Newswise — Russian scientists together with colleagues from Kazakhstan analyzed artefacts of Late Bronze Age, found in Ural-Kazakhstan region. Authors tested the hypothesis that people living about 1500 years BCE, already had mined iron ore. It turned out that alloys of iron in most findings were natural ones. The only place in the region where miners had mined iron ore in II millennium BC is settlement Kent in the Central Kazakhstan. The research is published in journal “Vestnik Arheologii, Antropologii i Etnografii”.
People began to pass from copper instruments to iron ones about 3 thousand years ago. Each region has its own precise date of this technological innovation, however as far as Ural-Kazakhstan region is concerned you need some clarification – there are few archeological evidences that could help to fix the beginning of the Iron Age. On order to begin to use other metal, people had to invent absolutely new methods of processing of raw material. In Ural-Kazakhstan region up to date there are almost no evidences of beginning of these difficult and laborious processes.
To tell about how it happened can archeological artefacts of the region. Ural and Central Kazakhstan are large centers of metallurgy of the Late Bronze Age (II millennium BC). Here there are a lot of deposits of iron and copper. But findings of metallurgical products of that time don’t have the direct dating, concrete date or diapason. Another mystery is things from iron-copper alloys, found in the Ural-Kazakhstan region, - archeologists don’t know how they appeared. They might be the first attempts of metal production, or maybe previous technologies of copper and bronze metallurgy.
Scientists from Russia and Kazakhstan decided to find out how iron-containing artefacts appeared in Ural-Kazakhstan region in the Final Bronze Age. In order to do this, authors studied 13 products from 9 settlements: three copper products (knife and two metal badges), one iron-copper ingot and nine samples of by-products of melting – metallurgical slags.
Archeologists gathered samples, made cuts and placed them into epoxy resin. With the help of electronic microscopy, they defined the composition of products. Almost all they were made from copper and iron: for example, there were alloys of iron in quantity of 2,25-2,27% in the knife from settlement Chebarkul III. The product also had mineral inclusions of sulphide ores.
Artefacts from other settlements were not characterized by a unique composition. Microinclusions of iron often met in form of small metal drops: for example, one of such drops researchers found in metal slag from settlement Ishkinovka. In this drop remained as iron with copper and also relics of sulphides – chalcocite and bornite.
Most of all scientists were interested in two samples of metallurgical slag from settlement Kent in Central Kazakhstan. Slags had uneven structure: some parts were rich in iron, and some didn’t have metal at all. Clean composition of iron in a slag speaks of the fact that metal couldn’t restore from copper ore accidentally. Ancient metallurgists obtained it purposely from iron ores, however scientists haven’t fixed its deposit yet. Ancient people might use mine at Kentobe or nearby.
Archeologists came to conclusion that high content of iron in copper was a peculiarity of copper ore, that was used by ancient people, and not deliberate technology of addition of iron minerals. Metallurgists mined copper ore from deposits, rich in iron-rich minerals. The only artefacts that prove direct smelting of metal from iron ore – fragments of slags from settlement of Kent. However, their quantity is so small that it is impossible to speak about iron industry in that time.
In the Final Bronze Age iron practically wasn’t used and outgrew into a separate branch of metallurgy only by half of I millennium BC. Researchers doubted the hypothesis that iron melting was discovered on the base of nonferrous metallurgy. Most likely iron industry developed thanks to miners’ experiment with ores of iron deposits – such as was conducted by Kent’s metallurgists.
In research participated scientists from South Ural Federal Research Centre of Mineralogy and Geoecology of Ural Branch of RAS, Institute of History and Archeology of Ural branch of RAS, South Ural state humanitarian pedagogical university, Karaganda Buketov University and Chelyabinsk State University.
The material is prepared with the financial support of the Russian Ministry of Education and Science within the framework of the federal project "Popularization of science and technology".
RSS