This article is the first thermodynamically reasoned ancient metal system assessment intended for use by archaeologists and archaeometallurgists to aid in the interpretation of remelted/recycled copper alloys composed of arsenic and copper, and arsenic, copper, and nickel. These models are meant to fulfill two main purposes: first, to be applied toward the identification of progressive and regressive temporal changes in artifact chemistry that would have occurred due to recycling, and second, to provide thermodynamic insight into why such metal combinations existed in antiquity. Built on well-established thermodynamics, these models were created using a combination of custom-written software and published binary thermodynamic systems data adjusted to within the boundary conditions of 1200°C and 1 atm. Using these parameters, the behavior of each element and their likelihood of loss in the binaries As-Cu, As-Ni, Cu-Ni, and ternary As-Cu-Ni, systems, under assumed ancient furnace conditions, was determined.

The As-Cu-Ni System: A Chemical Thermodynamic Model for Ancient Recycling

A l’âge du Bronze ancien en Europe occidentale, l’augmentation drastique de la production de cuivre est tres peu documentee au niveau des activites minieres et metallurgiques de transformation. Dans ce contexte, le gisement minier et metallurgique de Saint-Veran, Hautes-Alpes constitue un temoin privilegie de la production de masse a la fin du 3e millenaire, puisqu’aux travaux miniers rendant compte d’une exploitation a grande echelle, avec une production de pres de sept tonnes de cuivre par an, plusieurs sites de metallurgie extractive ont pu etre associes. Depuis pres de vingt ans, plusieurs equipes dont celle rassemblant les presents auteurs ont mene ou menent des recherches pour tenter de documenter le site et son activite. L’objectif de cet article est de presenter l’etat de nos connaissances du gisement au jour d’aujourd’hui. Les resultats principaux sont la mise en evidence et la quantification de l’activite de production de masse. De plus, une premiere description de l’organisation de la production a pu etre donnee, ou sont mis en lumiere les phasages entre activite miniere et metallurgiques, ainsi que les techniques metallurgiques innovantes mises en place. Le gisement revele un eclatement tres marque de l’activite metallurgique dans l’espace qui ne laisse pas d’interroger. De meme, la question de la destination de la production reste entierement posee. Par ailleurs, les moteurs d’une telle implantation en territoire de haute montagne ont commence d’etre identifies. Ainsi sont evoques, pour les seuls determinismes naturels, aussi bien la mineralisation particuliere du gisement que l’evolution du climat.

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Vingt ans de recherches à Saint-Véran, Hautes Alpes: état des connaissances de l’activité de production de cuivre à l’âge du Bronze ancien

The prehistoric settlement on the Kiechlberg hilltop is located a few kilometres to the north-east of Innsbruck, in the Tyrolean Inn Valley. Despite its rather isolated location, a multiphase settlement between the fifth and the second millennium bc was confirmed by archaeological investigations in 2007 and 2008. Metallurgical artefacts, such as copper ore fragments, copper slag and raw copper, as well as finished copper and bronze artefacts, are concentrated mainly in Late Copper Age to Middle Bronze Age layers. The chemical compositions of the slag and raw metals confirm Fe—Zn tetrahedrite–tennantite (fahlore) smelting. The ore was most probably imported from the 30–50 km distant copper ore deposits (mainly fahlore) of Schwaz–Brixlegg, in the Lower Inn Valley. The small amount of slag and the presence of slagged and thermally altered ceramic fragments suggest copper production in small-scale workshops. Most probably, sulphide-rich ores were smelted in crucibles in a hearth fire. The process was relatively reducing below the 2Sb + 1.5O2  Sb2O3 reaction (−8.5 log fO2 at 1100°C), producing Sb-rich (>10 wt% Sb in metal) raw copper. Inhomogeneous slag remains containing high amounts of sulphide and metal inclusions suggest a poor separation of the metal, matte (copper sulphide) and silicate/oxide melt during the smelting process.

Mineralogical and petrological investigations of early bronze age copper-smelting remains from the kiechlberg (tyrol, austria)

Evidence of arsenical copper smelting in Bronze Age China: A study of metallurgical slag from the Laoniupo site, central Shaanxi

Towards better reconstruction of smelting temperatures: Methodological review and the case of historical K-rich Cu-slags from the Old Copper Basin, Poland

From the end of Chalcolithic times (end of the 4th millennium BC) up to the end of the Bronze Age (1st millenium BC), copper production increases dramatically in Western Europe. However, due to the scarcity of technology-related archaeological data, the technological background sustaining the transition to mass production modes remains poorly understood. The main archaeological clues concerning metal production stem from the metallurgical waste, namely copper slags. Those complex materials may be a genuine chemical footprint of the process. In particular, it may bring new insights on one main issue of the process reconstruction: the origin of the oxygen in the system. A new analytical methodology based on both mass-balance calculation and quantification of Fe3+ contents in copper slags (Mossbauer spectroscopy, electronic microprobe and Synchrotron μ-XANES at the Fe-K-edge) has been set up. This methodology enables us to distinguish between the solid and gaseous sources of oxygen in a broad range of working conditions, thus yielding new features for the understanding of the first smelting processes dealing with copper sulphides in Western Europe 4000 years ago.

M. Fialin

Papers

The reconstruction of the first copper-smelting processes in Europe during the 4th and the 3rd millennium BC: where does the oxygen come from?