Chemistry of tin bronzes and possible sources of tin in the Urals and Kazakhstan in the Late Bronze Age

Abstract

The article discusses geochemical groups identified according to the results of the LA-ISP-MS analysis of tin bronzes of the Ural-Kazakhstan region of the Late Bronze Age. Based on the statistical analysis of 13 impurity elements of 74 bronze and tin-containing copper products from the sites of the 2nd — early 1st mil BC in the Southern Trans-Urals and Northern Kazakhstan, seven chemically contrasting groups have been identified, which mark various types of tin sources. A significant part of the metal reflects the polymetallic nature of tin deposits, which are probably associated with the structures of Northern and Central Kazakhstan, where tin was mined together with copper ores. The second part of the sample — without a clear correlation of tin with other metals — reflects the cassiterite type of ores. It clearly shows the correlation As-Co-Ni±(Sb, Fe, Au), which is characteristic of the copper deposits of the Urals, indicating the alloying of the Ural copper ores with cassiterite master alloys. Data on tin metallogeny, ore chemistry, types of deposits, and known ancient mines of Northern, Central and Eastern Kazakhstan, which could have been sources of raw materials in the metallurgy of the Late Bronze Age, are presented. The main tin-bearing structures of Kazakhstan are the Kokshetau block in the north, the Kalba-Narym zone in the east, and the Ulytau, Bulattau, Atasu, and Sarysu-Teniz structures in Central Kazakhstan. Greisen, quartz-vein and pegmatite types of primary tin deposits, accompanied by placers, are known here. The ores at the deposits are represented both by pure cassiterite (in association with quartz, wolframite, tourmaline, etc.) and by association with sulphides (chalcopyrite, pyrite, arsenopyrite, galena, bismuthine, etc.) and copper oxide-carbonate ores.

Keywords

• late bronze age
• urals
• kazakhstan
• tin bronze
• tin
• trace elements
• tin deposits