Monday, July 13, 2009

Parks Update - Copper

I need to make some progress on the Parks contract this week. So far I've mostly been sourcing raw materials, like the Pacific Yew that I'll need for a bow and the quartzite I'll need for a few flake tools and scrapers. I did do a bit of wood working last week, but I'm waiting on a few new tools and some replacement parts for other tools that will speed things up alot.

Today I'm going to work on a copper awl. The awl is tiny and was probably cold hammered out of native copper. I have all the materials and tools on hand to hammer copper. Native copper and meteoritic iron have been cold hammered into tools in the arctic for at least 1000 years. Hammering will make the copper hard and brittle and so periodically you need to heat it to anneal the copper and repair the microscopic cracks that form and soften it to continue hammering. It looks like this awl was made from a flat sheet of copper that was folded and pounded into an awl with a square cross section. I'll need to make the replica in the same way in order to get the same cross section and flakey surface texture. The tricky part will be getting the point. Imagine rolling up a sheet of tinfoil and hitting it with a hammer -- it wants to squash apart into sheets rather than pinch together into a point.

In 1994, I conducted a metal detector survey on Late Dorset Palaeoeskimo sites on Little Cornwallis Island, Northwest Territories (now Nunavut). I wrote my honours thesis on the results and I was just flipping through my thesis this morning - very science-y. The sites date to within a couple centuries on either side of AD 1000. We found dozens of copper and iron artifacts throughout the site - many times more than we were expecting. The metal detector was a pretty low tech machine that we bought at Radio Shack, and it had two settings "Trash" and "Treasure". Because copper is a better conductor than iron, those settings could distinguish between the "Trash" iron and the "Treasure" copper.

Photo Credits:
Top, Middle: Tim Rast
Bottom: Jen Carroll

Photo Captions:
Top: Copper Awl - artifact to be reproduced
Middle: Annealling the a hammered sheet of copper on its way to becoming an awl
Bottom: Tim Rast surveying an archaeological site in the High Arctic with a metal detector. (I really need to get a new slide scanner - these scans don't do the photos justice.)

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