PORTUGUESE IRONS OF THE LATE BRONZE. A GEOCHEMICAL VIEW

Abstract

The discovery of iron objects in Portugal, dated from the end of the Bronze Age (12th-11th century BC) in the context of habitats, forces us to reconsider the question of their significance. We present the results of a geo-chemical approach by the comparative analysis of archaeological irons and Portuguese ores. The p-XRF anal-ysis of 15 artifacts from 4 different sites in Beira Interior (Monte do Trigo, Moreirinha and Monte do Frade) and Central (Baiões), indicates that the smelted iron probably derived from two distinct ores. The local typol-ogy and the association of the finds with bronze workshops requires a reexamination as to the question of their origin. The chemical characterization of the irons of Beira Interior, indicates that they are of primitive elaboration given their low quality, while that of Baiões already shows a metallurgical evolution which would be understandable if it were more recent. A comparison with other Bronze Age irons underscores their chem-ical specificity. Local iron rich ores cropping out near Salvador (Penamacor, Beira Interior), were sampled and analyzed by ICP-AES and ICP-MS and compared with various types of iron ores. The composition of Salvador ores compared to that of the Beira Interior artifacts implies a definite consanguinity. The importation of fin-ished objects, such as ingots with local forging must be excluded. The processing of the local ore and its forging by experienced metallurgists but novices in iron metallurgy, is a new and robust explanatory hypothesis in accordance with all the constraints already mentioned. This is the first time that Bronze Age irons can be related to a very likely ore source. The Mediterranean influences, marking the importation of a new and ex-tremely recent know-how, therefore correspond, at least in part, to exchanges from the east and perhaps even to the movement of people. This exotic contribution would be linked to the profound movements in the Med-iterranean context of the 12th century, probably from the Mediterranean East with possibly relays in the cen-tral Mediterranean.