A year-by-year economic history of the Roman Empire has been retrieved from the unlikeliest of places: a glacier.

Lead emissions generated by mining operations in Northern Europe reached Greenland and were washed down in snowfall, preserving a record in ice. Emissions rose in periods of peace and prosperity, such as the Pax Romana, which ran from 27 B.C. to A.D. 180, and dropped during the civil wars that preceded the Pax and the rise of the Emperor Augustus. There were also drastic drops that coincided with the Antonine plague of A.D. 165-180, thought to have been smallpox, and the Cyprian plague, cause uncertain, of A.D. 250-270.

Emissions dropped to a low during the Imperial Crisis of A.D. 235-284, when the empire nearly collapsed under the stresses of internal discord, barbarian invasions and the Cyprian plague. The economy recovered a little but entered a final decline signified by the withdrawal of Roman legions from Britain in the early fifth century A.D. and the collapse of the western Roman Empire in A.D. 476.

A coin in a tiny hand meant for ferryman

Biological anthropologist János Balázs and his colleagues think they have solved the mystery of the tiny remains, green and mummified from between the 12th and 16th centuries, and in doing so uncovered a unique form of mummification. They found the baby had copper levels hundreds of times more than average. Balázs discovered a ceramic pot and a copper coin from the dig, leading the team to conclude that someone put the coin into the child’s hand. Many cultures have buried their dead with coins as a way to pay a mythical ferryman to take their souls into the afterlife.

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