Shifting networks and mixing metals: Changing metal trade routes to Scandinavia correlate with Neolithic and Bronze Age transformations.

Based on 550 metal analyses, this study sheds decisive light on how the Nordic Bronze Age was founded on metal imports from shifting ore sources associated with altered trade routes. On-and-off presence of copper characterised the Neolithic. At 2100-2000 BC, a continuous rise in the flow of metals to southern Scandinavia begins. First to arrive via the central German Únetician hubs was high-impurity metal from the Austrian Inn Valley and Slovakia; this was complemented by high-tin British metal, enabling early local production of tin bronzes. Increased metal use locally fuelled the leadership competitions visible in the metal-led material culture. The Únetice downfall c.1600 BC resulted for a short period in a raw materials shortage, visible in the reuse of existing stocks, but stimulated direct Nordic access to the Carpathian basin. This new access expedited innovations in metalwork with reliance on chalcopyrite from Slovakia, as well as opening new sources in the eastern Alps, along an eastern route that also conveyed Baltic amber as far as the Aegean. British metal plays a central role during this period. Finally, from c.1500 BC, when British copper imports ceased, the predominance of novel northern Italian copper coincides with the full establishment of the NBA and highlights a western route, connecting the NBA with the southern German Tumulus culture and the first transalpine amber traffic.

On the trail of Scandinavia's early metallurgy: Provenance, transfer and mixing.

The rich and long-lasting Nordic Bronze Age was dependent throughout on incoming flows of copper and tin. The crucial turning point for the development of the NBA can be pinpointed as the second phase of the Late Neolithic (LN II, c. 2000-1700 BC) precisely because the availability and use of metal increased markedly at this time. But the precise provenance of copper reaching Scandinavia in the early second millennium is still unclear and our knowledge about the driving force leading to the establishment of the Bronze Age in southern Scandinavia is fragmentary and incomplete. This study, drawing on a large data set of 210 samples representing almost 50% of all existing metal objects known from this period in Denmark, uses trace element (EDXRF) and isotope analyses (MC-ICP-MS) of copper-based artifacts in combination with substantial typological knowledge to profoundly illuminate the contact directions, networks and routes of the earliest metal supplies. It also presents the first investigation of local recycling or mixing of metals originating from different ore regions. Both continuity and change emerge clearly in the metal-trading networks of the Late Neolithic to the first Bronze Age period. Artifacts in LN II consist mainly of high-impurity copper (so-called fahlore type copper), with the clear exception of British imports. Targeted reuse of foreign artifacts in local production is demonstrated by the presence of British metal in local-style axes. The much smaller range of lead isotope ratios among locally crafted compared to imported artifacts is also likely due to mixing. In the latter half of Nordic LN II (1800-1700 BC), the first signs emerge of a new and distinct type of copper with low impurity levels, which gains enormously in importance later in NBA IA.

Correction: On the trail of Scandinavia's early metallurgy: Provenance, transfer and mixing.

[This corrects the article DOI: 10.1371/journal.pone.0219574.].

Isotope systematics and chemical composition of tin ingots from Mochlos (Crete) and other Late Bronze Age sites in the eastern Mediterranean Sea: An ultimate key to tin provenance?

The origin of the tin used for the production of bronze in the Eurasian Bronze Age is still one of the mysteries in prehistoric archaeology. In the past, numerous studies were carried out on archaeological bronze and tin objects with the aim of determining the sources of tin, but all failed to find suitable fingerprints. In this paper we investigate a set of 27 tin ingots from well-known sites in the eastern Mediterranean Sea (Mochlos, Uluburun, Hishuley Carmel, Kfar Samir south, Haifa) that had been the subject of previous archaeological and archaeometallurgical research. By using a combined approach of tin and lead isotopes together with trace elements it is possible to narrow down the potential sources of tin for the first time. The strongly radiogenic composition of lead in the tin ingots from Israel allows the calculation of a geological model age of the parental tin ores of 291 ± 17 Ma. This theoretical formation age excludes Anatolian, central Asian and Egyptian tin deposits as tin sources since they formed either much earlier or later. On the other hand, European tin deposits of the Variscan orogeny agree well with this time span so that an origin from European deposits is suggested. With the help of the tin isotope composition and the trace elements of the objects it is further possible to exclude many tin resources from the European continent and, considering the current state of knowledge and the available data, to conclude that Cornish tin mines are the most likely suppliers for the 13th-12th centuries tin ingots from Israel. Even though a different provenance seems to be suggested for the tin from Mochlos and Uluburun by the actual data, these findings are of great importance for the archaeological interpretation of the trade routes and the circulation of tin during the Late Bronze Age. They demonstrate that the trade networks between the eastern Mediterranean and some place in the east that are assumed for the first half of the 2nd millennium BCE (as indicated by textual evidence from Kültepe/Kanes and Mari) did not exist in the same way towards the last quarter of the millennium.

Kinship-based social inequality in Bronze Age Europe.

Revealing and understanding the mechanisms behind social inequality in prehistoric societies is a major challenge. By combining genome-wide data, isotopic evidence, and anthropological and archaeological data, we have gone beyond the dominating supraregional approaches in archaeogenetics to shed light on the complexity of social status, inheritance rules, and mobility during the Bronze Age. We applied a deep microregional approach and analyzed genome-wide data of 104 human individuals deriving from farmstead-related cemeteries from the Late Neolithic to the Middle Bronze Age in southern Germany. Our results reveal individual households, lasting several generations, that consisted of a high-status core family and unrelated low-status individuals; a social organization accompanied by patrilocality and female exogamy; and the stability of this system over 700 years.