Forms of occurrence and micro-nano ensambles of gold as indicators of formation conditions, spatial distribution, and type of orogenic deposits in Uzbekistan (South Tien Shan)

Gold ore deposits of Uzbekistan are confined to the South Tien Shan orogenic belt. They are located in black shales (Muruntau, Amantaytau, Daugyztau), terrigenous sedimentary (Kokpatas), volcanic (Balpantau), and intrusive (Zarmitan, Guzhumsai) rocks. Their age is 280—290 Ma and coincides with the age of post-collision granitoid magmatism. The deposits form Kyzylkum and Nurata mining districts. Gold forms micro-nanoparticles and is incorporated into diversified compounds with Bi, Sb, As, Te, Se, S, Ag, Hg in primary quartz-sulfide and sulfide ores. Seven mineral and geochemical types of ores are recognized: Au—W with scheelite and molybdenite; Au—Bi—Te with maldonite, tellurides, bismuth sulpho-tellurides; Au—As with pyrite, arsenopyrite, Ni—Co minerals; Au—Ag—Te with calaverite, petzite, hessite, etc.; Au—Ag—Se with fichesserite, acanthite, freibergite, agvilarite, petrovskite, etc.; Au—Sb—Ag with aurostibite, boulangerite, burnonite, cincenite, chalcostibite, tetrahedrite, etc.; Au—Hg with cinnabar, consbergite, Hg-bearing native gold. Recoverable resources are determined by 2—3 types of ores. Three main types of gold deposits are proposed on the base of outlined mineralogical and geochemical types: Au—W—Bi—Te (Muruntau, Myutenbay, Zarmitan); Au—As—Sb—Ag (Amantaytau, Kokpatas, Daugyztau); Au—Ag—Sb—Se (Kosmanachi, Okzhetpes). The emphasis on the nanomineral approach in the study of gold, its compounds, and micro-nano ensembles increases the efficiency of searching, typifying and evaluating the prospects of hidden mineralization, and is favorable to determine the conditions of formation and technological properties of gold ores.