News Release from the U.S. Army Garrison
Saving a cultural heritage: Archaeologists race seasons, construction deadlines to understand, preserve artifacts at pre-historic site
DELTA JUNCTION, Alaska -- Nine thousand years ago, the pyramids of Egypt were millennia from construction.
In Europe, the massive sarsen slabs that today make up Stonehenge were likewise still nestled snugly in their native bedrock, awaiting human hands to bring them to their full potential.
In Alaska, near present-day Delta Junction, a small group of hunter-gatherers — probably the ancestors of modern Athabascans who still inhabit the area — claimed a small hilltop as a temporary camp.
In between forays for moose and caribou, they used basic stone tools to scrape fat, meat and hair from the hides of previous kills.
Specialized workers prepared food in a separate area of the camp, while others sat and patiently chipped razor-sharp slivers from chunks of stone for blades or other tools.
Now on the same site, which sits in U.S. Army Garrison Alaska’s Donnelly Training Area, another group of seasonal workers strive to find any remnants of the previous inhabitants.
Slowly and diligently, they scrape away thin layers of soil, peeling away centuries of accumulation with hand trowels, brushes and dustpans. This band of roughly 20 archaeologists is charged with excavating the site and saving the artifacts they find there from the pace of Army transformation.
When this dig is completed, their trowels and buckets will be replaced by the blades of bulldozers and other heavy construction equipment working to create a target area for the new Battle Area Complex Combined Arms Collective Training Facility.
Excavation of the site began last year, according to Aaron Robertson, the lead archaeologist for the dig.
“When you make a stone tool you have these tiny little flakes that come off. They’re the bi-products of manufacturing,” Robertson explained. “Whenever you manufacture a tool, especially a bifacial projectile point or an arrowhead, you produce lots and lots of these flakes.
“When you find them in a concentrated area, we usually refer to that as a lithic workshop. That’s what we started to find in this area.”
The site is broken down into meter squares, and then divided into quarters again when excavation begins. After the surface root mat is removed and decaying vegetative material brushed away, archaeologists gently scrape away soil a millimeter at a time.
Any artifacts are identified and plotted in the three-dimensional map of the site, then carefully removed, catalogued and prepared for further study after this season’s field work is completed. All the soil is collected in buckets and carried to shaker boxes where it is screened through a fine mesh to find any artifacts which might have been missed.
“The last week of last year’s field season, we came across a unit that had bone fragments in it,” Robertson said. “You usually find the coolest things in the last week.”
He noted this was an important find because the makeup of the soil in the area makes bone preservation rare.
“Bone doesn’t survive in Interior Alaska very well, because of the soil type,” he explained. “The spruce trees make the soil very acidic, so if bone is in the ground it doesn’t survive very well.
“Usually it has to be altered in some way,” he said. “If you cook it or if you burn it, it changes the chemical makeup of the bone and increases its chance of preservation. The ash and the charcoal basically neutralize the acidity.”
When work centered around the units where the bone fragments were found, the team discovered a pre-historic hearth — another important find.
“This was an ancient fire,” Robertson explained as he lightly pointed to different pieces of the excavation. “You can see the bone fragments on the top, this is a big piece of charcoal, this is charcoal and this discoloration here is ash.”
He said the next step is to create a three-dimensional map of the hearth.
“Then we’ll basically destroy it while we excavate it, so we’re slowly recording it,” he said. “We photographed it, we drew it and after we’ve done the three-dimensional map we’ll pull out these big pieces of bone that are in there and the charcoal and we’ll send away the charcoal for dating so we’ll know pretty much how old it is.”
So, how old does he think the site might be?
“They can be older than 8,000 years old, the type of artifacts that we’re finding, but they can be much younger as well,” he said. “But the type of tools that we are finding here fit in with the chronology of Alaska starting 8,000 to 9,000 years ago.”
That timeframe marks the change from the Pleistocene to the Holocene epochs, Robertson said.
“The Holocene is the modern era, and the Pleistocene is dominated by mammoths and a totally different type of fauna,” he explained. “The animals that occur in the Holocene are the same animals that we have today (like) your moose, caribou and sheep.”
Robertson said he expects to find the site was occupied sometime during the Holocene. He figures the bone fragments are from big game mammals such as sheep, caribou or moose, but noted earlier bones found at the site included remains of snowshoe hare, showing the site’s occupants hunted both big and small game during their stays.
Robertson and his crew are contractors with the Center for Environmental Management of Military Lands from Colorado State University. CEMML manages lands with environmental and cultural importance for U.S. Army Garrison Alaska and various other military installations nationwide.
He said the site was identified in 2002 as part of an environmental survey done when the Army was looking for construction sites for the complex. In 2006, when the location was selected, Robertson drew the task of “mitigating” the site.
“When we first came out here, all these trees were still standing,” he said as he pointed to acres of open land, recently denuded of stands of aspen and spruce. “It took us about 45 minutes to get to the site. It’s dried out considerably, but that was a very boggy area.
“During the course of our investigations, we found the site was actually four times larger than we originally thought, and we started finding a lot of these artifacts that made it a unique site — a site that needed a lot more attention,” he continued. “That led to this field season and hiring more people. Last year we had 12 people, this year we have a staff of 20, with 18 on site at any given time.”
Potential sites are found by sleuth work combined with field work, Robertson said. Sites are found by looking at the terrain and then digging lots of test holes.
“Primarily you would look for places close to water,” he said as he pointed to a small pond near the site. “Then you would dig lots of holes around the margins of the lake and at every high point around the lake.”
He said while some sites are found in unlikely places, the majority are found in “high probability” areas.
“People’s needs then were the same as they are now — you need water, you need shelter, you need food,” he explained. “There’s plenty of food available here, there’s water right at hand and we’re finding where they made their shelter.”
Among Robertson’s crew is an archaeologist who helped initially identify the site in 2002.
“Of course then, this was all black spruce and you couldn’t really see the land form at all, so we just sort of started doing a transect and we came to a rise right here, which is an indication there could be some archaeology involved,” explained Dave Cory as he labeled a recent find. “We went up on the top of it and we found some artifacts, some flakes and a scraper that were found right on the surface, and so we recorded a site here.”
For Cory, archaeology was a second career after helping build the trans-Alaska oil pipeline.
“I’ve always been interested in ancient history and pre-history and I just enjoy the exploration and the mystery of it all,” he said.
Robertson said pipeline construction was one of the initiating factors for a recent boom in Interior archaeology.
“The field of Alaskan archaeology is relatively young as compared to archaeology elsewhere in the world,” he explained. “They were doing archaeology in Egypt and Meso-America in the 1700s and 1800s.
“Archaeology didn’t really start in the lower 48 until the turn of the century, the 1900s and (1920s), and they had a lot more time to work out the chronology of how things happened,” he continued. “Archaeology in Alaska didn’t start until the 50s, and it really took off in the 60s and 70s, especially with development and the pipeline coming through the Interior. That led to a whole birth of Alaskan archaeology.
“People didn’t look to the Interior of Alaska until the 60s and 70s, all the early work was on the coast,” Robertson said. “This site will be important because it has a lot of the artifacts that are ‘type artifacts’ for certain components of Alaskan chronology, but we’ll be able to date them.
“Alaskan chronology is not set in stone, it is still at the birth and it will go through several changes within my lifetime.”
Charles Holmes, an affiliate assistant professor in the anthropology department of the University of Alaska Anchorage, recently visited the site and said there are several reasons the site is important.
“First, the site is buried so it is possible to discover if more than one occupation episode is represented, and possibly obtain radiocarbon dates on charcoal from ancient campfires,” Holmes said. “Aaron (Robertson) showed us the stratigraphy in the excavation pits and where concentrations of artifacts were recovered. The careful excavation and recording of the artifacts will help the archaeologists find horizontal patterns of activity across the site and possibly vertical patterns through time.
“Second, the site is large by interior Alaska standards,” he continued. “There was lots of room for ancient people to camp and conduct various activities, such as stone tool manufacture and maintenance, animal hide processing and food preparation. Thus, different areas of the site could be investigated and compared.
“Third, diagnostic stone tools have been recovered that show the site was occupied by different groups at different periods over thousands of years,” Holmes explained. “Distinctive projectile points suggest the early hunters may have lived at the site around 12,000 years ago. Other tools, such as scrapers and burins indicate various activities like hide scraping and antler or bone working were conducted at the site.”
Holmes had praise for Robertson’s work at the site, and the Army’s conviction to allow excavation before construction work destroyed the find.
“Aaron and his team have done a great job of locating and inventorying archaeological resources at (the site),” said Holmes, who describes himself as a semi-retired freelance archaeologist who does consulting and contract work. He also continues to do archaeological research in the Tanana Valley. “It is fortunate that this important site was discovered and evaluated for significance before construction activities began.
“The team discovered that the site is bigger than first thought and has been able to recover more data than was anticipated,” Holmes continued. “The Army was able to extend the time for the archaeologists to work by at least a month. I only wish that Aaron and his team would have been able to excavate more of the site.”
“We’re ultimately responsible for the 1.5 million acres of land entrusted to our use. So it’s very important that we all work together to preserve Alaska’s heritage,” said Col. Dave Shutt, USAG Alaska commander. “We’re proud of the fact we made such a positive impact by excavating the Battle Area Complex site before construction began.”
Holmes and Robertson both noted archaeological data recovery is only one step in preservation.
“All of the data will have to be organized, catalogued and analyzed,” Holmes explained. “Then a comprehensive report of the analysis, which explains the data and puts the information in context, will have to be prepared.
“I think Aaron has made a good start on these tasks. In the end, the Army will have made a significant contribution to our knowledge of Interior Alaska archaeology.”
High-resolution
photos are available. If you’d like more information, please contact Bob Hall, the U.S. Army Garrison-Alaska Public Affairs Officer, at (907) 384-2546 or (907) 748-7459.