Characteristics of Ore Protolith in Bronze Age Metallurgy of Steppe Cis-Urals

Abstract

The paper addresses the issues of determining the probable sources of copper raw materials in the Bronze Age metal production of the 4th–2nd Millennia BC in the territory of the steppe Cis-Urals. The author summarized and systematized the data of field, experimental and geochemical analytical studies of 2016–2021. A relationship was established between the original ore protolith of Bronze Age metallurgy with predominant sulfide materials of cuprous shales and sandstones of the late Permian period with an initial copper content of 17–25%. Bronze Age quarries and mines were cut into sulfide ore lens on the watercourses of fossil temporary streams of the late Permian period. In terms of mineralogy, the sulfide protolith was based on chalcosine in association with covellite, bornite, and to a lesser extent chalcopyrite, pyrite, chrysocolla, etc. Processing sites with burn pits and sludge dumps were located in the vicinity of the Bronze Age mines, which served for pyrotechnic concentrating and refining of lumpy sulfide ore and their processing into a metallurgical concentrate – pyrolite – with an average copper content of 35–45%, and sulfur content of 7–10%. The major portion of carbonate ore materials (azurmalachite) with a relatively low copper content of 1.5–2.5% was unused in antiquity. All mines of this type of ores in the Urals date back to the Modern period.

Keywords

• archaeology
• bronze age
• copper mines
• raw material base
• ore protolith
• secondary sulfides in cuprous shales and sandstones
• metal production
• steppe cis-urals