The Purpose of the paper is to identify and describe the ore belts of intraplate tectonic environments on the territory of Central, Southern and Eastern Transbaikalia. Results. In earlier works we have identified and described metallogenic belts of intraplate nature. This article deals with the ore belts as their constituents. Within the Chikoy-Shilkinsky belt we distinguish Chikoy, Onon-Turinsky, Agin, Nercha-Tungir, Shilka-Amazar ore belts. The Kerulensko-Argunsky metallogenic belt includes the Priargunsky and Gazimur-Uryumkan ore belts. Geodynamic conditions are determined by the formation of deposits in the belts, the foundation of which is made up of terranes of craton, oceanic and other nature. The cross-linking and overlapping complexes that are predominantly of Caledonian, Hercynian age are represented by volcanic, plutonic, terrigenous-carbonate formations; intraplate basically Cimmerian rock complexes refer to volcanic-plutonic and terrigenous formations of riftogenic zones. Ore zones of intraplate environments feature a wide range of deposits: tin, tungsten, gold, molybdenum, uranium, fluorite, polymetals. The hydrothermal ore formation processes of the Mesozoic metallogenic epoch prevailed. Conclusions. Most of the ore clusters and fields of intraplate belts are included in magmatogene-ore systems of plutonic or volcanic-plutonic types associated with fault zones. Under complex combination of microterranes and cross-linking complexes favorable for hydrothermal ore formation conditions predominantly took place in ancient hard blocks where deep splits were formed. The latter controlled magmatism and ore deposition (Muya, Urulungui and other micro-terrains).

The purpose of the work is to evaluate the occurrence prospects of various formational and genetic types of diamonds in Olondo greenstone belt as well as to justify the presence of noble metal mineralization associated with dynamometamorphic transformations of the magmatic rocks of basic composition. Methods. The study used the following research methods: compilation of a schlich-mineralogical map of diamonds and their satellite minerals distribution in loose sediments. Schlich testing was accompanied by the lithologic-petrographic study of boulder and pebble, rubble and gravel, deluvial-eluvial disintegrations and natural outcrops of rocks at the sampling points of primary concentrates. Petrographic, mineralogical and geochemical study of the basite-ultrabasic rocks of the complex was carried out using microprobe, X-ray diffraction analysis and other methods. Results. For the first time metakimberlites have been identified. Difluorinated pyroxenites and gas explosive structures have been discovered. The meta-rocks of komatiite series of the Olondo belt have been compared with the diamondiferous komatiites of French Guiana. Conclusions. Kimberlite and komatiite formational genetic types of diamond fields are predicted. The features of probable diamondiferous potential of difluorinated pyroxenites and gas explosive structures are specified. Manifestations of ore gold are found in dynamometamorphites on basalt komatiites, which are the main rocks of the tholeiitic series. Complex sulfide ores (Cu, Ni, Co) with noble metals are forecasted in addition to actual gold ore fields.

The purpose of the publication is to estimate the fluid sources of the epithermal fluorite deposits of the Western Transbaikalia by analyzing the isotope composition of oxygen, carbon, hydrogen and sulfur. Methods. The isotopic compositions of oxygen in silicates as well as carbon in carbonates are determined by V.F. Posokhov in the Geological Institute SB RAS. Results. The isotopic composition of oxygen in quartz is characterized by low δ¹⁸O (-3.4 - + 2.6 ‰). Pyritic sulfer of these deposits is also enriched by the light isotope δ³⁴S (from -1.8 to -7.7 ‰ δ³⁴S). The value of δ³⁴S varies from +0.4 to -9.7 ‰ and is -3.75 on the average for seven fields. Conclusions. The isotope studies indicate a deep source of sulfur, which underwent changes in the process of its rise from the magma pocket to the upper horizons. The composition of the fluid is indicative of the participation of water from the meteor source caused by recycling processes under the influence of shallow underlying basite pluton.

The Purpose of the paper is to study the features of rare-earth element (REE) geochemistry in limestones and post-sedimentation products including fluidolites, argillisites and calcite onyxes of the carbonate stratum of the Torgashino limestone deposit. Methods. The mass-spectrometry method with inductively coupled plasma is used for studying the REE behavior. The tests have been carried out in the multiple-access center “Analytical Center for Natural Systems Geochemistry” of the Tomsk State University. Results. The features of REE geochemistry are considered in the Torgashino suite limestones and fluidolites, argillisites and calcite onyxes contained in them. The distribution spectra of REE, Eu (Eu/Eu*), Ce (Ce/Ce*), light REE / heavy REE and other have been studied. Conclusions. Argillisites penetrating carbonate strata are characterized by the input of all REE while limestones and low-temperature hydrothermal formations in the form of calcite onyx have been formed in the presence of removal of both lanthanides and heavy REE. The analysis of REE distribution allows to make a conclusion on the different nature of argillisites which are the product of the fluidization explosive process and Torgashino suite limestones, which these processes were imposed on.

Purpose. The article deals with the forecasting method of brine-saturated zones with the abnormally high formation pressure (AHFP) in intrasalt carbonate reservoirs in the section of the lower Cambrian of the South of the Siberian platform according to the data of the near-field transient electromagnetic sounding. Methods. The method of near-field transient electromagnetic (TEM) sounding is used to determine the resistivity and conductivity of rocks composing the section. Results. Comparison of the results of prospect and exploration well drilling and the results of near-field transient electromagnetic sounding shows that the lateral gradient of geoelectric parameters allows to delineate potentially dangerous brine-saturated zones. Conclusions. The maps of longitudinal conductivity/resistivity as well as the maps of the resistivity/conductivity gradient of Belskaya suite of the lower Cambrian have been compiled. The criteria for the identification of gradient zones associated with the intrasalt carbonate brine-saturated reservoirs collectors have been determined.

Purpose. The research is aimed at studying the behavior of space and time characteristics of the fields of induced polarization caused by electric and magnetic sources typical for geoelectric settings of the south of Siberian craton. Methods. Numerical simulation of the electromagnetic field is used to calculate the transient characteristics of a typical geoelectric model. The sensitivity of non-stationary electromagnetic sounding towards the measurement of induced polarization effects is estimated on the basis of model data analysis. To measure the depths of the polarized layers spatial inversion is applied. Results. Variations of the the polarizability coefficient and depth of the polarized layer have been analyzed for one of the 3D TEM sounding areas within the North-West part of the Nepa arch. Сonclusions. The use of the magnetic source allows to improve the reliability of the studies of conductivity and polarizability of the geological section of the south of the Siberian craton.

The Purpose of the paper is development of the methodology for determining the volume of accessed and prepared reserves for complex structure ore deposits on example of the Golets Electricheskiy field. Methods. The study involves the following methods: analysis of existing concepts of prepared and accessed reserves, known methods of their determination, documentation rating the volumes of these reserves; analysis of mining and geological conditions of ore body occurrence in the complex structure ore field Golets Electricheskiy, deposit development technology and parameters; justification of the methodology for determining the volumes of prepared and accessed reserves. Results. The proposed methodology for determining the accessed and prepared reserves has been tested as applied to the conditions of the deposit Golets Electicheskiy. The optimal ratio of the lengths of excavating blocks for each of the horizons involved in simultaneous mining is determined. Conclusions. The length of excavating blocks on the horizons should be justified taking into account the specific operating conditions of the deposit, as well as the conditions of ore body occurrence. Since this paper takes the volumes of the prepared reserves according to the normative documents it is necessary to develop a methodology for determining the volumes of prepared reserves for each horizon involved in simultaneous mining.

Purpose. A classical problem of fluid mechanics involving the study of liquid flow in the eccentric channel has, in particular, the practical application in the process of flushing of controlled directional wells with horizontal ending. Transport of destroyed rock particles from the wells of the specified profile by the flow of flushing fluid is a challenging theoretical and practical task. The study of mud transport in field and laboratory studies has showed the multidirectional impacts of such characteristics of the flushing fluid as its viscosity and density in the turbulent flow regime. The purpose of the article is to study the specified multidirectionality on example of researches of different authors devoted to drilling mud carrying capacity. The Methods used include a comparative analysis of the influence of rheological parameters and density of polymer-containing flushing fluid on the minimum flow rate of the flushing fluid at which the precipitate is not formed. Results. Comparison is given to the influence of density of the studied flushing fluids and their viscosity on the optimization parameter which is taken as the minimum flow rate of the flushing fluid that fully extracts solid particles from the eccentric annular space of the experimental installation. The densities of solutions are calculated by the data on solution viscosity. Consideration is given to the aqueous solutions of carboxymethyl cellulose (CMC) and its derivatives as well as aqueous solutions of glycerine. Conclusions. It has been found out that the use of aqueous glycerin solutions as flushing fluids increase the carrying capacity of the latter due to higher density as compared with the solutions of CMC. The experiments that determine the carrying capacity of drilling fluids should be set taking into account both rheological parameters of the liquid and its density. The reduced viscosity of solutions can be used for this purpose by transforming its values into density.