A record of ancient Rome’s economy turns up in a glacier in Greenland

By THE DATA TEAM

SILVER mining in antiquity was a dreadfully unpleasant business. Galena, a silver-bearing lead ore mined in Europe, mostly in Iberia, was crushed and heated for hours to yield its silver. The process was nasty but necessary: silver was the main coin of the Mediterranean region, and especially the Roman world. Romans (or, rather, their slaves) worked the mines on an unprecedented scale.

While this silver was crossing palms across Europe, lead fumes from the smelting rose into atmospheric currents that carried them over Greenland, where they settled onto glaciers and were trapped in the ice. This is where climate researchers found them.

Not all the lead trapped in the glacier comes from silver mining, but much of it does. Based on these lead levels, researchers can make an educated guess about the intensity of silver production in western Europe.

Sources from antiquity are full of stories of politics, intrigue, and war, but often sparse on the details of everyday life—much less national accounts. And while Rome’s history is well-documented, that of Carthage and Phoenicia is virtually unknown. These data provide a new window onto the workings of the ancient economy. Few historians would have gone to Greenland to look for insight into the Mediterranean world. But it turns out it was there all along.