The study of submicroscopic structure of oxide ores revealed their similarity to the present-day bacterial communities. It is shown that the structure of cobalt-bearing crusts and ferromanganese nodules is based on bacterial mats, which permits identifying them as stromatolites and oncolites. The facts in favor of intense interaction between biofilms and the environment are found. The signs of mineral phase formation are registered as a result of biochemical absorption and assimilation of iron and manganese by bacteria.

Оn the basis of the analysis of the results of modern domestic, foreign and author's research, the problems of tectonic inheritance in the course of supercontinental cyclicity are considered, examples of it in the form of repeated manifestations of Wilson cycles within a specific zones, paleomagnetic data on the similarity of reconstructions of supercontinents of different ages are given. The deep, predetermining causes of this inheritance, consisting in the existence of weakened zones of the lithospheric mantle, controlling the processes of formation and decay of supercontinents, are shown.

Structural-geomorphological analysis of the modern relief allowed us to reveal Western Taimyr newest structure features and to show the significance of the structural forms shear horizontal displacements, as well as the manifestation of relief in some areas of previously formed thrusts. Since the Oligocene, neotectonic development of the Arctic was determined by Eurasian basin opening. This causes the activation of the North-Eastern faults in the region, which have the same stretch as the transform faults of Gakkel ridge spreading zone, which confirms the active development of this region at the present stage.

In this article there are the results of sedimentological, palynological and paleomagnetic studies of upper Cretaceous in Alan-Kyr section (Central Crimea). The nomenclature of rocks was specified, and their deep-water genesis was justified. According to palynologic data, the age of sediments is estimated as late Campanian, in the lower part of the section palynomorphs were not found. In the lower part of the section there was established a reverse polarity magnetozone — probable analogue of C33r magnetic chron, which base should be desirable to use as a primary attribute to determine the lower border of Campanian stage in the section according to Wolfring’s recommendation [Wolfgring et al., 2018]. The received data found a significant divergence microfaunistic dating of the section, conducted before [Bragina et al., 2016].

The history of study and hypotezis of origin unique phosphate microfossils — «conodont pearls» was considered. The material comes from the Middle and Upper Devonian sediments of the european part of Russia. Analysis of the chemical composition of the formations showed great similarity with other phosphate microfossils belonging to conodonts and fishes inhabiting the same paleobasins. Apparently, the morphological features and chemical composition suggests that the «conodont pearls» was the otoliths of the conodonts.

The paper is focused on characteristics of the peltaspermalean pteridosperms from the Lower Permian (Kungurian stage) of the Mazuevka locality (Kishert District of the Perm region, Russia). The paper is based on the material kept in the paleobotanical collection of the Earth Science Museum of the Lomonosov Moscow State University. The peltasperm seed-bearing organ is characterized for the Mazuevka locality for the first time. This organ is preliminarily determined in open nomenclature as Peltaspermum sp. General considerations by the present authors on the possible entomophily of at least some representatives of peltaspermalean pteridosperms are given.

The results of experimental studies of the macro- and microcomponent composition of pore solutions of bituminous clay-siliceous rocks of the Bazhenov Formation (BS) of Western Siberia, containing up to 12.63% Corg (“normal rocks”), as well as silt-sandstones from the “anomalous” section are presented. BS with a Corg content of up to 0.63% (“abnormal” rocks) obtained on the basis of a study of aqueous extracts from core samples. It has been established that pore solutions of “normal” BS rocks have a sulfate-bicarbonate-sodium composition, and “abnormal” ones have a hydrocarbonate-sodium chloride composition. In pore solutions of both “normal and“ abnormal ”rocks relative to ocean water, the following were noted: a) concentration of Mn, Co, Ni, Cu, Zn, Mo, Sb, Cd, Ba, V, Cr of various degrees of intensity; b) increased content of Cs, Pb, Ti only in pore solutions of “abnormal” rocks; c) reduced content of Li, B, Rb, Sr. A direct relationship was found between the contents of Li, B, Ba, Sr, U, Mo, Cd, Sb, and Ni with the content in the Corg rock. For V, Cs, Sb, Rb, Ti, Mn in pore waters, the relationship with the amount of Corg in the rocks is close to the inverse relationship. In the pore solutions of “normal” BS rocks, the Ba content is equal to or higher than the Sr content, which is anomalous with respect to the stratal waters of most oil fields and ocean water and, apparently, is associated with the peculiarities of the accumulation of organic clay deposits, since in “anomalous” rocks The BS content of Sr is two times higher than the Ba content, which is closer to the usual for most natural waters.

By analyzing the changes in seawater pumped to maintain reservoir pressure (FPD), the anhydrous granitoid reservoir of the White Tiger deposit, in which the cracks are partially filled with calcium minerals (calcite and lomontite), shows that these minerals interact with the injected seawater. Hydrogeochemical modeling of this process showed that cations of seawater are first sodium and then magnesium displace calcium from the lomonite exchange complex, which leads to precipitation of anhydrite and a small amount of calcite. The incoming water dissolves the anhydrite and precipitates it downstream, forming a gradually expanding annular region with a constant increase in the amount of precipitated anhydrite. As a result, there is a decrease in the permeability of the fracture medium due to the filling of the cracks with anhydrite. A large amount of calcium in the associated waters when they rise to the surface causes the precipitation of calcite in the production wells and surface equipment. The transition of drilling to ever greater depths, where the rocks contain lomontite almost everywhere, requires taking into account the phenomena of cation exchange between the injected water and the rock in the predictions of scaling.

The analysis of the content of ions in cryopeg different mineralization of the Yamal Peninsula. The regularities of changes in the chemical composition of cryopeg waters in the process of cryogenic metamorphism are revealed The ratios of the macro-components of the chemical composition of cryopegs allow us to conclude that the genesis of the initial solutions was different: marine and infiltration.

Estimation of leakage from riverbeds is an important task to quantify the interaction of surface and groundwater and to perform effective water management under arid climate conditions, where the leakage from riverbeds helps to maintain the existence of riparian ecosystems. One of the methods to estimate the leakage rate from the riverbed is to use the daily temperature signals of riverbed sediments. In present paper, the continues measurements of riverbed sediments temperatures in the lower reaches of the Heihe river (North-Western China) are used to calculate the leakage rate from the riverbed. The obtained results of the leakage rate calculations are compared with the results of inverse problem solution on a onedimensional model of heat and water flow. Good agreement of the calculated and model leakage rates is observed when a significant distance is found between temperature sensors (≥ 0,3 m) and between temperature sensors and riverbed surface (≥ 0,5 m).

The geological structure of two freshwater lakes (the Verkhneye and the Vodoprovodnoye) located near the White sea biological Station of the Moscow State University (the Kandalaksha Bay of the White sea) is considered for the first time according to the GPR data. The morphology of the top of the Archean basement, the structure of the Quaternary sedimentary cover and bottom relief were studied. Shallow marine sediments overlying the rocks of the Archean and a sequence of lacustrine-marsh sediments were identified using the drilling data in the Quaternary cover. Structural schemes were constructed for the main reflecting horizons, while isopach schemes were generated on the basis of the main sequences. The values of electrical resistivity and absorption coefficient are calculated and the possibilities of their use for the delineation of GPR facies are considered.

The results of determining acoustic and electrical properties of frozen saline soils (sand and silt) of massive cryogenic texture at different water content (3 values for each type of soil), salinity (7 values for silt and 5 for sand) and temperatures (–2, –4, –6 ᵒC) are given in the article. As a result, data on the high correlation between specific electrical resistivity and concentration of the pore solution and between ratio of a concentration of the pore solution to temperature and the velocity of longitudinal waves were obtained. Electrical resistivity can decrease by 2–22 times during the transition from a low-saline to a highly saline state and for longitudinal wave velocities only two times. Therefore, it is the electrical properties that are most suitable for the ranking of soils by the degree of salinity.

The solubility of fluorite in HCl and HF solutions with a variable concentration of Zr at 90, 155, 205 and 255 ᵒC and the pressure of saturated water vapor were investigated. The results showed that the solubility of fluorite increases with increasing concentration of zirconium. Using the OptimA program, the free energies of the ZrF₆^2– complex were determined from the experimental data, from which the dissociation constants of the reaction ZrF₆^2– =Zr⁴⁺ + 6F^- were calculated. The pK values were 29,86±0,13; 34,03±0,062; 38,28±0,033; 40,94± 0,079 at 90, 155, 205 and 255 ᵒС (saturated water vapor pressure).