On the basis of new materials this article deals with the structure and origin of a huge (up to 2 km) thick massif of acidic volcanic rocks located in a volcanic-tectonic depression in the Upper Chegem River in the North Caucasus. Discussion on the lava’s, rather than pyroclastic, origin of the main part of the rock mass as a result of repeated outpourings of lava flows, which formed the series of acidic volcanic rocks without interruptions with perfectly pronounced columnar jointing in a limited volume of a deep volcanic-tectonic depression, which was forming simultaneously with eruptions in the Late Pliocene. Volcanic rocks formed as a result of boiling silicate meltas the exit from the vent, which could be due to the nature of the phase transition of the supercritical water fluid.

The Katav-Ivanovsk transpression zone experienced at least two stages of tectonic deformations, and the sequence of deformations was approximately the same throughout the entire zone — from the Bakal-Satka fault in the south to the Suleimsky fault in the north. Three stages of the formation of parageneses were identified. The parageneses of the first and the second stages were formed in a pure shear environment, and the paragenesis of the third stage — in a simple shear environment. There are stylolites (S₁) parallel to bedding, and mineral veins (V₁) in the paragenesis of the first stage. Paragenesis of the second stage combines stylolites (S₂), mineral veins (V₂) and intergranular cleavage (S₂). In paragenesis of the third stage were distinguished schistosity (S₃), milonites (S₃), cataclasites, mica packets (SC-textures), and the rotation structures of porphyroblasts.

Significant amount of menshikovite (rare palladium and nickel arsenide) Pd₃Ni₂As₃ was found on the Eastern flank of the Oktyabrsky deposit (Norilsk ore field), near the contact of solid and impregnation sulfide Co-Ni-Cu ores among magnetite-plagioclase-fassaite skarns. Sulfide material of both ores consists of chalcopyrite, pentlandite, pyrrhotite and cubanite aggregates, which are the products of subsolidus transformations of high-temperature solid solutions Iss3, Iss4 and subordinate Mss; with interpositions of later Se-galenite. Menshikovite in association with mertieite-II, silver-gold (fineness 756–706), golden-electrum (fineness 694–672), kotulskite, moncheite, rare altaite, hessite, naldrettite and melonite forms small (up to 30 microns) metasomatic growths on the contact of silicate matrix and magmatogenic sulfide aggregates. The average composition of menshikovite is close to theoretical data: (Pd_2,98Ru_0,03)_3,01(Ni_1,89Fe_0,-08Co_0,01)_1,98 (As_2,94Se_0,04Bi_0,02Sn_0,01)_3,01. Sperrylite metacrystals cut the borders of menshikovite accretions as well as other minerals of precious metals and contain “corroded” inclusions. This association of minerals of noble metals has arisen under the increased activity of As, Te, Sb, Bi and low activity of Sn in fluids.
Menshikovite is typical for Pd-rich ores of the Oktyabrsky Deposit, while mayakite PdNiAs (another palladium and nickel arsenide) is relatively widely developed in ores of the Talnakh Deposit (Mayak mine and partly Komsomolsky mine) and the Norilsk-I. Perhaps, such a distribution of palladium-nickel arsenides is an element of mineral zonality of the Norilsk ore field.

Results from isotope dating of the Greater Caucasus crystalline basement in the Elbrus subzone of the Main Caucasus Range inside of the HT gneiss-migmatite area of the Gondaray Metamorphic Complex is discussed herein. The measurements of the zircons isotope composition were performed on the ion microprobe SHRIMP-II at the CIR VSEGEI (St. Petersburg). All zircon crystals from the gneiss sample N 526 show chemical zoning and an old clastogenic core. Almost all U-Pb isotope dating points toile on the concordant line of the concordia diagram and show a wide age range from 320–1000 Ма, partially obtained from clastogenic grains of the zircon from the initial pelitic sediments. The youngest ages (320 Ма) belong to regenerating zones of the zircon grains recrystallized during stage of the anatexis and migmatization. The other part of the age range 540–1000 Ма belongs to detrital zircons from different magmatic sources that existed during accumulation of the proto-metamorphic sediments. Several clastogenic zircon grains show a Cambrian age, which is an evidence for the Early Paleozoic age of the metamorphic protolith. Traditionally the age of the Caucasus crystalline basement was suggested to be Precambrian. The ages of rim zones of the recrystallized zircons (320 Ма) have a direct correlation with postmetamorphic granite ages of the Greater Caucasus. It is shown by termochronological modeling that cooling of the Gondaray Metamorphic Complex during a retrogressive stage, from the temperature of migmatite crystallization (650 ^оС) to the moment of biotite K-Ar isotope system closure temperature (350 ^оС), was relatively fast (rate of cooling 8–10 ^оС/Ma) at subisobaric conditions and during a time range about 30–40 Ма.

Various techniques have been tested (multi-acid microwave decomposition and sintering with soda) for preparing samples for the analysis of ICP-MS for samples with a complex matrix including an organic component for the subsequent determination of the microelement composition. For research, we used samples of bottom sediments: terrigenous clay (SDO-1), volcanic-terrigenous silt (SDO-2), calcareous silt (SDO-3), ferromanganese nodules (SDO-5), Baikal silt (BIL-1) and complex sediment sample of Baikal (BIL-2). The most effective sample preparation methods for the studied rock type are proposed.

The hydrogeochemical composition of groundwater in the Bodrak River basin (area of the geological practical studies and field works for students of SPbU, Lomonosov MSU, Dubna and Voronezh Universities) was investigated. The study determined role of lithology in the hydrochemical composition of groundwater and surface waters of the region. Three hydrochemical generations of groundwater have been identified by statistical analysis, geochemical features of groundwater in the region have been revealed, stable natural association of chemical elements in the groundwater of the Bodrak River has been obtained: Ba(2,0–58,2)–B(1,1–10,3)–Ag(3,2–8,6)–Sr(1,6–8,4)–Sn(3,4–4,9). The study analyzed the intensity of water migration of chemical elements in the groundwater and river waters of the Bodrak River, and the variability of the water migration coefficient was obtained along the river.

Based on the analysis and generalization of geological and geomorphological information, including new data obtained by the authors, we developed a scheme of activated Precambrian morphostructures of the Northern Ladoga area. When we compiled it, the severity of the ancient structures in the relief, the confinement of the epicenters of earthquakes, paleoseismic dislocations, helium and radon anomalies to them, as well as the results of the analysis of the movement of GPS points, computer and physical modeling on equivalent materials were taken into account.

Experiments on fluorine leaching from the rocks (alkaline agpaitic granite, dacite, and feldspathic-quartzy aleurite) by 0.005 M solutions of acetic, tartaric, citric, and oxalic acids were carried out. The previously revealed fact of decrease in the fluorine leaching by organic acids as compared with that by distilled water with an increase in acidity of solutions in the pH range from 6.3 to 3.5 is confirmed. According to the leaching ability in relation to distilled water, organic acids are formed a number: oxalic > citric > acetic ≈ tartaric. It is assumed that decrease in pH leads to sorption of fluorides as a result of the replacement of adsorbed hydroxyl ions. From this point of view, less intensive (compared with distilled water) fluorine leaching in acidic medium can be associated with sorption immobilization of fluoride ions in the solid phase. A positive correlation between amounts of leached fluorine and magnesium indicates the existence of a certain common, as well as not established mechanism for transition of these elements from minerals to aqueous solution.

Present the ore-metasomatic zonation of the Freedom area, one of the ore centers of the Malmyzh Au-Cu porphyry deposit. The central part of ore-mineralization zones composes of quartz-sericite and biotite-K-feldspar metasomatites which carry relatively rich gold-copper. Flank zones are composed mainly of phyllic and propylites. These zones are characterized by increase content of lead, manganese and zinc. A positive correlation was found in two groups of elements: Mo–Cu–Au and Pb–Zn–Mn. Based on the analysis of the vertical change in the contents of ore components and their relationships, presumably, modern erosional level takes upper-ore position.

The main lithological rock types typical of the highest carbon part of the section of the Lonmasi formation of the Lower Silurian age of the Sichuan province of the People’s Republic of China (PRC) were identified and characterized. An analysis of the distribution of rare and trace elements in graptolite schists allowed us to suggest the redox conditions for the formation of high-carbon sediments.

Quality control in geotechnical engineering is becoming an important issue, especially when products are buried underground. Seismoacoustic methods are widely used for investigations in such structures. In this article seismoacoustic well logs from hidden structures (made by jet grouting technology) are being processed with the goal of obtaining additional information about distribution of heterogeneities in improves grounds. Two methods of estimation Q-factor are used: frequency shift method and amplitude ratios method.

At the current level of differentiation of sciences, we could compare achievements of each of them with a quote taken out of context. We know such a procedure holds a high risk, since it could change scientific ideas and meanings fundamentally. In the framework of epistemology, context is the totality of the results of all sciences, i.e. all modern knowledge about the object of study. In the framework of epistemology, context is the totality of the results of all sciences, i.e. all modern knowledge about the object of study; in our case we're talking about knowledge of planet Earth. To some extent mitigate the inevitability of modern sciences separation from this context, the Interdisciplinary Workshop (conference) “Earth Planet System” has been held for 25 years at the Geological Faculty of Lomonosov Moscow State University. In the framework of this Workshop, representatives of numerous sciences and humanities discuss a wide range of problems of life on our planet.