The Castro de Vila Nova de São Pedro (VNSP) is an emblematic settlement located at Azambuja, Portugal. It was predominantly occupied during the Chalcolithic period (III Millennium BC). A diversified collection of 53 copper-based artefacts (mostly in a fragmentary condition), belonging to the extensive metallic collection of VNSP deposited at MAC, was studied using micro-EDXRF spectrometry, optical microscopy, SEM-EDS and Vickers microhardness measurements. Results show that the artefacts collection is mainly composed of copper or arsenical copper, being 38% made of copper alloyed with arsenic (As > 2%). A statistically significant association was found between copper alloyed with arsenic and artefacts classified as tools/weapons (blades, arrowheads and daggers). Microstructural analyses show that the majority of this group (73%) was shaped with forging plus annealing operation cycles and 23% received a final cold hammering. An association between the presence of a final forging treatment and artefacts presenting higher arsenic contents was identified. Nevertheless, no direct correlation was found between the arsenic content of the alloy and/or a final forging treatment and artefacts hardness. However, it was observed that a harder forging was applied to the cutting edge of the artefacts and despite the arsenic content in the alloy a high hardness was obtained in this area.
|Journal||Estudos Arqueológicos de Oeiras|
|Publication status||Published - 1 Jan 2012|