Geochemical Indicators of “Camouflaged” Pyroclastic Material in the Upper Jurassic–Lower Cretaceous Deposits of the Eastern Russian Platform

Doklady Earth Sciences - Based on the results of studying the lithological–geochemical features of the Upper Jurassic–Lower Cretaceous mudrocks and black shales in the Eastern Russian...     

The influence of geodynamic factors on the lithification of sedimentary deposits in the stratisphere

The peculiarities of the processes of postsedimentary lithification and their dynamics in various geostructural areas (cratons, young platforms, and orogens) are considered. The direct and indirect impacts of geodynamic factors on these processes are substantiated.     

Convection Regime of the Development of an Impulse–Buoyant Transient Jet Submerged in a Homogeneous Fluid

An intergral model of a transient vertical impulse–buoyant jet is suggested. The model contains a universal equation describing the propagation of the upper boundary of the convection front depending on the strength of the point source of buoyancy and momentum. The convective regime of jet propagation is considered, which includes a class of self-similar solutions corresponding to the buoyancy sources, whose strength varies with time following power and exponential laws. The obtained numerical solutions are compared with available experimental data on the profiles of vertical velocity and buoyancy on the jet axis.     

A new approach to the automatic computation of partial volumes of river runoff with various degrees of pollution (a case study for the Selenga River)

Proposed are the methods and software package that enable estimating automatically the degree of the pollution of annual and long-term river runoff at the joint processing of large volumes of standard (routine) hydrological and hydrochemical information. As a result of computations, the individual quality certificate of river runoff was created for the part of the river under study. Computation methods include regulations concerning the parameters that connect the water runoff volume with water quality; the parameters that may connect the computation of the pollution degree using RD 52.24.643-2002 adapted for the partial volumes of the annual runoff according to these methods, with the subsequent classification of the pollution degree. The computation technique was worked out and used for the first time. The informativeness of estimates is demonstrated for one of the discharge section lines of the Selenga River.     

О ВЗАИМОДЕЙСТВИИ МЕЖДУ ВЫСОТНЫМИ АТМОСФЕРНЫМИ ВИХРЯМИ И НАЗЕМНЫМ ТЕЧЕНИЕМ

Summary It is shown that non-divergent vortices may induce, as a result of the resonance effect, a rapid surface development.     

Shock Wave Effects from the Impacts of Cosmic Objects with Diameters from 20 m to 3 km

Izvestiya, Physics of the Solid Earth - Abstract—Destruction on the Earth’s surface caused by a shock wave is one of the most important and dangerous effects from asteroid and comet...     

Climatic and environmental characteristics of Moscow megalopolis according to the data of the Moscow State University Meteorological Observatory over 60 years

Analyzed are the results of meteorological and environmental measurements performed over the 60-year period (1954–2013) at the Meteorological Observatory of Lomonosov Moscow State University. The significant positive temperature trend (0.04°C/year for 1954–2013) was obtained; it increased up to 0.07°C/year in 1976–2012. Considered are the features of seasonal variations of different atmospheric characteristics. Discussed are the type and causes of low-frequency changes in meteorological parameters, radiation balance components, radiation in different spectral ranges, and chemical composition of precipitation. Demonstrated are possible mechanisms of the more significant increase observed in air temperature in Moscow as compared with that in Central Federal District and their connection with the greenhouse effect in the urban atmosphere.     

Changes in the Period of Negative Superhumps of Type SU UMa Dwarf Novae. II. NY Her (2017 and 2020)

Astrophysics - Photometric studies of the type SU UMa dwarf nova NY Her were made during 2017 and 2020 at the Crimean Astrophysical Observatory and at the Sanglokh Observatory over a total of 77...     

Detailed mineralogical-geochemical study of a large spinel Lherzolite xenolith in alkali basalt of Shavaryn Tsaram paleovolcano,Mongolia

Mineralogical-geochemical data obtained on a large xenolith of spinel lherzolite from basanites of Shavaryn Tsaram volcano (Middle Pleistocene) provide evidence that the xenolith was affected by heat and fluid that came from the basalt melt and induced geochemical heterogeneity of the xenolith. Olivine crystals from the central portion of the xenolith contain much more CaO than this mineral from the peripheral zones of the xenolith as well as in xenocrystals of the host basalts. The large xenolith was unevenly annealed by the host basalt melt, and this predetermined the heterogeneous diffusion-controlled “purification” of olivine crystals from their CaO admixture. The xenolith is heterogeneously enriched in LREE and some trace elements (Zr, Hf, Nb, Th, and U), and their distribution demonstrates unclearly pronounced concentric zoning: these elements enriched the outer portions of the xenolith. The enrichment of the xenolith in LREE and other mobile trace elements is explained by their occurrence not only as structurally bound (isomorphic) components in minerals but also in the form of nonstructural admixtures (contaminant), as minute grains of compounds hosted in the interstitial space and tiny cracks cutting mineral grains. The enrichment of the xenolith in these admixtures proceeded via their infiltration-controlled introduction with fluid from the basalt along minute cracks.     

我国断层气测量在地震科学研究中的应用现状

氢气被认为是反应断裂活动最灵敏的地球化学组分之一。研究影响断裂带氢浓度动态变化的主要因素,是科学分析断裂带氢与构造活动关系的基础工作。本文基于河南内乡马山口断层气氢气浓度与辅助测项的连续观测资料,重点分析了氢浓度变化与地温、气温、气压的相关关系,确定了主要影响因素。结果表明,氢气浓度日变化极值介于气温和地温之间,极值点靠近地温一侧。使用逐步回归方法分析进一步证明,地温、温度对氢气浓度均有影响,但地温影响更显著,气压影响不显著。总体来讲,氢浓度会受到地温和气温的双重影响,但与地温关系更为密切。