Shiny bronze in glassy matter: an inconspicuous piece of slag from the Bronze Age mining site of Mušiston (Tajikistan) and its significance for the development of tin metallurgy in Central Asia (original) (raw)

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, 2023

The Bronze Age in Central Asia was dominated by the Andronovo Culture and the Bactria-Margiana Archaeological Complex (BMAC). Both cultural entities produced bronze, however, the extent of bronze production and use varied considerably in space and time across their territories. The introduction and spread of bronze metallurgy in the region is commonly associated with the Andronovo Culture, but comparatively little is known about the copper and tin sources that were exploited to make the bronze. To shed light on this aspect, this paper examines 91 bronze artefacts from the Middle Bronze Age (MBA) and the Late Bronze Age (LBA) recovered from twenty sites of Andronovo and the BMAC through a combined evaluation of chemical and isotopic analyses. Trace element patterns and isotopic compositions of lead, tin, and copper are determined for the objects complemented by tin isotope analysis of Central Asian tin ores. The data shows a clear separation of two source areas in the MBA and LBA I: the BMAC obtained copper from polymetallic (tin-bearing) deposits in Iran (Deh Hosein, Nakhlak/Bagh Gorogh) and possibly Afghanistan, while the Andronovo Culture mainly used copper from the Tian Shan Mountains. With the transition to the LBA II, a change in the material basis can be recognised, in which the BMAC increasingly relied on metal deposits from the Andronovo territory. The most important result in this context is the analytical proof of the coextraction of copper and tin from the copper-tin mine at Mushiston, Tajikistan, and the first direct link of tin in bronze objects with a tin deposit. Mushiston apparently supplied both cultural macro regions with a “natural” bronze, which accounted for about one third of all objects analysed, but there is no indication yet that metal or ores from Mushiston were traded or used at a distance of more than 500 km. Moreover, the artefact data indicates a decline in the exploitation of the mine in the course of the developed LBA, while other copper and tin sources in the Tian Shan and probably the Hindukush were exploited. This testifies to the intensive use of the rich mineral resources of Central Asia and beyond, as well as the intensification of cultural and trade contacts between Andronovo and the BMAC.

The Bronze Metallurgy in the Iron Age Tin Bronze Production Tradition during the Iron Age in the Central Zagros, by Omid Oudbashi

2019

The development of metallurgy of tin Bronze in the Luristan region during the prehistoric period has been a subject of interest for archaeologists and scientists. Tin Bronze was firstly used at the early Bronze Age (begin-ning of the third millennium BC) in western Iran and was widespread during the Iron Age (end of second millennium and first half of the first millennium BC) at the Luristan region , well-known as the Luristan Bronzes. Nevertheless, there are only some scientific and analytical studies about the metallurgy of tin Bronze in Luristan during the Iron Age, despite of large number of Bronze objects discovered from looting as well as archaeological excavations. In this paper, a comparative and statistical study is undertaken on the available analytical results of some Bronze objects from Luristan. These are including the un-provenanced collections in museums as well as objects excavated from some Iron Age sites such as War Kabud, Bard-i Bal, Sangtarashan, Baba Jilan and so on. The results show that the majority of Luristan Bronzes are made of the variable tin-containing binary Bronze alloy, although arsenic and lead have important role in the composition of some objects. Based on the chemical compsoiton of objects, it is worth noting that there is no correlation between objects’ typology and alloy composition in the Luristan Bronzes. The probable methods applied to produce tin Bronze may be an uncontrolled alloying operation such as cementation, co-smelting or using Cu-Sn complex ores directly

Copper smelting technology at 2nd millennium BC Taldysai (Kazakhstan) and its place in the wider Eurasian metalmaking framework

Journal of Archaeological Science: Reports, 2023

The 2nd millennium BC in the Eurasian Steppe has widely been recognised as the period of exponential surge in circulation of metals, as well as metal exploitation activities across this area. Nevertheless, there is a general paucity of data on metal production in the steppes, which comes in as crucial in the interpretation of the role metalmaking played in the Bronze Age Eurasian Steppe communities. Here we report analyses of a pilot sample of nine smelting slags from the 2nd millennium BC metalmaking workshop of Taldysai in Central Kazakhstan. Our preliminary results identified at least two metal production lines: copper and arsenical copper. Copper metal was obtained by co-smelting copper oxides and sulfides most likely originating from local cuprous sandstone in a single step. Arsenical copper production is exhibited through co-smelting of copper and arsenic-rich ores in two steps, one to remove sulfur, the second to release the iron present in the charge. Compared against a reference database of nine 2nd millennium BC Bronze Age metal production sites across Eurasia, our results suggest that metalsmiths had mastered multiple ways to extract copper-based alloys: by combining raw materials in different recipes, applying diverse pyrotechnological solutions and exploiting a variety of locally and regionally available ores. This perspective allows for postulating local inventiveness at play for copper and copper alloy production in the Bronze Age steppes, and beyond.

Tainted ores and the rise of tin bronzes in Eurasia, c. 6500 years ago

2013

The earliest tin bronze artefacts in Eurasia are generally believed to have appeared in the Near East in the early third millennium BC. Here we present tin bronze artefacts that occur far from the Near East, and in a significantly earlier period. Excavations at Pločnik, a Vinča culture site in Serbia, recovered a piece of tin bronze foil from an occupation layer dated to the mid fifth millennium BC. The discovery prompted a reassessment of 14 insufficiently contextualised early tin bronze artefacts from the Balkans. They too were found to derive from the smelting of copper-tin ores. These tin bronzes extend the record of bronze making by c. 1500 years, and challenge the conventional narrative of Eurasian metallurgical development.