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The paper presents the geochemical and isotope characteristics of rocks and the U-Pb age and Lu-Hf isotope composition of zircons from three plutons of Paleoproterozoic granitoids in the Sharyzhalgai uplift (southwestern Siberian craton). The age of granitoids of the Toisuk (1838 ± 6 and 1827 ± 9 Ma), Nizhnii Kitoi (1846 ± 7 Ma), and Malaya Belaya (1863 ± 16 Ma) plutons corresponds to the Late Paleoproterozoic collision stage and is correlated with the time of mafic magmatism. The studied rocks have a wide range of silica contents. The Toisuk pluton is composed of a range of rocks from monzodiorites to granodiorites (granosyenites) and granites; the Nizhnii Kitoi pluton, of granodiorites and granites; and the Malaya Belaya pluton, of leucogranites. The rocks of the three plutons are highly ferroan, enriched in LREE, Th, and HFSE, and correspond in composition to A-type granitoids. A characteristic feature of melanocratic granitoids of the Toisuk and Nizhnii Kitoi plutons is extremely high contents of Ba: 4080-1500 ppm and 1560-990 ppm, respectively. Based on analysis of experimental data on the melting of various substrates and the results of numerical computation, it is assumed that monzodiorite-granodiorites of the Toisuk pluton and granodiorites of the Nizhnii Kitoi pluton resulted from the differentiation/melting of a mafic source similar in Ba and Sr contents to intraplate continental basalts. The isotope compositions of zircon and melanocratic granitoids of the Toisuk (e_Hf from -6.0 to -10.7 and e_Nd from -5.3 to -10.2) and Nizhnii Kitoi (e_Hf from -5.0 to -8.1 and e_Nd = -4.0 and -5.1) plutons argue for the generation of their mafic sources from the enriched lithospheric mantle formed as a result of Neoarchean subduction processes. Vein granites of the Toisuk pluton and leucogranites of the Malaya Belaya pluton formed through the melting of quartz-feldspar (granodiorite) substrate. The contrasting isotope parameters of the Toisuk vein granites (e_Hf from -6.7 to -10.1, zircons, and e_Nd = -5.5, rock) and Malaya Belaya leucogranites (e_Hf from 2.9 to 5.9, zircons, and e_Nd from +0.7 to -1.9, rocks) indicate melting of the Archean and Paleoproterozoic crust, respectively. The more radiogenic Hf isotope composition of zircons from vein granites as compared with rocks of the Archean crust of the Irkut terrane is evident of the contribution of juvenile material to the granite formation.

Data on the mineralogy, geochemistry, and geochronology of zircons from plagioclase and spinel lherzolite and dunites of the Nurali massif are presented. The age of the main-type zircons from lherzolites (plagioclase ones, 446.2 ± 2.8 Ma, and spinel ones, 433.3 ± 3.4 Ma) and dunites (443.8 ± 6.9 Ma) suggests their synchronous crystallization ( T _av = 440 ± 5 Ma). The metamorphic age of zircons is 410-415 Ma. In addition to grains belonging to the main subset, the older grains with an age between 527 and 2045 Ma and newly formed metasomatic grains with an age of 380-385 Ma were found. The structure and REE patterns of most zircons from ultramafic rocks point to their magmatic origin, which is probably related to crystallization of a fluidized mantle melt.

We report preliminary experimental data on the interaction of zircon with the peridotitic assemblage olivine + serpentine at 2.5 GPa and 1400 °C. In these conditions, zircon is unstable and decomposes with the formation of baddeleyite. Therefore, it is unlikely that zircon could survive in ultramafic rocks for a long time in the presence of a fluid phase at high temperatures. Thus, rigorous constraints on boundary conditions are required for the use of zircon in the dating of high-temperature geologic processes.

This paper discusses the structure and facies variability of the Silurian mixed terrigenous-carbonate strata and presents new paleontological and biostratigraphic data. It attempts to refine the stratigraphic position and provide new lithologic evidence (markers) for regional manifestations of global sedimentary events (Mulde transgressive-regressive and Linde regressive events) in the Altai sections. The chronostratigraphic position of the Kuimov Horizon, a regional stratigraphic unit, has been defined based on graptolite and conodont faunas.

During the late Mesozoic and Cenozoic, the North China Craton witnessed a series of tectonic transition and deformation events, caused mainly by the subducting Pacific Plate and forming many petroliferous basins in eastern China and adjacent areas. Based on analysis related to the reconstruction of balanced sections, the comparison of subsidence rates, and the migration of depocenters in these basins, the tectonic evolution of these basins and their relationships with each other are clearly revealed. The evolution of the Bohai Bay Basin shows a migration from southwest to northeast. The North Yellow Sea Basin’s evolution developed northward, while the South Yellow Sea Basin evolution migrated southward. The evolution of the East China Sea Basin was activated from northwest to southeast. In combination with the subduction of the Pacific Plate, the conclusions of this study can be summarized in three aspects: (1) The structural pattern of the basin group is characterized by east-west trending belts and north-south trending blocks, (2) tectonic activities in the late Mesozoic-Cenozoic basins evolved from west to east in response to the westward subduction of the Pacific Plate, and (3) due to the collision of the Eurasian Plate and Indian Plate and the transitional pattern of the Tan-Lu Fault Zone from sinistral to dextral, the tectonic evolution of the basin group was centered in the Yellow Sea Basin, with the Bohai Bay Basin evolution migrating northward and the ECSB migrating southward.

Theoretical studies and methodical recommendations in pulsed electrical prospecting are based mainly on the technique of pulsed excitation with an instantaneous turn-off of direct current. In practice, the duration of current passage is determined by the depth of sounding and by economic and time expenditures. The pulse duration affects the late stage of the electromagnetic-field transient. At the early stage, it also depends on the turn-off front, which cannot be too short for technical reasons. On the solution of the direct problem, it is necessary to take into account the real parameters of the current pulse. Earlier it was proposed to use a special current pulse waveform to optimize sounding (the compensation transient electromagnetic method was implemented). We propose to look at the problem more broadly, in terms of separation of the nonstationary geoelectromagnetic field into TE and TM polarizations, which are excited by different sources. It turns out that the dependence of these polarizations on the waveform of the exciting pulse can be radically different in media with an insulating base.

The retrieved continuum absorption spectra in pure water vapor within near-IR bands 0.94 and 1.13 mm (10600 and 8800 cm^-1) are investigated. The continuum was determined as a difference between the water vapor absorption spectra measured using a Fourier transform spectrometer and absorption spectra of the water monomers calculated using the HITRAN2016 database. The work is aimed at estimation of the maximum error in retrieval of the continuum absorption coefficient, which is caused by uncertainty in spectral line parameters in HITRAN2016. It is shown that the calculated errors exceed other types of errors within the absorption bands under studied.

The WxSpe software package is presented, which automatically analyzes and reconstructs the parameters of spectral lines based on the multispectral approach. The software package developed uses the methods of the theory of pattern recognition and is a taught. The package allows one to automatically process large amounts of information, find lines in the spectra solve the inverse problem - determine the intensity, centers, and coefficients of broadening and shift of spectral lines or groups of overlapping lines. In the package, calculations with various model shape of the contour are performed. The numerical analysis of a typical situation is carried out, when the width of the apparatus function of the spectrometer turns out to be comparable or even larger than the line width. As a practically important example, measurements and analysis of the absorption spectra of pure water vapor and a mixture with nitrogen in the spectral range of about 0.59 mm are made; the comparison with the results of previous measurements and calculations is presented.

The technique for detecting and studying the optical and microphysical characteristics of aircraft condensation trails using the unique altitude polarization lidar of the National Research Tomsk State University (NR TSU) is described. The microstructure parameters of the ensembles of crystalline particles were estimated by comparing the elements of the backscattering light matrices (BSLM) obtained theoretically and experimentally. It is shown that the contrail appeared behind an aircraft formed in the atmosphere in 30-40 minutes after the emission of fuel combustion products from engines consists of small randomly oriented particles of ice, mostly columnar.

The study results of the atmospheric aerosol effect on the registered Earth’s airglow are presented. We used data from CIMEL CE-318 automated solar photometer, which is a part of the global terrestrial network (AERONET), and observational data of atomic oxygen emission lines [OI] 557.7 and 630 nm in the Geophysical Observatory of the Institute of Solar-Terrestrial Fhysis SB RAS (52°N, 103°E). The nonlinear dependence of the 557.7 and 630 nm emissions intensity on the aerosol optical depth (AOD) was revealed. An increase in the correlation coefficients was obtained for small AOD values (up to 0.5), and a decrease, for large turbidity. An observation interval with a high positive correlation between the 557.7 and 630.0 nm emission intensities and AOD, which is supposedly associated with extensive areas of forest fires, was identified.