Estimation of biogenic substance transport by water masses in Tatar Strait

The conditions of transformations of biogenic substances and the redistribution of their concentrations in the shelf water of Sakhalin Island are studied. Preliminary works have given the results for the water area of La Perouse Strait and Aniva Bay (the Sea of Okhotsk), while this paper gives such results for Tatar Strait (the Sea of Japan). Three electronic instruments of oceanographic studies are applied: an adapted version of Bergen Oceanic Model (for the reconstruction of the space and time distribution of seawater temperature, salinity, and density; the circulation intensity of water masses; and water exchange parameters with nearby water areas and within the strait); GIS “Sakhalin Shelf” (for the reconstruction of annual variations in thermohaline characteristics on a standard grid and horizons of oceanographic stations, and the parameters of the aquatic environment); hydroecological CNPSi-model (for studying the annual dynamics of biogenic element compounds, the biomasses, biohydrochemical activity and bioproduction of microorganisms—bacteria, phytoplankton, and zooplankton, taking part in transformation of biogenic substances and petroleum hydrocarbons, as well as the internal fluxes of biogenic substances governed by the activity of microorganisms and the external load on the marine ecosystem). The results of modeling the spatial transport of biogenic substances through the outer boundaries of Tatar Strait water area and the boundaries of the three areas identified within it are presented and discussed.     

Pool Structures: A New Type of Interaction Zones of Lithospheric Plate Flows

Study of tectono-geodynamic clusters of the continental lithosphere (the Sloboda cluster of the East European Platform and the Pamir cluster of Central Asia) permitted identification of pool structures, which are a specific type of zone of intraplate interaction of rock masses.     

Trigger effects in the evolution of geological structures as applied to regional tectonics

In the course of reconstructing the geodynamic evolution of certain regions and structures, it is pointed out that the formation algorithm, which operates for a long time, abruptly changes unaffected by any obvious factor: a thermal event, collision of lithospheric plates, etc. It is suggested that the sharp change in the geological evolution algorithm is related to accumulation of the energy potential, the relaxation of which is initiated by a trigger mechanism that leads to realization of the stored energy in a new form. Several geodynamic situations, the origin and development of which are related to the trigger mechanism, are considered in the paper: morphostructural subdivision of paleobasins, interaction of deformation and metamorphism, vertical accretion of a granitic-metamorphic layer, and development of horizontal protrusions (plate flows) in the Earth’s lithosphere.     

Polygenic nature of granite clastites: Communication 1. Exogenic and tectonic postmagmatic disintegration of granite massifs

Disintegrated granitoids, which frequently enclose abundant clastic material of the same rocks, are widespread in the upper parts of the Earth’s crust. They occur both on the surface and under the thick sedimentary cover. Two processes are responsible for the formation of such rocks: supergenic (chemical and physical weathering) and tectonic (prototectonics and posthumous disintegration). These processes result in the formation of similar (in compositions, textures, and attitude) clastic rocks, which complicates the interpretation of their genesis in particular situations. In this work, we discuss processes of the exogenic and tectonic disintegration of granitoids, structure of disintegrated rocks, and mineral transformations. Typomorphic features of the disintegrated granitoids related to tectonic and exogenic processes are compared.     

Granitic protrusions in the structure of intraplate reactivation,southern Mongolia

The paper describes tectonic assemblies determining structure and kinematics of the plate evolution in the eastern segment of the Gobi Altay and Gobi Tien Shan intraplate reactivation zones in southern Mongolia. These zones are characterized by deformations corresponding to a 3D brittle-ductile shear flow. The structural and compositional reworking is most strikingly expressed in certain varieties of granites, which form specific geostructures called crystalline protrusions. The internal structure of protrusive bodies is distinguished by fragmentation differing in scale, intense brecciation, cataclasis, and structural-mineral reworking of rocks. Taken together, these phenomena facilitate the tectonic mobility of rock masses under low-temperature and hypabyssal conditions and maintain 3D tectonic flow in basement rocks. The tectonic style of the region and its evolution are predetermined by the 3D flow of granitoids in the crystalline basement, which is related to the joint action of various mechanisms discussed in this paper.     

Study of space debris burning in Earth’s atmosphere via television meteor monitoring

The observations on ground-based facilities miss multitudes of small fragments of space debris. However, the intrusion of fine particles into the atmosphere and their subsequent burning can be observed along with the usual meteor phenomena. Since the solar system meteoric body velocities at the entry into the atmosphere are over 11.2 km/s, and the velocity of the space debris objects does not exceed 11.2 km/s, the selection of meteors by velocity is a reliable criterion for separating these bodies. The paper describes a method of selecting the space debris fragments using a technique of television meteor monitoring. The technique was adapted on the material of real television observations on the FAVOR wide-field monitoring camera with high temporal resolution, conducted in 2006 in the Arkhyz station of the Institute for Precision Instrumentation (North Caucasus).     

History of the Cartography and Toponymy of the Valley of Geysers (Kronotsky Reserve,Kamchatka Peninsula,Russia): From Field Drawings to 3D Documents

The article describes the evolution of the cartography and toponymy of the second largest geyser field in the world – the Valley of Geysers in the Kronotsky Reserve (Kamchatka Peninsula, Russia), discovered in 1941. The toponymy evolved in close connection with the development of the cartographic base that passed through the three stages from the first manual drawings to large-scale maps and to 3D models of the territory. The number of geysers with personal names increased gradually from twelve to more than one hundred. The article presents examples of diagrams and maps as well as tables of thermal features with coordinates. All main sources of literature were analysed for the period of 1941–2017, and the article presents a comprehensive historiography on the investigated topic. The evolution of instruments for the measurement of geyser activity is also briefly overviewed with examples of data obtained using the different methods.     

Finding of the Ediacaran-Vendian fossils in the Far Taiga Deposits, Patom highlands

The first finding of prints of the Vendian Beltanelloides sorichevae Sokolov 1965 in the lower part of the Barakun Formation confirms the Vendian age of the Far Taiga Group, Patom Complex. This finding also raises a problem concerning the lower propagation limit of Beltanelloides sorichevae.     

Transverse geochemical zonality: The Karymskii Volcanic Center

Variation in the geochemical characteristics of basalts has been found within the Karymskii Volcanic Center (KVC). The concentrations of potassium, titanium, phosphorus, large-cation, high-charge, rare and rare-earth elements increase from the frontal zone (Pribrezhnyi Yuzhnyi, Stena, Paleo-Semyachik and Malyi Semyachik, and Ditmara volcanoes) toward the backarc zone (Odnobokii, Pra-Karymskii, and Akademii Nauk volcanoes). High ratios of fluid-mobile elements to non-mobile ones in the basalts of the frontal zone provide evidence of low-temperature aqueous fluids being involved in magma generation, with these fluids separating from the subducted oceanic plate at low pressures. The backarc zone typically shows higher Th/Nd and Th/Yb ratios, suggesting high-temperature fluids that take part in magma generation with increasing depth (and increasing temperature) as far down as the top of the subducted plate. The variation in the geochemical characteristics of the KVC basalts from the frontal to the backarc zone is less pronounced than that in the lavas of Mutnovskii and Gorelyi volcanoes in southern Kamchatka. These differences may be related to the geodynamic parameters of the subduction zone in the East Kamchatka and the South Kamchatka segments of the Kamchatka island arc, primarily to the dip angle of the Benioff zone, the distance to the trench axis, the subduction age, and possibly to heterogeneities in the mantle wedge beneath the KVC.     

The Karymskii Volcanic Center: Volcanic rock geochemistry

This paper is concerned with the petrology and geochemistry of rocks found in the Karymskii Volcanic Center (KVC), which is the largest volcanic center in the Eastern volcanic belt of Kamchatka. The KVC has been built in a rhythmic manner since the Late Pliocene, forming successive differentiated rock complexes. The pattern of variation for major and minor elements in the KVC volcanic rocks can be explained by the fractionation of mineral phases from the parent melt. The process involved enrichment of the residual melts with alkalis and lithophile elements (Rb, Ba, Sr, Pb, Th, U, REE), as well as depletion in coherent elements (Ni, Cr, Sc, Ti). A geochemical study of the KVC volcanic rocks shows that these are typical island arc formations. The relationships between incompatible elements suggest a two-component magma generation system: a depleted mantle source (N-MORB) and suprasubduction fluids (an island arc component). The melt may have been contaminated by a metasomatically altered substratum in the top of the intermediate chamber with added crystalline cumulus phases (and melts) of the earlier magma generation phases in the KVC.