Vol 481, No 1 (2018)

As exemplified by cobalt–bearing Fe–Mn crusts (ferromanganese stromatolite) of the Magellan Seamounts (Clarion–Clipperton Province), the main stages of the structural evolution of bacterial communities have been recognized. It has been demonstrated that the change of the stages is caused by the effect of major tectonic, volcanic, and other geological events.

This study demonstrates rock-magnetic and paleomagnetic investigations of Devonian and Mesozoic deposits of Kotelny, Stolbovoy, and Great Lyakhovsky islands. The results indicate that local remagnetization took place on the southwestern periphery on the archipelago of the New Siberian Islands. A comparison of new data with the apparent polar wander path for Siberia shows that the remagnetization happened during collisional events between 140 and 80 Ma and affected only the marginal part of the terrane of the New Siberian Islands that was directly facing the deformation front. The consistent younging of the remagnetization age from the south to the north indicates dextral rotation of the terrane of the New Siberian Islands during its collision with Siberia.

The results of study of the Bobruisk ring structure (Republic of Belarus) containing ~80 rare rockforming and accessory minerals are reported. Among them are native (Fe, Cu, Sn, Zn, Pb, Ag, Mo, W, Al) and intermetallic (Fe, Cr, Ni, Mo, B, N, C, Si) compounds, natural alloys (Fe–Cr, Fe–Cr–Mo–W–B; brass (Cu–Zn–Pb); and bronze (Sn–Pb–Zn–Cu)). They are observed as segregations of various shapes and sizes, as well as their aggregates. The formation of mineralization is controlled by reduced mantle fluids enriched in H₂, CH₄, CO, Si, N, and O and stimulating accumulation of rare elements as native and intermetallic phases, alloys, rather than isomorphic impurities in minerals.

The results of sporoderm studies for Paleozoic spores are obtained for the first time on a nanotomographic scanner. They are comparable to the results obtained on a scanning electron microscope (SEM) and transmitting electron microscope (TEM), verifying the interpretation of structures of the external and internal structure of the sporoderm for the objects studied. A nanotomographic scanner enables us to carry out complex studies of different sporoderm projections and to visualize the relationships and arrangement of its components without damaging the integrity of the object and losing unique Paleozoic material. Application of a nanotomographic scanner also reduces the time taken for object preparation for examination on a SEM or TEM. The nanosculpture of the exosporium of Devonian Kryshtofovichia africani Nikitin megaspores is revealed to show its two-layer structure, with the thicknesses and locations of the layers established.

It has been found that the main oil fields in Western Siberia are attributed to Triassic rifts, because the rifts drain the upper mantle, and the deformations of the sedimentary cover are determined by the basement. On average, the thickness of the basement is 14 times greater than that of the sedimentary cover. Taking into account the mean strength (153 ± 10 MPa) of the basement rocks, the basement strength is two orders of magnitude greater than the strength of the sedimentary cover. The sialic blocks, considered as Precambrian, are composed of light granites and metamorphic rocks. They ascend to the level of the upper crust at the time of Triassic rifting and continued to emerge. As a result, antiforms were formed above the sialic blocks in the sedimentary cover; these antiforms were filled with oil.

The results of the first GPS measurements along the geophysical profile that intersects all major geological structures of the Osetiya region of the Greater Caucasus are presented. The results of the measurements are interpreted in comparison with those of neotectonic studies and data on the deep structure.

The zircons in granitoids from the basement of the Verkhnerechenskii oil exploration area (Yamal Peninsula, West Siberia) were studied. The U–Pb age of zircons was evaluated as 254.0 ± 3.0 Ma. It was found that the inclusions in zircons are represented by various minerals: fluorapatite, titanite, monazite-(Ce), albite, quartz, chamosite, and calcite. Most likely, the latter two minerals were formed separately from zircon but belonged to later secondary minerals (the rock propylitization products). In general, the accessory zircons and inclusions belonged to the “granite” association and crystallized synchronously in the Upper Permian.

The influence of the acid–base properties of humic substances in natural waters on the buffer capacity value is considered. An alternative way of calculation of the ANC parameter taking into account the dual nature of the humus organic of waters is proposed. Zonal aspects of the distribution of natural waters over ANC values are evaluated, and the features affecting these parameters are singled out.

This paper presents an analysis of the mass spectrometry measurement data for the ion composition of the upper atmosphere at altitudes of 810–830 km. A radio frequency mass spectrometer RIMS was mounted on the Meteor-M 1 and 2 spacecraft that were launched in 2009 and 2014. The measurements were carried out by the contact method. The analysis of the seasonal data from January 1, 2016, to January 1, 2017, reveals a seasonal variation in the oxygen ion concentration associated with the Sun’s position. An increase in the O⁺ concentration for the South Pole and a decrease for the North Pole are observed in the regions of magnetic anomalies. The greatest increase in the ion concentration is detected in the region of the Brazilian magnetic anomaly. There are also minor increases in the O⁺ concentration that can be associated with the North American Anomaly over Yellowstone National Park.

This paper presents a summary of the quantitative substantiation for four main patterns relating to the changes in the chemical composition of mine waters in Eastern Donbas. The patterns and their origin and impact on the environment are characterized. This makes it possible to solve current practical and theoretical issues: to predict the main components of the environmental contamination, develop standards for treatment facilities, and forecast the transformation in the composition of surface waters, ground waters, and mine waters, and to solve successfully other ecological issues in Eastern Donbas.

The results of experiments on dissolution of diamond in a Fe melt with variable concentrations of S at high P–T parameters are presented. It is established that the maximal degree of diamond dissolution occurs at a sulfur concentration of 15 wt %. With decreasing or increasing S content, dissolution of diamond slows down and almost does not occur during the period of the experiment (60 min), when the “eutectic” composition is gained. In contrast to a pure Fe melt, the presence of S decreases the carbon solubility and, therefore, reduces the aggressiveness of metal melt in relation to diamonds, thus, stimulating their preservation in the Earth’s mantle, especially if the concentration of S exceeds that in the “eutectic” composition.

The results of mineralogical–geochemical study of the Albaza gold deposit (Khabarovsk Krai) are presented here. The ore mineral assemblage, in addition to already known sulfides of iron, arsenic, lead, zinc, and copper, contains sulfides of Sb, Bi, and Mo, as well as native bismuth, bismuth tellurides, cobalt sulfoarsenide, nickel sulfoantiminide, silver sulfobismuthide, lead–antimony–bismuth sulfosalts, and oxides of tin and titanium, among others. These features of the ore chemical composition suggest attribution of the deposit to a gold–trace metal formation. The genesis of the deposits of this formation is related to granitic magmatism that occurred at the transform continental margin under conditions of movement of the lithospheric plates.

The primary data are presented on gas chromatography–mass spectrometry of volatile material in diamonds from the placers in the northeast of the Siberian Platform. The new data obtained testify to the crucial role of hydrocarbons and their derivates in the processes of diamond formation within the Earth’s mantle. It was shown that the registered variations in the composition of volatile components in the treated diamonds were caused by a combination of processes including the transformation of redox conditions of the crystallization of diamonds.

Strong vibrations of the Earth’s crust in the frequency range of 7–9 Hz, referred to as the “voice of the sea,” have been recorded in the course of processing synchronous experimental data obtained during recording of variations in the deformation of the Earth’s crust using a shore laser strainmeter, atmosphere pressure variations using a laser nanobarograph, and hydrosphere pressure variations using a laser meter for hydrospheric pressure and wind velocity variations. The nature of these vibrations and their transformation to adjacent geospheres have been discussed.

The electric state of the near-surface atmosphere up to a height of 400 m is investigated using a tethered balloon with a measuring platform and a ground-based information-measuring complex of the Borok middle-latitude geophysical observatory. For the first time, measurements were taken simultaneously for vertical profiles of the atmospheric electric field, polar electrical conductivities, size distribution of aerosol particles, and the volume activity of radon, which have allowed estimating the average values and variability of the space charge density and conduction current in the atmosphere. The height dependence of the electric potential with respect to the Earth’s surface and electrical resistance of the near-surface atmospheric column under different conditions of the temperature stratification is studied.

This paper shows that the number of aftershocks with a relative magnitude does not depend on the magnitude of the main shock, and, in global and regional consideration, it is characterized by an exponential distribution that is similar to the Gutenberg–Richter repeatability law. This type of distribution makes it possible to give a simple and adequate interpretation of Bath’s law.

The joint impact of natural and anthropogenic factors determining the quality of waters in the river basins of the White Sea catchment area is assessed on the basis of control parameters characterizing the potentials of pollution and self-purification. A diagram of the catchment area zoning has been obtained, which can be used to justify environmental protection measures, as well as to generate strategies for socio-economic development of the territories.