Early metallurgy in Sardinia: characterizing the evidence from Su Coddu

This paper contextualizes analyses of a collection of metal artifacts and ostensible metallurgical slag from the prehistoric settlement of Su Coddu in south-central Sardinia (ca. 3400–2850 BCE). To characterize the types of metals and associated alloys utilized by the earliest residents of Su Coddu, two pins and an unshaped lump of unknown composition were analyzed using portable XRF spectrometry. In addition to metal artifacts, a large quantity of putative slag was discovered at the site that is consistently cited as the earliest evidence of in situ smelting in prehistoric Sardinia. To reconstruct firing temperatures and characterize mineral phases, four samples of the overfired material were selected for thin section petrography and powder XRD analysis. The results of this study indicate that the two pins were made of copper while the unshaped lump was composed of pure lead, making it the earliest lead-based artifact on Sardinia. XRD and petrographic analyses of the fired “slags” reveal that these samples are unrelated to metallurgical smelting and are likely burnt wall coatings whose mineralogical phases correspond with unfired plasters also recovered from the site. These results in combination contribute towards understanding early metallurgical practices in Sardinia and are relevant in reconstructing the events that have shaped the life history of Su Coddu

Phylogeography of a Land Snail Suggests Trans-Mediterranean Neolithic Transport

Background: Fragmented distribution ranges of species with little active dispersal capacity raise the question about their place of origin and the processes and timing of either range fragmentation or dispersal. The peculiar distribution of the land snail Tudorella sulcata s. str. in Southern France, Sardinia and Algeria is such a challenging case. Methodology: Statistical phylogeographic analyses with mitochondrial COI and nuclear hsp70 haplotypes were used to answer the questions of the species' origin, sequence and timing of dispersal. The origin of the species was on Sardinia. Starting from there, a first expansion to Algeria and then to France took place. Abiotic and zoochorous dispersal could be excluded by considering the species' life style, leaving only anthropogenic translocation as parsimonious explanation. The geographic expansion could be dated to approximately 8,000 years before present with a 95% confidence interval of 10,000 to 3,000 years before present. Conclusions: This period coincides with the Neolithic expansion in the Western Mediterranean, suggesting a role of these settlers as vectors. Our findings thus propose that non-domesticated animals and plants may give hints on the direction and timing of early human expansion routes

Italy: The Archaeology of Palaeoshorelines, Coastal Caves and Seafaring Connections

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Roman bronze artefacts from Thamusida (Morocco): Chemical and phase analyses

Twenty-six objects (1st to the 3rd century AD) found at the archaeological site of Thamusida (Morocco), which is a military settlement between the 1st and the 3rd century AD, have been investigated by means of portable X-ray fluorescence and time of flight-neutron diffraction. The combination of element-sensitive X-ray fluorescence and structure-sensitive neutron diffraction yields, in a totally non-destructive way, the necessary information to discriminate the copper alloy from corrosion and alteration layers. Results allowed dividing the repertory into five groups: (a) unalloyed copper, (b) binary alloys made of Cu and Sn, frequently leaded; (c) unleaded binary alloys made of Cu and Zn; (d) ternary alloys made of Cu, Sn and Zn, both leaded and unleaded; (e) quaternary alloys made of Cu, Sn, Zn and As. The choice of alloy is heterogeneous, mainly depending on availability and costs of raw and/or scrap materials and on technological constraints. Interestingly, the reconstruction obtained for Thamusida could either anticipate the important change in the Roman use of copper alloys generally referred as 'zinc decline', or more likely, indicate that brass never conspicuously entered the local metal-working activities of this military site

Non-invasive chemical and phase analysis of Roman bronze artefacts from Thamusida (Morocco)

A repertory of Roman military bronze equipment (1st- 3rd century AD) found at the archaeological site of Thamusida (Rabat, Morocco) was analysed by non-destructive X-ray fluorescence and time of flight neutron diffraction (T. oF-ND). Most objects are made of leaded alloys, where copper is combined with tin and/or zinc and, in six cases, to arsenic as well. A mixed technology was employed, making a limited use of "pure" semi-finished materials if compared with the large utilization of recycled materials (brass and bronze)