At Las Minillas in southern Spain, archaeologists found 735 grooved stone hammers and charcoal that helps date the mine to a busy stretch of the Bronze Age. The evidence suggests the site was producing copper from about 1300 to 800 or 700 B.C.—and that Iberian copper may have traveled as far as Scandinavia.
Copper was a key ingredient in bronze, the metal used for tools, weapons and ornaments across prehistoric Europe. Although researchers have long known about major mines in places such as Wales and the Austrian Alps, the timing and reach of Iberian mining have been harder to pin down. Southern Spain and Portugal have rich copper deposits, but until now, few Iberian mines had enough reliable dates to show how active they were during the Late Bronze Age.
In a study published in the journal Antiquity, researchers combined excavation records, underground surveys and radiocarbon dating of charcoal from Las Minillas. They added 17 dates, ranging from 1350 to 750 B.C. The team also recovered hundreds of stone tools, including the 735 grooved hammers, along with mining remains and Late Bronze Age pottery. Together, these finds make Las Minillas the largest securely dated Late Bronze Age copper mine excavated in Iberia so far.
The mine was part of a much wider network. Researchers have identified 84 prehistoric mining sites across southern Iberia, from southern Portugal to southeastern Spain, though the full size of the network is not yet clear. To look for signs of long-distance trade, the team compared the chemical makeup and lead-isotope signatures of Iberian ores and mining remains with published measurements from Scandinavian bronze objects. Eleven objects had signatures consistent with copper from Las Minillas. That is evidence of a possible connection, though it does not prove exactly how the metal traveled or who carried it.
The researchers estimate Las Minillas may have produced between 49 and 738 tons of copper. Their more cautious estimate is about 197 tons. For comparison, the Welsh mine of Great Orme is estimated to have produced 202 to 756 tons between 1600 and 1400 B.C., while the much larger Mitterberg district in the Austrian Alps produced about 23,000 tons between roughly 1700 and 1300 or 1200 B.C. These sites worked at different times and on different scales, but the figures help show how Iberian mines could have mattered as older sources changed or declined.
The study's authors suggest southern Iberian mines may have supplied faraway buyers through sea routes along the Atlantic coast. The 11 Scandinavian objects offer a clue that copper from the region reached distant parts of Europe, while the new dates place Las Minillas firmly within the period when such trade may have grown. Further research could reveal how the 84 sites were connected and how much copper they supplied. For now, the mine's hammers, charcoal and matching metal signatures make a strong case that Bronze Age Iberia was part of a wider European trade story.