Making Copper Tools at Copper Archaeology Camp
Michelle McAfee - CRR Staff
On August 1-3, Kory Cooper, Associate Professor in the Department of Anthropology at Purdue University, collaborated with Ahtna, Incorporated in hosting a Copper Archaeology Camp. Participants made objects and tools by hand from native copper nuggets using stones to shape the metal and visited the Gulkana archaeology site, where thousand-year-old artifacts were excavated in the 1970s and ‘90s.
The term “native copper” is used in a geological sense and refers to copper found in its pure state - 99.9% copper. For example, the copper that was mined in the early 1900s in Kennecott was copper ore that contained other minerals. The mass had to be heated or processed to separate the copper from the other ores before it was usable. But pure, native copper could be worked into tools and objects as found in its natural state.
In the mid-1990s, Cooper was an undergrad student at the University of Alaska Anchorage, working on the Gulkana archaeology site when he became interested in copper as a research topic. He began investigating the Indigenous use of this naturally occurring pure copper in Alaska.
Many groups utilized copper, but Cooper said that based on the oral history of the Ahtna and neighboring tribes, it was the Ahtna who were credited with the discovery of native copper and the innovation of technology to use it for a variety of tools.
This research led Cooper and his graduate students to study the Indigenous use of native copper in British Columbia, Alaska, Yukon, Northwest Territories, and Nunavut across the Arctic and Subarctic Canada to get a multi-regional view of the technological innovation of copper.
The Copper Archaeology Camp in August was an opportunity for participants to learn how to make tools out of native copper nuggets and for Cooper and his grad students to interact with people in the Ahtna community. There were discussions about the Ahtna use of copper in the past, workshop activities, and a visit to the Gulkana archaeology site where a lot of native copper was found.
Cooper said participants were very interested in making copper tools. “You need a stone that’s kind of flat, that you can use like an anvil to put the nugget down on and start hammering it. Then you can see the shape change and start to get a feel for it,” said Cooper when describing the process of pounding out tools and objects from native copper nuggets.
The group mostly used stones to shape the tools, gathering rounded river cobbles of different sizes that people could play around with. They had a small fire going because it was used in the copper-working technique people developed in the past, referred to today as annealing.
To make a tool, you need a piece of metal with some malleability, meaning you can hammer it into a shape. Even the most malleable metal like copper, when you hammer on it for awhile, eventually gets compressed, and there is no room for the metal grains to slide past each other anymore, so it will fracture. Becoming brittle during this process is known as work hardening.
Before that happens, if you stop and heat the copper in a campfire, the heat causes the metal crystal structure to regrow. This is called annealing, and it can give you more time to work a raw nugget into a tool.
“People figured these things out because they made everything by hand. So just by observing how different materials react to cold or heat, they realized that this was one technique you could potentially use if you needed to,” said Cooper. And depending on what they were making, they might be able to take a nugget and cold work it into an awl for punching hides, a fish hook, or something like that in one session. He said once people get into it, they can make an interesting object or tool in a fairly short amount of time if they are dedicated to it.
The Copper Archaeology Camp visited what’s left of the Gulkana site. Cooper talked about what he found from previous research and the larger project, which is part of a National Science Foundation grant for archaeological research related to native copper use.
Much of the Gulkana archaeology site is now basically a gravel pit. People in the area have known about the site for a long time. Most of the work done in the ‘70s and ‘90s that Cooper was part of revealed that the site was occupied about a thousand years ago. In Alaskan archeology, that is relatively recent compared to sites that are eleven or twelve thousand years old.
When the archaeology work was being done in Gulkana, archeologists were down on hands and knees using a trowel, digging carefully and mapping things in place as they found them. The location consisted of cache pits where people stored food and house pits.
People built houses by digging into the ground a few feet, building up a superstructure using tree limbs, then covering it with sod, animal skins, bark, or some combination of those materials.
Camp participants ranged from twelve-year-olds to adults and were mainly from the Ahtna community, with a few people who came from the Wrangell-St. Elias National Park Service Headquarters. The group learned how archaeologists measure and document sites, took pictures of the landscape and examined aerial views to gather information about the past.
Cooper said a lot of archaeology work happened at the Gulkana site and many artifacts were excavated, but the findings were never well published, not even in an academic context. One of Cooper’s grad students, Emily Fletcher, who also attended the camp, wants to change that.
Her dissertation research is taking all of the notes and records, which exist mostly in analog form, and digitizing them, then using that to create a map and report that can be published to give people a better idea of what was found at the site.
Fletcher’s work focuses on making archaeological data on native copper more accessible to the Ahtna and Copper Basin communities, scholars, and researchers. She wants to do this through digital storytelling – creating stories around the archaeological data to bring it to life, similar to video game development. At the camp, iPads were available so participants could play around with examples.
Buster Landin was another graduate student who attended the camp and is doing research related to fishing weir technology in SE Alaska. Cooper stressed the importance of making this research, information and past archaeology work available to the Ahtna and Copper Basin communities.
“Michelle Anderson [President of Ahtna Incorporated], was very helpful in coordinating this camp and talking about how we can work together to make the previous work at the Gulkana site more accessible to people who want to know more about it. We hope to do something like this again in the future.”