MINERALOGY OF BARITE-POLYMETALLIC DEPOSITS OF ZMEINOGORSK ORE DISTRICT (RUDNY ALTAI)

Abstract

Relevance of the research is conditioned by a need to understand the formation model of studied ore deposits; this leads to development of scientifically valid prediction and estimation and, hence, expansion of available mineral resources (first of all, copper, lead and zinc ores) while continuous prospecting and exploration at Rudny Altai including deeper and side zones of known deposits. The main aim is to study ore mineral composition with use of advanced analytical techniques, mineral and geochemical features and formation processes of barite-polymetallic ore deposits of Zmeinogorsk district. Research methods are represented by a complex study of barite-polymetallic ores including polarization microscopy, energy dispersive X-ray microanalysis of ores and separate sulfides, inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry. The results. Mineralogical composition of barite-polymetallic ores of Zmeinogorsk district deposits has been studied. It includes about 30 minerals, among which are (in descending order) sulfides, sulfosalts, tellurides, oxides, oxyacid salts, native elements and intermetallics. Ore bodies are represented by complex stockworks, band- and lens-shaped bodies with ores belonging to following types (from bottom to top): pyrite-polymetallic, polymetallic and barite-polymetallic ores. Hydrothermal and metasomatic processes preceded ore formation leading to formation of wallrock non-carbonate metasomatites. It was stated that the third stage of mineral formation (bornite-chalcocite association) was the most productive in terms of own mineral phases of precious metals. According to the results of sulfur isotopic composition study in sulfides there was a heterogeneous source of ore material: initial mantle source was later changed by a crustal source. Isotopic composition of first stage sulfides (δ34S) varies from –0,2 to +1,2 ‰; from –2,3 to –3,7 ‰ in second stage sulfides; from –8,9 to –12,8 ‰ in third stage sulfides.

Keywords

• zmeinogorsk ore district
• barite-polymetalic ores
• stages
• paragenetic assemblage
• ulfur isotopic compositions