Portugal’s mining strategy may favour copper over lithium
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Three lead ingots dating from the Roman era and discovered at the Los Escoriales de Doña Rama deposit in southern Spain, demonstrate the importance of lead production and export in the province of Córdoba, according to recent research.
Measuring some 45 centimetres long and weighing between 24 and 32 kilos, the ingots are triangular, resembling a Toblerone bar.
There are only three of them and one is broken in half but recent analyses of these artifacts yield enough information to state that ancient Córdoba was the western ancient world’s main center for lead smelting. Back then, the metal was used to produce a multitude of everyday tools, such as spoons, tiles, and pipes.
Ancient Córdoba was the capital of the Roman Empire’s region of Baetica, whose territory occupied what is today the north of the province, encompassing the Guadiato Valley, Los Pedroches, and some districts of Jaen, Ciudad Real and Badajoz.
The ingots, dating from the first century A.D., were unearthed in the twentieth century during work on the Maghreb-Europe gas pipeline and were kept in the Belmez Museum and private homes. Two of them bear an identifying mark, making it possible to reveal part of their history and to confirm the great importance of mining in the central Sierra Morena area during the Roman period.
This mark is actually two letters, “S S,” referring to the Societas Sisaponensis, a mining company likely headquartered in Córdoba but originally founded in La Bienvenida, a town in Almodóvar del Campo, Ciudad Real, which was famous for the production of cinnabar.
In addition to the ingots’ triangular shape, which optimizes their storage capacity, the fact that they bore these letters means that they were supposed to be exported. The mark identifies the producer of the pieces, which were to be loaded onto ships along with other products.
Thus, the industrial activity in northern Córdoba was not limited to the production of lead and silver, something that has been known for a while, but also involved exports, placing the area among the main producers of metals intended for Mediterranean trade.
Analysis of the ingots’ chemical composition and stable isotopes allowed the research team to verify that they were desilvered and that the ore with which they were made was from the district of Fuente Obejuna-Azuaga, a major mining area that included the Doña Rama site where the ingots were found. In other words, the three pieces had a common origin linked to the same site where they were discovered.
The fact that the ingots were found in the same area where they were produced is exceptional, and the reason for this is unknown. Most ingots of this type have been found at the bottom of the Mediterranean Sea, at shipwreck sites, and it is precisely at the bottom of the sea where the most information has been obtained.
“This information demonstrates that, in antiquity, these northern regions of Córdoba boasted major metallurgical networks of great commercial and economic importance in the Mediterranean,” said University of Córdoba researcher Antonio Monterroso Checa. “This reveals the level of industrialization, skill and knowledge necessary to reach that level of manufacturing.”
Although much remains to be studied, the Doña Rama site would seem to be a mining town complete with a foundry, a processing area and, possibly, a fortress. “But all this remains to be studied,” Monterroso Checa said.
