A massive accounting of ice cores taken from deep inside the ice of Greenland show the boom and bust times of antiquity, especially the rise and fall of Rome, according to a new study.

Lead was sent into the atmosphere through the smelting of silver in Europe, and sent thousands of miles to the desolation of the far north, according to the paper, published Monday in the Proceedings of the National Academy of Sciences.

The lead traces track well-documented history, from the first trading exploits of the Phoenicians, through the disastrous plagues and wars of the Roman Empire– a period spanning some 1900 years.

“Our sub-annually resolved, precisely dated record of estimated European lead emissions provides a much more accurate and detailed history of lead-silver mining and smelting activities during antiquity, and reflects both periods of prosperity and economic disruption,” writes the interdisciplinary team, made up of ice core experts, archaeologists and atmospheric scientists.

Previous work had studied the concept in the 1990s, relying on a series of about 18 measurements. This latest accounting took 21,000, according to the experts.

The team isolated where the most promising samples would be taken, based on an atmospheric transport and deposition model called FLEXPART.

At the location in the middle of Greenland called NGRIP2, they plunged deep into the ice sheet– the samples were collected beginning in 1998, and extend from 159.56 meters below the surface to 582.43 meters.

The analysis was conducted using two Element2, high-resolution inductively coupled plasma mass spectrometers, according to the paper. The lead isotopes match those by Roman and other civilization distinctive smelting techniques.

The lead levels were cross-referenced with the depth and date of deposition. The narrative showed the first smelting of silver by the Phoenicians around 1000 B.C., and grew ever larger during the mining in Iberia by both the Romans and Carthaginians in the 4th to 2nd centuries B.C., the authors write.

The peak was reached by the time of the Pax Romana, the 1st and 2nd centuries A.D., and the largest flowering of the Roman Empire throughout the Mediterranean, according to the study authors. 

But the downturns throughout the timeline show crises of different kinds. For instance, the lead signals drop off significantly during the Punic Wars– the massive wars between Rome and Carthage the former ultimately won. The final decades of the Roman Republic, a time of turmoil, also showed less economic activity, according to the findings.

The smelting dropped off for good with the advent of the Antonine Plague of the 2nd century A.D., and the Plague of Cyprian in the following century. These disastrous pandemics, which are estimated to have claimed millions of lives, likely brought Roman commerce to a near-standstill, the scientists write.

“The Antonine Plague emerges as an abrupt transition, marking the end of high lead emissions in Europe and ushering in a period of much lower lead-silver production lasting more than five centuries,” write the scientists. “Unlike the recently reported response to the 14th century Black Death pandemic, the nearly immediate and persistent emissions declines following major plague outbreaks suggest low societal resilience and far-reaching economic effects.”

Isotopes have also been used to documente the fortunes of Rome– from within the coins traded in the Empire itself, as documented in a paper published last summer.