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On the trail of the tin mystery of the Bronze Age

Mannheim scientists succeed in making a spectacular breakthrough with multi-parameter approach.

The origin of tin, which was used to produce bronze not only in the Middle and Late Bronze Age in Central Asia (ca. 2200-1300 BC), but throughout the Bronze Age in the Old World, remains one of the greatest mysteries of prehistoric archaeology. Numerous previous archaeological and analytical studies on bronze and pewter objects have been unable to provide any clear indications of its origin. A team of researchers from the Curt-Engelhorn-Zentrum Archäometrie Mannheim (CEZA) has now succeeded in clearly attributing the tin used in the Bronze Age in Central Asia to the Mushiston deposit.

Under the title “The rise of bronze in Central Asia: New evidence for the origin of Bronze Age tin and copper from multi-analytical research”, the scientists have now reported on their research findings on the origin of tin and copper in bronzes from the Bronze Age in Central Asia in the journal “Frontiers in Earth Science”. The publication was written by Dr Daniel Berger, research associate at CEZA Mannheim, and other co-authors.

The team of lead author Daniel Berger and Ernst Pernicka, Scientific Director of the CEZA, reached a first milestone in their quest for the origin of tin back in 2019. In an archaeometallurgical study, they were able to narrow down possible sources of tin by combining tin and lead isotope analyses and determining trace elements. Analyses of Late Bronze Age tin ingots (1530–1300 BC) from sites in the eastern Mediterranean pointed to European tin deposits, particularly those in Cornwall and Devon in south-west England, based on their isotopic and chemical characteristics.

Combination of methods decisive for research success

Even though the focus at that time was on other sites and other material, the combination of different analysis methods paved the way for the current investigations into the origin of Central Asian tin. New avenues for research and advances in analytical procedures were developed and the CEZA database on ore deposits was expanded until a spectacular breakthrough was achieved this year. For the first time, the Mannheim researchers were able to link a specific tin deposit in the Tajik mountains with the tin in bronze artefacts from the region using a multi-parameter approach.

Distribution map of the investigated Central Asian bronzes and copper and tin deposits. The distribution area of the BMAC is marked in green, that of the Andronovo culture in red. (image credits: D. Berger und C. Frank; Berger et al. 2023)

Central Asia was dominated by two cultural groups in the Middle to Late Bronze Age: the Bactria-Margiana Archaeological Complex (BMAC) in the south and the Andronovo culture in the north. Both groups were in close contact from the 18th c. BC onwards, and both produced metal artefacts that were processed with increasing amounts of tin in the Late Bronze Age. The question that could not be answered unequivocally was the specific source of the tin. Some tin mines were already known from field investigations, including Karnab and Lapas in Uzbekistan and Mushiston in Tajikistan. Archaeological excavations had also proven that these mines had been exploited in the Bronze Age.

Specific fingerprint of the deposit

“Thanks to our multi-parameter analyses, however, we are now able for the first time to clearly trace the bronzes of the Andronovo culture and the later stages of the BMAC back to the tin and copper ores of Mushiston. The isotopic and chemical fingerprint of the deposit is so specific that, in combination with the archaeological information, there is no doubt as to its origin,” says archaeometallurgist Berger. Mushiston is archaeological particularly interesting because the smelted ore from there yields a “natural bronze“. This is impressively demonstrated by a burial slag with bronze residues, which was analysed by the Mannheim team in 2022 and attributed to Muschiston.

View of the Mushiston tin deposit at 3000 m altitude in the Tajik Hissar Mountain range and two bronze blades from a BMAC settlement examined in the study.
(image credits: J. Lutz and M. Teufer; Berger et al. 2023)

In total, the team examined more than 90 artefacts from BMAC and Andronovo sites as well as geological samples from numerous tin ores in Central Asia. As a side effect, this made it possible to determine the origin of the copper for many artefacts: Particularly in the Middle Bronze Age, the BMAC relied on copper from the Deh Hosein mine and deposits in the Anarak region of Iran (more than 2000 km in the West). Most probably they also brought tin from this broader region to Central Asia. From the Late Bronze Age onwards, however, cultural relations changed, with the BMAC people increasingly utilising copper and tin from the Andronovo culture (Tienshan Mountains). “On the one hand, this shows the degree of interaction between two cultural groups, but it also throws open a window on interregional economic patterns” says Munich archaeologist Kai Kaniuth, co-author of the study.

Questions about other raw material sources remain unanswered

However, the fact that the procurement of raw materials for bronze was far more complex for people at that time is illustrated not only by the large number of tin and copper deposits in the region, but also by bronze artefacts whose dates do not match Muschiston. This means that the scientists at CEZA still have plenty of research questions left. But more importantly, the results of the study are significant for tin studies in other regions. Artefacts from different cultural areas can now be compared with the new data, bringing us ever closer to finally solve the “tin riddle”.

Original publication:

Berger, D., Kaniuth, K., Boroffka, N., Brügmann, G., Kraus, S., Lutz, J., Teufer, M., Wittke, A., Pernicka, E., 2023. The rise of bronze in Central Asia: New evidence for the origin of Bronze Age tin and copper from multi-analytical research. Frontiers in Earth Science 11.