New analyses of isotopes of ancient copper ingots have disclosed secrets of the surprising range of early Iron Age trade routes and how Mediterranean peoples of that time sourced metals from many areas to create their tools.
The ingots, which were lost in a shipwreck that occurred approximately 2,600 years ago, were found at Rochelongue, near Cap D’Agde in the Languedoc region of France, just west of Marseille — which was itself a Greek colony originally.
The divers who first uncovered them in 1964 had no way of knowing that at some point in the future there would be a way of determining exactly where all the metals that went into their creation originated from.
Iron Age trade in metals surprisingly large, sophisticated
But now, thanks to isotope research, a team of researchers from Flinders University has shown that the metals came from a range of Mediterranean nations.
Working with researchers from the Institute of History (CSIC) in Spain, they determined that the metals came from that country as well as Alpine countries.
Flinders University Maritime Archaeology Associate Professor Wendy van Duivenvoorde says “These metallic objects are important diagnostically, because they lend themselves to source tracing of geological components, and technological studies of their processing and manufacture.”
“The copper ingots were made of unalloyed copper with low levels of impurities – and more than half can be linked to the Iberian Peninsula,” she notes, adding “This points to the circulation of metal through the wider Mediterranean region, but also to local and western alpine mining and manufacture, and possibly north-western Sardinia. Therefore, the Rochelongue items speak of indigenous agency rather than maritime intervention.”
The researchers state that trading in metals, especially with seafaring peoples from the Levant, the Aegean and the Greek mainland, influenced the development of the indigenous communities in that part of the Mediterranean by introducing their material culture and traditions.
The shipwreck, which historians believe involved a total of four boats, occurred west of Cap d’Agde in southwestern France. Dating back to approximately 600 BC, the ships’ cargoes included an incredible 800 kg (1,763 pounds) of copper ingots and approximately 1,700 bronze artifacts.
These objects contain highly-refined copper with just traces of lead, antimony, nickel and silver, the researchers state.
Flinders University maritime archaeologist Dr. Enrique Aragón Nunez says the new isotope analysis shows the composition of the ingots shows they have Iberian and also eastern Alpine metalliferous sources, as well as — possibly — some Mediterranean sources.
This demonstrates, he says, that maritime trading routes were established in this period between the Atlantic, Continental and Mediterranean regions.
As reported in archaeology.it, this discovery now provides a way to investigate the maritime connections and cultural interactions between France’s Languedoc area and the broader Western Mediterranean basin in 600 BC; this even predates the permanent Greek settlement that was founded in what is now Marseille (as Massala).
While the different sizes, shapes and compositions of the ingots found at Rochelongue indicate they originated from a range of geographical sources, the elemental and lead isotope analyses provide a much more comprehensive knowledge, the researchers say.
They state that these show a wide-ranging Iron Age trade network existed in this era for metals, including both continental and maritime routes.
All the mass spectrometry investigations on the copper ingots was performed at SGlker Lab at the University of the Basque Country (UPV) in Bilbao, Spain.
The scientific findings have been published in the Journal of Archaeological Science.