The article discusses the problem of the nature of high-alumina garnet granulites from Sutam River (Aldan Shield). The studies revealed that the majority of detrital grains have U-Pb age of up to 1.92 Ga; however the zircon grain of 3.94 Ga has been for the first time discovered in Russia. This age is estimated as the upper limit of the Hadean eon. The goals of the present studies were to reveal the petrogenesis of garnet granulites and to find out the origin of the Hadean zircon in these garnet granulites and the mechanisms of injection diapirism of garnet granulite body to the upper horizons of the crust. The comparison of garnet granulites and middle crust showed that the granulites are enriched in the whole spectrum of rare earth elements (except of Eu) as well as Al₂O₃, U, Th and are depleted in Na, Ca и Sr (the most mobile elements). This in combination with other geochemical indicators suggested the granulite protolith as an upper part of the allite zone of middle crust weathering, formed in arid climate. The Hadean zircon grain is regarded as having been captured from the granites of middle crust. The diapirism of garnet granulites (with the captured Hadean zircon) proceeded during the Paleoproterozoic thermotectogenesis of the Aldan shield which were accompanied by the horizontal propagation of deep-seated granite-anorthosite tectonic flows from the plume’s center to its periphery. During the movement of these flows the fragments of the lower and middle crust were shifted both laterally and vertically. When they moved vertically they were discretely intruded in the upper granite-gneiss crust (1.83-1.82 Ga) under high pressure. The 3.94 Ga zircon is comparable with the Hadean zircons from Acasta orthogneiss (Canadian shield, 4.03-3.94 Ga, SHRIMP and ID-TIMS).

Earlier, we considered the features of the redox changes in the near-bottom layer of water in the sedimentation basins that existed during the Late Riphean and Vendian in the eastern and northeastern (in modern coordinates) margins of the Baltic. It is concluded that fairly pronounced variations in the values of a number of redox environment indicators in the Upper Riphean deposits suggested that accumulation of sediments in some regions occurred in dysoksis or close to anoxic conditions. Opposite in the Vendian oxidation conditions predominated in the near-bottom waters. In the present publication, these representations are verified by data on variations in Vendian clay rocks of the of the Th/U values. Analytic data obtained by ICP-MS in IGG UB RAS (Ekaterinburg) were used to analyze the features of the change in this parameter. A total of ≈380 samples of shales and mudstones were analyzed. The average Th content in these samples is 12.0 ± 5.4 ppm, in average post-Achaean Australian shale (PAAS) and upper continental crust (UCC) are 14.6 and 10.5 ppm, respectively. For U, the same parameters are 2.1 ± 1.1, 3.1 and 2.7 ppm. The value of Th/U_av for the Vendian shales of the east, northeast and north of the East European platform is equal to 5.8 ± 2.0 (in PAAS and UCC - 4.7 and 3.9 respectively). In the clay rocks of the Vendian of the Southeast White Sea, Th/U_av varies from below upward along the cross section from 5.8 ± 3.4 to 6.9 ± 2.3 without any definite regularity. The Vendian shales and mudstone of the southern part of the Vychegda trough have the Th/U_av value from 3.5 ± 1.1 to ≈5.0 ± 1.7. Dark-colored low carbonaceous shales of the Buton Formation of the Lower Vendian Serebryanka Group (the Middle Urals), which we considered earlier as deposits formed in a basin with distinctly oxygen-free sedimentation conditions, have the Th/U_av 5.9 ± 1.2, and, most likely, do not refer to sediments of stagnant environments. The new data on the distribution of Th/U values in the clayey rocks of the Valdai, Serebryanka, Sylvitsa, Asha, Kairovo and Shkapovo groups correspond to the idea of the accumulation of these sedimentary formations under conditions of dominance of oxidation environments in very shallow sedimentary basins, some of which may not were actually marine. They emphasize the complex/non-linear nature of oxygenation of the ocean, which began at the end of the Late Riphean and continued in the Vendian, with the inversion of “oxygen environments” in some large sedimentary basins or parts of them in the Early Vendian, to the Vendian and Cambrian boundary, and actually in the Cambrian. Obviously, not only global, but also local factors had a significant impact on this process.

Continuous sequence of the boundary carbonate sediments of the Silurian and Devonian in the Ludford - Lochkov interval (Kupruk and lower part of Madmon Formation) have been studied in the Zeravshan-Gissars mountainous region of southern Tian-Shan, Kitab State Geological Reserve, Uzbekistan. The data comes from the stratotype section and some additional small sections in the Obi-Safit Gorge.The Kupruk Formation (Ludford-Pridolian) is composed of limestone and irregularly spotted dolomitic limestone containing numerous dilapidated bioherms, intraformational breccias, dolomite interlayers, siliceous connections. The lower part of the Madmon Formation (Lochkov) is represented by massive micritic and micritic-clotted limestones with coral and amphiporous biorstroms and rare carbonate breccias. Despite the abundance of organic remains, in the section there are no finds of biostratigraphic frames established for the standard boundary of the Silurian and Devonian due to zonal species of graptolites and conodonts which absents here in the border interval. The Obi-Safit section was analyzed from sedimentary, cyclostratigraphic and event-paleogeographic positions. Structural-genetic types of rocks have been established, their typification has been carried out, and the features of the Kupruk and Madmon biota have been studied. The characteristic of paleogeographic environments of precipitation formation is given. According to the intensity of the hydrodynamic effect on bottom, sedimentation rate and salinity of the bottom waters, complexes corresponding to the energy zones of the M. Irwin profile are distinguished: Y (predominantly high-dynamic, shallow water) and Z (mostly low-dynamic shallow water). In the section of Obi-Safit there are 12 transgress-regressive cyclothems 10 to 50 m thick. For the Kupruk Formation, an ideal cyclotema consisting of seven structural-genetic types of layers was reconstructed and paleogeographic model of their distribution was made. For the first time determinations and images of foraminifera and algae from this section are given. The Kupruk strata were formed in a basin with increased magnesium content and a frequent change in the hydrodynamic regime. Sedimentation took place with pauses, which were accompanied by exposure and drying of the bottom or its partial dissolution. The Madmon sequences accumulated under more stable environment with a relatively higher sea level standing in conditions of shallow normal marine sedimentation environments located below the base of the wave destruction. The maximum of the transgression within one cycle is determined by the presence of organogenic buildings, and the regression maximum is due to the appearance of carbonate conglomerate-breccias, dolomites and dolomitic limestones. The currently used Silurian and Devonian boundary in the Obi-Safit section is lolocated near 335 meters from the base of the section, but it has no a biostratigraphic and facies evidence. Due to the lack of biostratigraphic standard for this boundary, it is proposed to use the paleogeographic event traced in the west of the Zeravshan Range, although its accuracy is not of high grade. It is caused by the disappearance of isolation of this territory, the subsequent penetration of waters of an open sea basin and fixed by the presence of the numerous crinoid fragments in the upper part of the IX cyclotema. The first appearance of abundant fragments of crinoid stems is located on the 295 meter of the section.

Territory Baltic shield is well understood and the identification of innovative geological formations rare stroke of luck. Thanks to the Russian Geographical Society in the summer of 2015 an integrated expedition to study the nature of the little-known islands of the Outer Gulf of Finland was carried out and found, much quartz rocks (SiO₂ more than 90%) that compose most part of the island Bolhoy Tyuters. As a result of complex studies including petrogeochemical, microprobe, isotope, thermobarogeochemical investigations and chromatographic analysis of gases, it can be asserted that these rocks are secondary quartzites formed under the influence of carbon dioxide solutions. The presence of shadow structures of migmatites, as well as mineralogical features of quartzites, suggest that the initial rocks, on which secondary quartzites were formed, could be shales of the svecofennian complex. The temperature of homogenization of gas-liquid inclusions is 330-370°C, which indicates a high-temperature facies of secondary quartzites. The age of the dikes of the granite composition, which break through secondary quartzites, is close to 1660 and 1680 million years, which is somewhat older than the main phase of rapakivi granites (1650-1550 my) and coincides with the pre-Riphean weathering era, at the end of which the formation of the largest “type of disagreement” occurred. The formation of secondary quartzites of B. Tyuters, as well as for most classical manifestations of this type, we associate with the fluid-explosive activity of volcanoes preceded of rapakivi granites, whose products, in the form of basic and acidic lavas, were preserved as part of the Early Riphean strata located on the island Hogland. Considering the huge resources of these quartzites (more than 370 million tons), this manifestation is very promising for high purity quartz raw materials, close to the North-Western industrial area and St-Petersburg. The formation of a subhorizontal plane controlling the formation of a deposit of secondary quartzites and Early Riphean sediments and rapakivi granite intrusions, we associate with the tectonic activity of the marginal part of the Baltic Shield, known as the Polkanov lineament.

The study of minerals-prisoners in accessory zircons is gradually evolving into an important geological-petrological task. Such a study can show not only the earliest mineral rock association, but also evaluate the “sealed” mineral paragenesis of zircon, which in turn indicates whether the accessory zircon is native to the host rock or redeposited (alien). In the present work, the mineralogy of zircon from granitoids of the crystalline basement of the Verkhnerechensk oil-exploration area (the southern part of the Yamal Peninsula, Western Siberia) has been studied. Granitoids are represented by homogeneous light gray fine-grained variety of biotite-quartz-feldspar composition and refer to monzoleucogranite, which formed over the sedimentary substrate, most likely under conditions of late orogenic surrounding. The time of magmatic intrusion and crystallization of granites according to the data of U-Pb dating of zircon (measurements carried out on the ion microprobe SHRIMP-II) is estimated as Late Permian (254.0 ± 3.0 (MSWD = 1.6) Ma). It is established that inclusions in zircon are represented by various minerals - fluorapatite, titanite, monazite-(Ce), albite, quartz, chamosite and calcite. The last two minerals, apparently, were not formed together with zircon, but are later secondary minerals formed as a result of the propylization of the rock. The time of secondary changes in the granitoid supposedly occurred in the Late Triassic, as one of the zircons gave a U-Pb dating of 204.7 ± 2.6 Ma. In general, accessory zircons and mineral inclusions contained in them belong to the “granite” association, and, apparently, are native to the enclosing monzoleucogranite.

The distribution features of the volatile components (H₂O, H₂, CO₂, CO, H₂S, SO₂, CH₄ and N₂) was investigated by method of pyrolytic gas chromatography in the ore-free and ore-bearing rocks of the low-sulfide PGE deposit Loipishnyun of the basal structural type, which localized within Monchetundra mafic massif of the Kola region. It was established that PGE ore, compared with the ore-free rocks are higher overall fluid-saturated, higher contents of H₂O and especially H₂S and SO₂. In the ore-free rocks, in contrast to the mineralized one, was revealed higher concentrations of CO, H₂ and N₂. H₂S and SO₂ play the main role to the process of the platinum-metal ore formation. The contribution of these components at the initial stage of the platinum-metal ore genesis is equivalent, as evidenced by the close values of positive correlations of these volatile compounds with platinum group metals and ore elements. With further decrease of temperature in the process of the ore genesis are dominate by the hydrogen sulfide, which has a high positive correlation mainly with copper and platinum group metals. The obtained results suggest that the process of the platinum-metal ore genesis proceeded in a wide temperature range from 1050 to 450°C. It began in late-magmatic, postcumulus stage (1050-850°C) under variable redox conditions and continued with the gradual reduction of the temperature to 450°C in conditions decreasing sulfur fugasity.

In the paper, there are adduced the data of a thermobarogeochemistry investigation of fluid inclusions in apatite of magnetite-chlorite-carbonates rocks from ultrabasite Karabash massife. The rocks are carrying copper-bearing aurum (1.3-2.6 wt % Cu) and was formed at temperature in the range of 480-280°C and a pressure of about 2-3 kbar. The content of the inclusions corresponds to the salt system of H₂O-NaCl and the salt concentration in the solution 3.7-8.8 wt % eq. NaCl. Fluids gas components, extraction by pirolysis up to temperature 450°C, are described by a system C-H-O with an insignificantly amount of nitrogen. In fluid composition presents a small amount of the reduced gasses - CO, H₂, CH₄, hard carbon-hydrates (C₂H₄, C₂H₆, C₃H₆, C₃H₈ etc.). Adduced comparative analysis of fluid composition and the degree of oxidation fluid gas component (O_fl = CO₂/(CO₂ + CO + H₂ + CH₄) during the forming magnetite-chlorite-carbonate rocks, the rodingites and the listwenites. It is established, that carbon acid part of mole in fluid (X_CO2) grown from extremely low value by the forming of rodingites with copper-bearing aurum (<0.007) to high value by the listvenitization (0.137). Magnetite-chlorite-carbonate rocks and the calcite veinlets, in the rodingites with copper-bearing aurum, occupy intermediate position by the value X_CO2. In the same time, reduction regime of the forming rodingites (O_fl = 0.14-0.35) is replaced on oxidation one by the forming of magnetite-chlorite-carbonate rocks (O_fl = 0.73-0.92), calcite veinlets, in the rodingites (O_fl = 0.83) and also the listwenites (O_fl = 0.77).

The deposits and displays ore of gold in the Mezozoic potash alkaline massifs Aldanskiy shield was the research objects. There are Rybinovoe and Novoe gold deposit in the Rybinovskiy alkaline complex and displays of gold in the Yakokutskiy, Yllymakhskiy, Tommotskiy and Mrachniy alkaline massifs. It was developed a complex searching criterions (magmatic, structure and geomorphological), straight and indirect indications of streaky-dessiminated gold mineralization in potash alkaline massifs. As magmatic criterion display the close spatio-temporal connection gold mineralization in the sericite-microcline metasomatites in the stocks potash alkaline syenites. Structure criterion manifested in separation in limits potash alkaline complex the structure elements, which controlled gold mineralization in hydrothermal altered syenites. Geomorphological criterion intended for evaluation the level erosion cut of ores stockworks in the alkaline massifs by correlation areas of spread alkaline syenites and rocks of volcanic roof. The straight searching indications of gold mineralization in the potash alkaline massifs include indigenous outcrops and mechanical aureoles of dispersion ore-bearing sericite-microcline metasomatites, heavy mineral aureoles of gold in eluvial-talus deposits above ores stockworks, alluvial gold placer. The indirect criterions are near-ores sericite-microcline metasomatites, primary and second geochemical aureoles of gold, silver, copper, molibdenium, lead and zinc, as well as magnetic, gravitational and electric anomalys in the geophysical fields. For implementation searching works on this type mineralization are offered complex searching methods, which include searching route, lito-geochemical and heavy mineral search, geophysical, minig and boring works. The same complex of searching criterions and indications gold mineralization in sericite-microcline metasomatites of alkaline massifs, suggested for use for implementation searching works in other provinces potash alkaline rocks (Western Aldan, North Baikal, Ural, North Kazakhstan, Central Kazakhstan, Armenian), perspective on this type gold mineralization. The use suggested predication works allowed are divided potentially ore-bearing areas in potash alkaline massifs on degree their prospective and single out immediate sections for implementation searching works on the gold.

The article is devoted to radiometric studies within the Kirov-Kazhim (KKA) and the Pechora-Kolva aulakogenes (PKA). KKA is the first-order structure of the Volga-Ural anticline, which is located within the ancient East European Platform. The PKA is located in the central part of the Timan-Pechora Epibaykal plate. The aim of the research was to develop a technique for express emanation survey of aulacogenes, to reveal the patterns of spatial variations in the volume radon activity (VRA) in soil air and to estimate of the fault zones activity. Studies were carried out on the western and eastern sides of the central and northern parts of the KKA and the central part of the PKA western side. The fault zones were identified according to the seismic methods data, where large amplitudes of vertical displacements were clearly expressed in the seismic sections. The investigations were conducted during three field seasons within the KKA. In the first year, measurements of the VRA were made from the ground surface. In the following years, a borehole with a depth of 50 cm was drilled for each measurement. A borehole was necessary to reduce the influence of meteorological conditions and soil layer. Summarizing the results obtained in different years allowed concludes that within the fault zone the values of the VRA from the borehole were in the range from 200 to 2000 Bq/m³. The values of the VRA obtained from the ground surface was not higher, than 300 Bq/m³. In 2015-2016 years, express radon survey was carried out according to a previous method in the western side of the PKA. The results showed that the fault zones were clearly reflected in the radon field by elevated values of the VRA in the range 400-1555 Bq/m³. The highest values of the VRA was recorded within the faults which most closely approached to the ground surface. The results of the express emanation survey on the territory of two aulacogenes show that all the fault zones clearly appear in the radon field by increased values of the VRA. The maximum values of the radon activity correspond to tectonic dislocation, which most closely approached to the ground surface. Along the fault line values of the VRA can change. At different times within a single fault site, the VRA values can also fluctuate. The width of the increased values the VRA zone is always greater than the own width of fault. Thus, the spatial distribution of radon over the faults is estimated as quite complex, but using this method for complex study of fault tectonics is promising.