6,000 years of arrows emerge from melting Norwegian ice

Norwegian archaeologists have discovered dozens of spiers – some 6,000 years old – melting on a 60-acre patch of ice in the county’s high mountains.

Expeditions to study the Langfonne pack ice in 2014 and 2016, two particularly hot summers, also revealed copious reindeer bones and antlers, suggesting that hunters have used pack ice for millennia. Their hunting technique has remained the same, although the weapons they used have evolved from stone and river shell arrowheads to iron tips.

Now the research team reveals the findings in an article published today in the journal Holocene. A record-breaking total of 68 full and partial arrows (and five arrowheads) were ultimately discovered by the team on and around the slab of melting ice – more than archaeologists have recovered from any other frozen site in the world. . Some of the projectiles date from the Neolithic period while the most “recent” finds date from the 14th century AD.

While the sheer number of historic projectiles is astounding, Langfonne’s discoveries also overturn generally accepted ideas in the relatively new specialty of ice sheet archeology, and provide new clues to the potential of ice to be preserved or destroyed. evidence of the past over thousands of years.

Since archaeologists began to systematically study sites of melting ice 15 years ago, patches of ice from Norway to North America have produced almost perfectly preserved artifacts from a long time ago. Isolated, individual finds contain information about crafts and ancient hunting traditions.

Langfonne, in fact, was one of the first ice patch sites to be discovered, after a local hiker discovered a 3,300-year-old leather shoe sitting next to the edge of the ice patch in the summer. 2006 and reported it to the archaeologist. Lars Pilø, now a researcher in the Cultural Heritage Department of Innlandet County Council and co-author of the new study.

Since this discovery alerted Pilø to the possibility of artifacts being preserved in patches of mountain ice, researchers in Norway and elsewhere – there are similar sites in the Yukon in Canada, in the Rockies in the United States and in the Alps in Europe – wondered if the distribution of objects on and around the ice could tell them how and when the ice sheet sites were used and how they developed over time.

Unlike glaciers, which are essentially slow frozen rivers, ice patches are fixed deposits of snow and ice that can grow and shrink over time. The researchers speculated that sites like Langfonne look like a sheet of snow at the end of winter: As temperatures rise, the artifacts trapped inside melt in the order they were deposited.

“The idea was that ice cream is like a time machine. Everything that lands there stays there and is protected, ”explains Pilø.

This meant that the oldest objects would be found in the deepest core of the ice slab, in the same way that archaeologists working with artifacts buried in the ground assume that the lower layers of earth contain older artifacts. And since the ice patches were thought to increase steadily with each winter’s snowfall, more recent findings would be closer to the edges of the ice sheet.

If the ice patches froze the artifacts exactly where they were lost, archaeologists theorized that these objects could help reconstruct what people have done there in the past, the size of the ice patches at specific times. of prehistoric times and the rate at which they have grown and shrunk over time.

Langfonne’s arrows seemed to be a way to test the time machine theory.

Arrows and reindeer bones confirmed earlier suspicions that Norway’s high mountain ice patches were hot spots for reindeer hunting: when the cold-loving creatures retreated to the ice to avoid biting insects during the summer months, people followed with bows, arrows and hunting knives.

But after radiocarbon dating all of the arrows and collecting dozens of additional dates from reindeer remains they found on the ice, the researchers realized that at least in Langfonne, the time machine theory does not was unreliable. Researchers expected the oldest artefacts to be trapped in place the day they were lost and preserved, as artefacts buried in ice over the following centuries. But Langfonne’s oldest artefacts, which date back to the Neolithic, were fragmented and heavily weathered, as if they had been churned by ice or exposed to sun and wind for years.

Arrows from later periods, like the 1,500-year-old arrow that used a sharp mussel shell harvested from a river at least 50 miles away, appeared to have been fired yesterday. “It raises the suspicion that something happened inside the ice,” which exposed and refrozen the older objects, says Pilø.

And the arrows didn’t seem to emerge in any particular order, as one would expect if the ice formed perfect layers over time. Spiers separated by thousands of years stood not far from each other along the ice edge. “The idea that you find the oldest evidence when the ice patch is at its smallest – that’s not really true,” says Montana State Parks archaeologist Rachel Reckin, who was not part of the ‘Research Team. “It seems gravity and water are moving artifacts down a lot.”

Co-author Atle Nesje, a glaciologist at the University of Bergen, says that thousands of years ago, hot summers likely exposed older artifacts, which were carried to the edge of the ice sheet by streams of meltwater before freezing again. The weight of the ice pressing down on the lower layers could have caused them to move, taking their frozen contents with them. Or, light wooden arrows could have been blown to the surface by high winds before lodging in rocks or becoming covered in snow. Arrows lost in the snow more recently, meanwhile, could have stayed in place.

Because old arrows can be washed away by meltwater and then refrozen, the place where they were found could be very far from where they originally landed. This meant that the use of dated radiocarbon arrows to map the size of the ice patch in the past was a dead end. “Glaciologists and ice sheet archaeologists were hoping the artifacts could give us some idea of ​​size over time, but they don’t,” Reckin says.

The researchers were pleasantly surprised that Langfonne’s arrows, when dated, could provide useful clues as to how people have used the ice patch over time. During some periods, for example, the team found a lot of reindeer bones but very few arrows. This suggests that people weren’t hunting on the ice; instead, the reindeer were probably killed by the wolverines, which bury their carcasses in the snow to eat them later.

Between 600 and 1300 AD – roughly Viking Age – radiocarbon dating revealed a different type of activity on the Langfonne patch. “There are a lot of arrows found, but almost no reindeer material,” says Pilø. “It is not a coincidence.” Humans worked hard to remove the slain reindeer from the ice, harvesting their fur and antlers to sell as trade goods.

The rapidly evolving understanding of ice and the secrets it holds matches the speed at which ice is disappearing. “I have been studying Norwegian glaciers for 40 years. It’s a lot of change, ”says Nesje. “It’s pretty scary how quickly the ice sheets can melt, from one day to the next.

Based on the growth of lichens on rocks around the pack ice, Nesje estimates that Langfonne is now half its size in the late 1990s – and one-tenth of its extent during the Little Ice Age, a decline centuries of global temperatures that lasted from around 1300 AD into the 1800s.

The constant melting means archaeologists have to move quickly while preserving as much information as possible. “Time is running out and we’re trying to be good scientists while doing our best with the data we have,” Reckin says. “Every piece of this puzzle that helps us understand the complexity of these processes is really helpful.”