Prehistoric copper production in the Southern Alps, in the Trentino Orientale region

Prehistoric copper production in the Southern Alps, in the Trentino Orientale region

After the chance discovery of a prehistoric battery of furnaces for copper smelting in Acqua Fredda in 1979, the DBM was invited to undertake joint investigations by the Trentino heritage protection agency. After surveys and excavations between 1984 and 1990, the Volkswagen Foundation approved a three-year project. The findings were documented and analysed within the framework of Jan Cierny’s doctoral thesis.

Our knowledge about the prehistoric smelting sites increased enormously in the course of the project. The number of known sites rose from 85 before the project began, to a further 110 find sites. We documented 116 of these sites and collected a few pieces of slag and – where present – charcoal. Despite intensive searching, it was not possible to locate any prehistoric adits, shafts or traces of extraction. These were probably destroyed by the intense mining activity that took place from the Middle Ages to the 20th century. We selected eight smelting sites for excavations; the most productive was the Acqua Fredda find site with its nine copper smelting furnaces. In the surrounding area we discovered work platforms with bricked edges, containing fireplaces. These were used for washing the ore, and more importantly, reprocessing the slag: a channel lined with wood regulated the water inflow. The granulated slag pile, discovered by drilling, is 110 m long and up to 40 m wide – the largest in the Alps! The quantity of the granulated slag is estimated to be about 1300 t. This data alone enables us to calculate that at least 150 to 200 tonnes of copper were produced in Acqua Fredda. This makes it, at present, the largest complex of its kind in the southern Alps. The excavated materials and the radiocarbon analyses suggest that this and the other find sites date back to the Bronze Age, between 1600 and 800/700 BC.
We know of very few smelting sites from the Early Bronze Age, and none at all from the subsequent Middle Bronze Age (MBA); 95 per cent of the known find sites date back to the Late Bronze Age. There is no obvious explanation for why the local copper ore was not mined and processed during the Middle Bronze Age. In the archaeological finds from the settlements and tombs there is no noticeable decline in bronze objects during this period.
In the Late Bronze Age, the copper produced in the region was not used solely for local production. Some of the typical metal objects of the inner alpine Late Bronze Age Laugen culture, mainly located in South Tyrol and Trentino, can be found in the neighbouring regions. There are no find sites for the subsequent Iron Age. However, bronze objects from this period prove that the demand for copper/bronze is likely to have remained unchanged. In contrast, the number of production sites dropped to virtually zero.
The findings of our investigations into prehistoric copper production in the area of study were as follows: firstly, we were able to document numerous slag sites from the Late Bronze Age; secondly, features found at a smelting site enabled us to gain new knowledge about the operational structure and the work processes of a prehistoric smelter. Scientific analyses supplemented the archaeological findings with new insights into the smelting process.

PhD theses

Prozessrekonstruktionen zur spätbronzezeitlichen Kupferverhüttung in den Südalpen

Completed PhD theses

Jan Cierny
Prähistorische Kupferproduktion in den südlichen Alpen, Region Trentino Orientale

Project manager

Prof. Dr. Gerd Weisgerber



Deutsches Bergbau-Museum Bochum

Deutsche Forschungsgemeinschaft


Franco Marzatico (Castello del Buonconsiglio, Trento)

Renato Perini (Trentiner Denkmalpflege)

Ruhr-Universität Bochum





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  • Cierny, J., Weisgerber, G. & Perini, R.: Ein spätbronzezeitlicher Hüttenplatz in Bedollo/Trentino, in: Lippert, Andreas/Spindler, Konrad (Hrsg.): Festschrift zum 50jährigen Bestehen des Institutes für Ur- und Frühgeschichte der Leopold-Franzens-Universität Innsbruck (= Universitätsforschungen zur prähistorischen Archäologie, Bd. 8), Bonn 1992, 97-105.
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