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The aim of this study is to determine the prospects of the region for the identification of new objects. For this purpose, it was necessary to solve the tasks of analyzing and summarizing all available geological data on the Torgai trough and based on this, to make forecast maps and determine the prospects for identifying deposits. Analysis of extensive factual data and outcomes of the sedimentary cover minerals was followed by interpretation of sections at the basic outcrops and wells. All this work resulted in compilation of a new stratigraphic chart of Oligocene-Pliocene deposits of the Torgai trough (Northern Kazakhstan). The paragenetic connection of a number of minerals (placer gold of buried ancient valleys, oolitic brown-iron ores, zircon-rutileilmenite placers, brown coals and lignites) with the deposits was established, their distribution regularities were determined, and their prospects were assessed. This approach allows to plan geological exploration work to search for new mineral deposits. Two structural complexes are distinguished in the section of the Torgai trough: complexly dislocated Precambrian and Paleozoic rocks that form the folded basement; and weakly dislocated Mesozoic and Cenozoic sediments that form the sedimentary cover. Features of the structure of Oligocene-Pliocene sedimentary basins of the Turgai Trough, lithological and facial composition of the strata composing them, and the minerals confined to them allowed to make prediction maps for promising types of minerals on the tectonic basis and to conduct systematics of minerals. [ABSTRACT FROM AUTHOR]

Samples of ore for micromineralogical research were selected from the core of boreholes. The mineral composition of the ores, their textural and structural features were examined under an optical microscope in reflected and transmitted light, scanning electronic microscope (SEM) and energy dispersive X-ray spectrometer (EDS) with microanalyzer. Mineralization by its composition is sulfide. The nature of mineralization is imbedded. Phenocrysts are presented by separate idiomorphic grains of pyrite, aggregate intergrowths of several of its grains. Phenocrysts are formed by separate pentagondodehaedrs of pyrite, intergrowths of its grains and rare chains of grains up to 30.0 mm in length. Besides, in the ore sample there is linneit, millerit, idait and sulfosalts in unessential quantities. Minerals of silver are found as dyscrasite up to 0.08 mm and as polibazit up to 0.03 mm in size. Native gold in the sample was observed in the secretions of foliose-scaly form. The size of scales is approximately 0.01 mm. Telluride gold is presented by highly reflective double telluride differences of massive structure - krennerite, calaverite and petzite. Gold form independent isolations, aggregates with each other and intergrowths of gold tellurides with tetradymite. There are sulfides among which pyrite sharply predominates, in a smaller amount inclusions of galena and sphalerite. Along the edges of sphalerite selections pyritechalcopyrite aggregates are observed. Gold is met in the form of fine secretions intergrown with chalcopyrite and in quartz. Chalcosite and covelline form rare, irregular shaped allocations in thin quartz veins. The size of sulfide allocations is from 0.01 to 0.03 mm. [ABSTRACT FROM AUTHOR]