PGE mineralization in andesite explosive breccias associated with the poperechny iron-manganese deposit (Lesser Khingan, Far East Russia): Whole-rock geochemical, 190Pt-4He isotopic, and mineralogical evidence

Gold in Mineralized Volcanic Systems from the Lesser Khingan Range (Russian Far East): Textural Types, Composition and Possible Origins

“…We present in this paper results of study of gold micro-particles in iron oxide ores and associated volcanic rocks from Poperechnoye, Kostenga and Kaylan iron oxide (with manganese) deposits of the Lesser Khingan Range (LKR) ore province in the Russian Far East. Previous studies established significant role of mafic to felsic volcanism in the formation and evolution of these mineral deposits [59][60][61]. We also discuss possible models for origin and evolution of gold in deep-seated crustal magmatic systems with special emphasis on formation of gold deposits in volcanic environments.…”

“…The accuracy was ±5% for the trace elements with abundances of >20 ppm and ±10% for elements with abundances of <20 ppm. Additional details of analytical methods utilized in this study are reported in [61]. All analytical procedures were carried out at the Khabarovsk Innovative-Analytical Center (KhIAC) of the Kosygin Institute of Tectonics and Geophysics (Khabarovsk, Russian Federation).…”

“…The Poperechnoye, Kostenga and Kaylan deposits, together with more than 30 smaller deposits and showings, are part of an extensive cluster of iron oxide and ironmanganese mineralization within the LKR metallogenic province [62,63]. These deposits and mineral prospects are hosted in Vendian-Cambrian carbonate units of the Bureya-Jiamusi-Khanka composite terrane (Figure 1), which forms the easternmost segment of the Central Asian Orogenic Belt [61,64,65].…”

“…Iron-oxide mineralization at the Poperechnoye deposit is represented by silicic hematite-magnetite ores and associated breccias containing up to 20-35 wt.% of total iron. Feoxide (with manganese) ore is concentrated within narrow (50-70 m) sub-longitudinal zone and can be subdivided into two sub-units: 1) Mn-rich (1 to 10 m thick) and 2) Fe-rich (up to 25 m thick) [61]. Ores are composed of dolomite, Mg-siderite, chlorite, quartz, magnetite, hematite with minor apatite, albite, orthoclase and rare grains of barite, monazite and xenotime.…”

“…Explosive breccia and iron-oxide ore from the Poperechnoye deposit contain high concentrations of platinum-group metals (up to 11.3 ppm) and gold (up to 2.5 ppm) [59], which were interpreted as the result of contamination of fluid-saturated magma by PGEand Au-rich material from the deeper levels of sub-continental lithosphere underlying Bureya-Jiamusi-Khanka terrane [61]. Fe-oxide mineralization along the eastern flank of the Poperechnoye deposit is associated with steeply dipping basaltic bodies (Figure 3a,b), which are replaced by mineralized breccias towards the southern terminus of the Poperechnoye deposit.…”