Lead pollution reveals the ancient history of Naples
Almost two thousand years after the eruption of Vesuvius that destroyed Pompeii and Herculaneum, certain periods of the history of Naples have just been reconstructed. Until now, historians and archaeologists had wondered about the impact of this volcanic eruption on the Aqua Augusta aqueduct which supplied Naples and neighboring cities with water. Recent geochemical analyses have made it possible to directly link the lead in the water pipes of the period with that trapped in the sediments of the old port of Naples. Results clearly show that the hydraulic network had been destroyed by the eruption of Vesuvius in AD 79 and that it took around fifteen years to replace it.
published in the journal PNAS by the laboratory Archeorient -- environnements et societes de l'Orient ancien (CNRS/Universite Lumiere Lyon 2) and Laboratoire de geologie de Lyon: Terre, planetes et environnement (CNRS/ENS Lyon/Universite Claude Bernard Lyon 1), in collaboration with University of Glasgow, University of Southampton and Universita' degli Studi di Napoli Federico II.
During the construction of a new underground line, archaeological excavations were carried out in the ancient, long-buried port of Naples. They made it possible to study a six-meter thick deposit of sediment layers accumulated in the port over centuries.
|The archaeological excavation site in the ancient port of Naples is opposite|
the town square and a few meters below the present sea level
[Credit: © Hugo Delile]
The analyses mainly revealed two distinct lead isotopes, before and after the eruption of Vesuvius in 79 AD. They prove that the vast water supply system of the bay of Naples was destroyed by the volcanic eruption and reconstructed using lead from one or more different mining areas. This sudden change in the lead signal, which occurred about fifteen years after the eruption, suggests that the Romans repaired the aqueduct and water pipes over a relatively short period of time.
|An example of a stratigraphic section sampled as part of the study. |
It is made up of muddy port sediments whose lead isotope
compositions reveal the Roman history of the town
[Credit: © Hugo Delile]
This interpretation of metal pollution in ancient port sediments, which makes it possible to retrace the history of a region, could be applied to other civilizations and geographical areas. In ongoing debates about the Anthropocene, this approach could provide new perspectives on the dynamics of human footprint on the environment.
Source: CNRS [May 16, 2016]