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The Kultuminskoe deposit is located within the Gazimur metallogenic zone in eastern Transbaikalia. Mineralization is associated with the Middle-Upper Jurassic Kultuma pluton composed of subalkaline rock series ranging from quartz monzonites and quartz syenites to granites and of monzodiorite dikes. Dikes of Late Jurassic age are composed of subalkaline gabbro. Analysis of fractionation trends of major and trace elements suggests that the monzonitoids prevailed in the Kultuma pluton and the dike complex formed through the differentiation of subalkaline basaltic melt from an enriched mantle source. The formation of the gold-copper-iron-skarn and mediumtemperature veinlet-disseminated polysulfide and epithermal Ag-Te-Bi mineralization as well as iron-magnesia and silica-alkaline metasomatites was a long multistage process during the general evolution of the ore-magmatic system. [ABSTRACT FROM AUTHOR]

The Noion-Tologoi polymetallic deposit corresponds to the Akatui type of polymetallic deposits of eastern Transbaikalia. These deposits are associated with volcanoplutonic rocks of the Akatui complex. In element contents the polymetallic ores of the Noion-Tologoi deposit are similar to ores of volcanohydrothermal (VHMS type) deposits of southern Siberia. The orebodies are tabular, stockwork- and vein-like. They are localized in fault zones. The ores contain, on the average, 4.9% Pb, 6.8% Zn, and 272 ppm Ag. The most common ore minerals are pyrite, galena, arsenopyrite, and sphalerite. The δ 18 O (SMOW) values in the ore quartz range from -3.9 to + 10.6‰. The isotopic composition of oxygen in the fluid (at 250-275 °C) varies from -12.80 to + 2.79‰, indicating the participation of meteoric waters in mineralization. The enclosing rocks are volcanoterrigenous deposits of the Mulino Group (J 2-3 ) and syenite porphyry of the Akatui complex (J 2-3 ). In geochemical characteristics the syenite porphyry is similar to adakite intrusions. The Rb-Sr isotopic age of syenite porphyry is 150 ± 9 Ma. The initial ratio of strontium isotopes in these rocks is ( 87 Sr/ 86 Sr) 0 = 0.70698 ± 0.0004, which indicates their mantle-crustal source. [ABSTRACT FROM AUTHOR]

This work presents the first results of geochronological study of metasomatic rocks accompanying gold-bearing quartz veins of the Uryakh ore field (UOF). Based on the Rb-Sr and Ar-Ar geochronological data, it is shown that hydrothermal metasomatic processes in the ore field occurred about 280 Ma ago (Early Permian) and they are correlated with the terminal phases of formation of the Angara-Vitim batholith. [ABSTRACT FROM AUTHOR]

It has been established that different ore types from the Mesozoic gold deposits of East Transbaikalia were formed from variously differentiated ore-bearing magmatic chambers at different depths of the upper continental crust. The magmatic chambers, which were sources of gold-quartz-arsenopyrite ores, were most differentiated (Eu/Eu* = 0.29-0.32; Rb/Sr = 0.98-1.40) and shallow-seated (Eu/Sm = 0.08-0.14) in contrast to less differentiated and deeper sources of the gold-quartz and gold-sulfide-quartz ores (Eu/Eu* = 0.53-0.72, Rb/Sr = 0.10-0.54, Eu/Sm = 0.11-0.19). [ABSTRACT FROM AUTHOR]

The article investigates the distribution of rare-earth elements in rocks and ores of the Kruchininskoe apatite-titanomagnetite deposit in 70 kilometer to the northeast of Chita in Transbaikalia, Russia. It states that the apatite-titanomagnetite deposit occurs in the Angashan gabbroid massif in the upper reaches of the Kruchina River. It cites ore-bearing gabbro-pyroxenitic and anorthositic as two complexes of basic rocks involved in the geological structure of the Angashan massif. It notes that rocks of the anorthositic series constitute the southern part of the gabbro-anorthosite massif

The article presents a study which aims to establish the geodynamic environment in the formation of fluid-explosive formations (FEFs) in Eastern Transbaikalian region's gold deposits. It states that the Mesozoic gold deposits in the region are associated with the collision process of the Siberian and the Chinese continents in the Mesozoic era. It mentions the average contents of rare and ore elements in the FEFs of the gold deposits are similar. It established that the high degree of differentiation of explosive material is relative to the barren breccias.