Browsing by Author "Silva, Rui J. C."
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- Compositional and microstructural characterization of grave goods from Anta do Malhão and SoalheironasPublication . Valério, Pedro; Silva, Rui J. C.; Soares, António; Araújo, Maria Fátima; Cardoso, João LuísThe technological features of the grave goods from Anta do Malhão and Soalheironas perfectly fit the metallurgical tradition of communities inhabiting the Southwestern Iberia during a period of transition from the 3rd to the 2nd millennium BC. Arsenical copper alloys began to be used for prestige goods of the 3rd millennium BC, becoming the standard for artefacts of the 2nd millennium BC, thus indicating the growing awareness of MBA metallurgists of the aesthetic and practical value of this silvery alloy.
- Compositional and microstructural characterization of grave goods from Anta do Malhão and Soalheironas: an insight into the diachronic use of arsenical copper from the 3rd to the 2nd Millennium BCPublication . Valério, Pedro; Silva, Rui J. C.; Soares, António; Araújo, Maria Fátima; Cardoso, João Luís
- Compositional and microstructural outlook of grave goods from Anta do Malhão and Soalheironas (Portugal): the diachronic use of arsenical copper in southwestern Iberian PeninsulaPublication . Valério, Pedro; Silva, Rui J. C.; Soares, António; Araújo, Maria Fátima; Cardoso, João LuísAlthough in recent years the prehistoric metallurgy of southwestern Iberian Peninsula has become increasingly well understood, the southernmost region still requires additional research. This work presents the technological study of artefacts from burial contexts located in this area, namely the necropolises of Anta do Malhão and Soalheironas (Algarve region). Typologies of metalwork and pottery ascribe the single inhumation at Anta do Malhão to a late phase of the “Ferradeira Horizon” (last quarter of the 3rd millennium BC), while assigning the necropolis of cists at Soalheironas to an earlier phase of the Middle Bronze Age (1st half of the 2nd millennium BC). The elemental and microstructural composition of artefacts was established by micro-energy dispersive Xray fluorescence spectrometry, optical microscopy and scanning electron microscopy with X-ray microanalysis. Results show artefacts made of arsenical copper alloys (2.01–3.40% As) with very low iron content (< 0.05% Fe). The microstructures display deformed equiaxed grains with annealing twins and slip bands, evidencing cycles of hammering and annealing, followed by a finishing hammering operation. The integration of results in the prehistoric metallurgy of southwestern Iberian Peninsula suggests a shared technological tradition, while a more comprehensive discussion discloses important developments involving the increased production of strainhardened tools and weapons, together with a rising substitution of the copper metal by arsenical copper alloys from the 3rd to the 2nd millennium BC.
- Estudo das evidências de produção metalúrgica no Outeiro Redondo (Sesimbra)Publication . Pereira, Filipa; Furtado, Maria João; Soares, António; Araújo, Maria Fátima; Silva, Rui J. C.; Cardoso, João LuísO Outeiro Redondo (Sesimbra) é um sítio arqueológico importante da Estremadura Portuguesa, predominantemente ocupado durante o Calcolítico Pleno/Final (segunda metade do III Milénio a.C.). Este estudo foca‑se na caracterização elementar e microestrutural de 12 artefactos em liga de cobre e de um fragmento de cadinho provenientes deste sítio, contribuindo assim para o conhecimento da metalurgia primitiva naquela região. A metodologia aplicada consistiu em espectrometria de fluorescência de raios ‑X dispersiva de energias, microscopia óptica, microscopia electrónica de varrimento com microanálise de raios ‑X e microdureza Vickers. O arsénio está presente em todos os fragmentos metálicos, quer como impureza (<2 wt%), quer como elemento de liga (>2 wt%), os quais apresentam constituintes microestruturais característicos de diversos processos termomecânicos. O cadinho mostra evidências de uso em operações metalúrgicas de redução de minérios.
- Metallurgical production evidences in the chalcolithic settlement of Moita da Ladra (Vila Franca de Xira, Portugal)Publication . Cardoso, João Luís; Pereira, Filipa; Silva, Rui J. C.; Soares, António; Araújo, Maria FátimaThe archaeological site of Moita da Ladra is na emblematic settlement located at Vila Franca de Xira (Portugal), occupied predominantly during the second half of the 3rd millennia BC (Chalcolithic period). The presente study focuses on the chemical and microstructural characterization of selected artefacts and metallic nodules (metallurgical remains) found there. Its goal is to contribute to a better comprehension of the primitive copper-based metallurgy on the Portuguese estremadura, where other importante chalcolithic sites are located.
- Metallurgical production from the Chalcolithic settlement of Moita da Ladra, PortugalPublication . Pereira, Filipa; Silva, Rui J. C.; Soares, António; Araújo, Maria Fátima; Cardoso, João LuísThe Chalcolithic site of Moita da Ladra, on the right bank of the River Tagus, near Vila Franca de Xira (Portugal), was mainly settled during the second half of the 3rd millennium BC. The large amount of metal artifacts and metallurgical remains recovered at the site indicates local metallurgical activities. Chemical and microstructural characterization of 62 copper-based artifacts and 8 metallic nodules from the settlement are presented. Micro-EDXRF, optical microscopy, SEM-EDS and Vickers microhardness testing were applied in this research. Elemental determinations show artifacts containing variable amounts of arsenic. Forty-five percent of the artifacts have an arsenic content at impurity level (As < 2 wt.%), while the remaining items range from 2.0 wt.% to 5.4 wt.% As. Microstructural analysis shows that artifacts were shaped by hammering and annealing cycles, being 33% of the artifacts finished by cold working. Metallic nodules were produced by smelting operations, and are chemically consistent with the analysed artifact collection. Results are compared with those obtained by similar researches carried out on important contemporary materials from the same geographical area (Portuguese Estremadura) and other Iberian regions (Southern Portugal and Western Andalusia).