Geological structure and conditions of formation of Strizhkovskoe barite-polymetallic deposit (Ore Altai)

Strizhkovskoe barite-polymetallic deposit is a typical medium-low-temperature hydrothermal-metasomatic deposit. It's located within north-west part of Zmeinogorsk-Bystrushinskiy downfold; host rocks are volcano-terrigenous Devonian rocks. Ore bodies are related to sublatitudinal and submeridional faults intercrossing. Wallrock quartz-chlorite-sericite metasomatites formed prior to ores formation. Ore mineralization process began in Middle Devonian. Main ore minerals are sphalerite, galena, and chalcopyrite. Also there are gold and silver occurring as electrum, acanthite; silver is present in fahlores as an isomorphous admixture. Formation of the deposit subdivides into two main stages and five phases; according to obtained results of isotope study of the sulfides, it's possible to conclude that there was a mixed source of ore matter (mantle source replacing with crust source). The temperature of main ore formation stage varied form 230 to 180 degrees. Solutions salinity varied from 9 to 15 % wt of NaCl equiv. According to fluid inclusions study results, the solutions consisted of water and following compounds CO2, NH3, SO2, HCO3

Mineralogy and prospect of noble metals of gold-bearing ore breccias from ore fields of polymetallic deposits of Ore Altai

The object of the present study are the ore-bearing breccias of the worked-out lower-middle Devonian gold-silver barite-polymetallic Zmeinogorsky deposit belonging to the cognominal ore district and the conserved massive sulfide Chekmar deposit belonging to the Leninogorsk ore district. Both ore districts occupy an adjacent position within the northeastern depression zone of the Ore Altai megatrough. A brief structural and geological description of near-fault ore-bearing breccias, which developed within the peripheral parts of the deposits, is given. Analysis of petrographic composition of breccia fragments and their cementing material allowed to define barite-quartzite breccias of the Zmeinogorsky deposit and pyritized adularia-quartz metasomatites formed upon acidic igneous rocks and greenschists of the Chekmar deposit. Results of mineralogical studies with use of raster electron microscope show that there are ore minerals microinclusions in the detrital material and cement of breccias. Barite-quartzite breccias of Zmeinogorsk deposit contain barite, galena, Hg and Sb containing polymineral formations, tetrahedrite-boulangerite, bromargyrite, leucoxene. Microquartzites of these breccias mostly consist of quartz. Chekmar deposit ore breccias detrital material contains pyrite, barite, arsenopyrite, galena, sphalerite, zircon, titanite, leucoxene and REE minerals. Quartzitic compound of these breccias is cryptocrystalline and consists of quartz and adularia with admixtures of sericite and pyrite. Due to results obtained by use of SEM it was stated that barite, sulfides and sulfosalts of breccias contain noticeable amounts of dissipated Au, Pd, Pt, Ir. ICP-MS results confirm that studied ore breccias contain such noble metals as Au, Ag, Pd, Pt. Moreover, noble metals contents in Zmeinogorsk deposit breccias reach industrial standards while noble metals of Chekmar deposit ores can be extracted along with the processing of basic massive sulfide ores. Further study of ore breccias is important as these breccias can be considered as a noble metals containing subformation among polymetallic ores of Ore Altai

Material composition of the basalt-trachyte series of the early Devonian of the Saralin graben-rift

The article clarifies the structural-tectonic position of the Saralin graben. It is determined that, along with the Balyksinsky graben located to the south and the Goryachegorsky volcanic plateau to the north, they are the connecting structural links between the Kuznetsk-Alatau alkaline province and the adjacent Minusinsk trough. In the early Devonian, the alkaline province was formed as a vaulted-block structure (the "shoulder" of the rift), and the Minusinsk deflection as a depression with the dominant volcanism in it. The boundary between these positive and negative structures was the deep Balyksinsko-Saralinsky fault

U-Pb geochronology of subvolcanic and pyroclastic formations of the Zmeinogorsk barite-polymetallic deposit (Rudny Altai)

Schemes of Zmeinogorsk ore field structure made in 1996, 1960 and 1949 have been analyzed. The schemes differ from each other in contents and prospecting trends. This study is based on the 1949 scheme, made on the basis of the results of extensive mining and drilling operations. Based on the analysis of stratigraphy, LA-Q-ICP-MS dating results by U-Pb method, rocks composition, plicative and disjunctive dislocations of sedimentary, volcanic and subvolcanic formations, as well as their relationship, an updated scheme of Zmeinogorsk ore field structure is suggested. It belongs to rhyolite dome-type, which is also charactered to the neighboring Leninogorsk ore distric