The 2023 archaeological excavation campaign at Sa Mitja Lluna ended this week. This Bronze Age copper mine located on Illa d'en Colom is one of the few mining sites of its kind in southern Europe, as the absence of subsequent relevant mining works has allowed for the excellent preservation of the prehistoric mine. Its exceptional nature has made it a
key element in the UNESCO World Heritage candidacy.
This is the seventh campaign that has been carried out since its discovery, under the co-direction of the archaeologists Laura Perelló, Bartomeu Llull and María Calderon (ArqueoUIB group, University of the Balearic Islands) and Mark Hunt (University of Seville). As in previous years, the intervention has been financed by the Consell Insular de Menorca.
All the work carried out to date indicates that we are dealing with a copper mining site that spans the entire Bronze Age (1800-900 BC). Therefore, certain prehistoric
communities in Menorca extracted copper minerals (malachite, azurite, chalcopyrite) from the mine for around 900 years.
The research allows us to reflect on the exploitation strategies of the communities that frequented the mine, and there is no doubt that it was exploited for generations, although not continuously. The researchers think that perhaps it was a temporary work that was adapted to other work in the field at certain times of the year, perhaps conditioned by the meteoromarine conditions or the needs of the community.
Among the archaeological materials recovered,
lithic tools stand out. They range from small mortars used to crush and select the ore, to large miner's mallets used to break up the rock where the ore veins are found. They come in many sizes, depending on the work they were intended for. In the Bronze Age, copper ores were essential for creating metal tools, but it was more important the symbolic value of these objects.
Analyses of provenance and distribution using lead isotopes have made it possible to propose possible relationships between the minerals from the Illa d'en Colom and metals found in Menorcan funerary deposits of similar chronology. But the question does not end here; studies carried out on metal pieces on the other islands of the Balearic archipelago show their relationship with Menorcan minerals. This tells us about the
great movement of objects and people that existed in the Balearic Bronze Age.
From the beginning, researchers saw that the Sa Mitja Lluna copper mine had two distinct working areas. In the northern area there seemed to have been a greater movement of material. Work in this area of the site revealed the existence of a trench excavated in the rock, following a copper vein that ran more or less parallel to the cliff, in a N-S direction. It is not to be ruled out that in future interventions there may be surprises in this area, such as the discovery of shafts or galleries dug by the former miners.
Campaign July 2023
For the last two years, archaeologists have been working on excavating the southern part of the site. Initially, the intervention in this area of the mine was envisaged as a one-off action to assess the potential scientific interest. At present, understanding this sector of the site is a priority, and it is thought that the archaeological information provided will be key to understanding the workings of the mine and, more importantly, the people who frequented this area.
Three peculiarities characterise this southern area:
- Hidden beneath the mine tailings, the researchers documented a trench with similar characteristics to those observed in the north of the site, with the difference that in the north there had been a large movement of materials, whereas in the south this has not been detected until its excavation. This trench was dug by the miners in a west-east direction, following the vein of ore. The actual dimensions of the trench are not yet known, but all indications are that the workings are larger than previously thought.
- In this area of the site, more ceramic remains have been documented than in the north, as well as the remains of fires. Although no hearths or other types of combustion structures have been found, these remains are evidence that other work was carried out at the foot of the mine, such as cooking or storing water, as the types of ceramic pieces seem to indicate.
- In some of the deeper stratigraphic units, lithic tools are more abundant and large miner's mallets are more frequent than in the northern part of the site, in many cases weighing more than 15 kg.
From all this it can be concluded that the dimensions of the mine workings in the southern area may be the same or more noticeable than in the northern area. In addition, there is evidence of pottery remains dumped with the mine tailings, showing evidence of subsistence practices at the foot of the mine.
Bearing in mind that no permanent habitat structures have been found at Illa d'en Colom either, the idea of the
seasonality of the prehistoric work makes even more sense: a small group that moved to this site for a few days would leave practically no archaeological evidence. Until recently, only the results of strictly mining work had been seen, but it seems clear that Sa Mitja Lluna is still full of surprises waiting to be unearthed.