Munigua

Located north of the Guadalquivir Valley, Munigua was a small urban centre of conventus hispalensis and Baetica province. It is situated on a granite hill surrounded by peaks of metamorphic Palaeozoic rocks (slates and quartzites) and other lithologies (limestones, conglomerates and coal). The hill of Munigua was selected in pre-Roman times to setting the habitat that became a Roman city because of its domination over the adjacent landscape and the presence of the Tamohoso River.

The city shows an extensive diachronic sequence. It begins in the IV century B.C. when a small pre-Roman, Turdetan mining settlement developed on the top of the hill. But, it is during the first half of I century B.C. when the first inklings of urban structure are noted. At this time the construction of thermae initiated the presence of public architecture, a sign of urban communities in Roman times. However, the settlement gains the judicial status of municipium and the Ius Latii after Vespasian’s Edict in 74 A.D. It is then, when the city acquires a true urban image: public buildings such as the forum and the terrace sanctuary (inspired in Latium Vetus sanctuaries as those of Praeneste and Tibur) are prevalent, along with the walls that enclosed 3.8 Ha.

The III century A.D. marks an inflection point. Two earthquakes caused structural damage to the city, such as the collapse of the porticus. From this moment occupation becomes less intense. It is clear that urban life changed, and public buildings become progressively abandoned. Some sporadic occupations took place, as we observe some craft installations on top of the ruined wall, or some burials inside house 1 dated during the V century. This intermittent use of space ends in the VIII-IX centuries A.D., when the site is completely abandoned.

It should be emphasized that Munigua is located in the geological unit of Ossa Morena mining district, belonging to the Iberian Massif, and at the edge of the Iberian Pyrite Belt, one of the most important and massive volcanogenic sulphide districts in the world. These polymetallic sulphides have been exploited since Late Prehistory, and recent surveys in the territorium of Munigua have documented different phases of exploitation of mining resources through time. Cu and Fe were the extracted metals in Roman times. They originate from seams with copper ore related to large regional fractures, and skarns with iron in limestone rocks within the external aureole of the granite at Ventas Quemadas. Surveys show that sulphides and copper carbonates were extracted from the second half of the I century B.C. to the beginnings of the second half of the I century A.D. The copper ore was smelted directly on the mine, at least the earliest phases of production. Then, the raw metal in form of copper ingots was transported to the city.

Surveys and stratigraphic sequences, however, show an economic and technological change in the second half of the I century A.D. when copper mining is progressively abandoned and systematic iron mining is documented. This change in production entailed a new chaîne opératoire: initially, the ore, after being transported into the city from mines, was smelted near the urban centre, whereby a bloom rich in ferrous oxide was produced. Later, this bloom was smelted in refining furnaces in order to produce metallic iron. These furnaces constituted a metallurgical district outside the settlement. When the city gained the juridical status of municipium and Flavian urbanistic expansion took place, this metallurgical district stopped working and furnaces were sealed by Flavian constructions.