people find huge lumps of pure copper without impurities embedded
within it. This is the dilemma that people bypass and ignore.

This has a good story about the Great lakes Copper deposits.
http://www.geo.msu.edu/geo333/copper.html

[..]



Seppo,

Thank you for the urls.

From the second link:



Hang on a sec. What about the first? After all it is THE more
important one.

Seppo,

I don't think so. That's why I focused on the other url.


http://www.dayooper.com/Networks.JPG

You tell me how the hell you can make an axe head out of that! You are
in total denial about this problem.

I don't know the matrix enclosing the copper in this sample.
However, as you note below, stone hammers would work fine to
crush rock containing the copper. Then the copper bits could be
picked out of the debitage.

What is the problem? No one has maintained that all the copper
used was in the form of pure copper nuggets.



"Michigan’s copper deposits were remarkable for their quality
and purity. Bands of native copper were contained in outcrops 2
to 8 miles wide and of varying depth. The surface deposits first
attracted the notice of Native Americans who dug out the easily
accessible chunks and fashioned copper tools and adornments from
them."


Do you REALLY believe they were cliffs of PURE copper?

No, of course not. Don't be silly.

Note the words
"were contained in". Then see the Networks.JPG and you will get an
idea of the meaning of the words.

What is your point? We know that the folks back then
eventually had to mine the copper. We know the tools they used
to do so. Had most of the copper been in large lumps, the tools
used for mining would not have been large stone hammers, wedges,
fire, etc.

As Gary has pointed out, it's a bitch to cut pure copper, even
with steel tools. Smart folks, like the Indians of those days
were (still are, BTW), would most likely have preferred to
extract the copper in more manageable sizes.


I am aware of one piece of copper 17 ton of it (Yank ton presumably -
a short measure). It was found on the bottom of Lake Superior. I'm
also aware of another large find of several tons, but a VERY long way
underground in a modern mine. Neither kind of find was available to
the native people.


And nor would they have preferred them if they were available.
There is a huge chunk of copper still in a mine, which the
ancient Indians tried to extract, but appear to have given up as
a bad job. Still, they seemed to do OK without it.

BTW, what is your fascination with size here? It's not really
relevant.

So mining appears to have *begun* where copper deposits were on
the surface. This makes sense, as there was also drift copper
(over a wider area than just the UP mining areas), and folks
early on seem to have selectively used lumps of copper that
needed no processing. While this might not have been an every
day event, it clearly was common enough to produce many of the
copper artifacts in the region.

As to mining the copper:

"They [Indians] dug pits in the ground and separated the copper
from the stone by hammering, by the use of wedges, and,
possibly, by the use of heat. Thousands of hammers have been
found in and about the old pits."


The claimed method is not fact - only assumption. The "fact" is the
finding a lot of "hammers". They are only proof of pounding or
hammering - which can mean crushing of rock containing the copper.

Yes, that too. Or do you imagine that the hammers were
single-purpose tools?


It seems that these folks picked the visible copper out of the
debitage after beating the bejesus out of the rock. That seems
reasonable to me, as there seems to have been quite enough such
copper available to make other methods of extraction unnecessary.

The dilemma you refer to does not seem to exist.



THAT is nonsense. I have provided you with a good example of the
nature of it. It isn't the first time I have done it either - and
haven't even had to use the same pictures.

Re-read (read?) what I wrote directly above the bit you went
off on.




Indian people
developed the technology they needed to extract the resource
they wanted.


Obviously, only you don't know what method they used. Nobody has
bothered to find out.

Ever heard of 'archaeology'? Or haven't *you* bothered to find
that out?



They may have developed copper casting technology
as well. Since smelting wasn't necessary, casting would have
been a stand-alone technology. It wasn't beyond the capacity of
the Indians of the upper Great Lakes; but it also wasn't necessary.


Then you can perhaps point to the huge piles of discarded copper that
was useless because it looked like that stuff in the first URL. There
have been vast amounts mined by the native people - where are the
rejected copper piles?


Some is still there. I assume, but do not know, that modern
prospectors and miners would have processed such piles, as they
would probably have been a good source of copper for smelting.
Or do you think that respect for the past would have prevented
the modern copper industry from utilizing that resource?

If the copper is pure is not known because nobody has bothered to find
out.

And yet, they did. If you aren't going to read this thread any
better than you appear to have done in this sentence, why post?

Silver does exist with/alongside/embedded in with copper in that
area - as are other minerals, including arsenic.

Sure. Copper artifacts have been found with just those
inclusions. However, silver isn't found in them as an alloy
(which might happen if the material were cast), but as
inclusions (which would happen if the copper-silver cobble were
worked by smithing).

Tom McDonald