In February 2014, the Institute of the Earth’s Crust of Siberian Branch of the Russian Academy of Sciences celebrated its 65th anniversary. As of 01 January 2014, there are 300 employees in its staff, including one Full Member of RAS, one Corresponding Member of RAS, 27 Doctors and 74 Candidates of Sciences. Postgraduate courses are taken by 33 young researchers. The Institute has 13 laboratories and the Analytical Centre to research recent endo- and exogeodynamics, geological environment and seismicity, mineral resources, underground water dynamics and geoecology, internal structure, paleogeodynamics, endogenic processes and fluid dynamics of the continental lithosphere.

 

From 2009 to 2013, the Institute has published 775 scientific papers in Russia and abroad, implemented 145 projects supported by grants from the Russian Foundation for Basic Research, 21 projects under the Fundamental Research Program of the RAS Presidium and the Earth Sciences Section of RAS, 27 integration projects of SB RAS, and 22 programs of fundamental studies of RAS. The Institute fulfilled more than 50 scientific research contracts with industrial companies in Siberia and several state contracts with governments of the RF regions. Educational research, science organization and international activities are successfully implemented. Renovation and retrofit replacement of equipment, instruments and tools is ensured.

 

A fitting testimony to scientific achievements of IEC SB RAS is that it ranks among leading research institutes in the Earth sciences in Russia and abroad, as confirmed by all the RAS performance indicators.

 

 

The article reviews the history, main scientific fields and major results of the studies performed by the Laboratory of Petrology, Geochemistry and Ore Genesis and the Laboratory of Geology and Magmatism of Ancient Platforms.

 

 

The deep structure and paleogeodynamics of the Siberian craton and the Central Asian folded belt are studied by two specialized laboratories of the Institute of the Earth’s Crust, SB RAS – the Laboratory of Complex Geophysics and the Laboratory of Paleogeodynamics. A variety of modern geophysical methods is applied. Surface wave tomography is focused on determination of 3D velocity structure of the upper mantle. Seismic, gravimetric and electrical surveys are aimed at stu­dies of structures of the crust and the upper mantle. Geothermic parameters of the lithosphere in Central Asia are measured. In search for mineral resources, new geophysical prospecting technologies are developed. Quality paleogeodynamics reconstructions require a proper understanding of the structural evolution of the Siberian craton and the Central Asian folded belt. Researches in this scientific field are conducted by the Laboratory of Paleogeodynamics. Besides, the Laboratory studies new minerals and conditions of their formation. Some of the scientific research projects are jointly implemented by the two laboratories, and research results are regularly published in Russia and abroad.

 

 

Based on comparative analyses of spatial and temporal patterns of high- and medium-potassic basaltic eruptions in the Central Mongolia and marine survey records of Sr isotopes, it is revealed that the start of the recent geodynamic stage in the Central Mongolia correlates with the starting point of its global manifestation, which gives an evidence of a close relationship between magmatic occurrences in the region under study and processes of global convergence. The magmatic occurrences are considered as representing the recent geodynamic evolution of the past 90 Ma with milestones of ~66, 40–37, ~32 and 17–15 Ma ago. Global changes, except those ~32 Ma ago, are shown in marine records of Sr isotopes. The Late Plestocene – Holocene natural and climate setting is reconstructed from radiocarbon datings of various geological and paleobiological objects. Changes of the natural environment and climate of the Northern hemisphere are plotted with account of strong magma eruptions, attacks of asteroids and meteorites, changes of lithological compositions of sedimentary complexes and species compositions of fauna at the given time interval.

 

 

 The article presents the information on organizing the studies of chemical and mineral compositions of rocks at the Analytical Centre of the Institute of the Earth's Crust, SB. It describes its main scientific fields and capabilities of laboratory equipment available in the Centre to study rock samples. The past major scientific achievements are given in brief. Scientific results from 2009 to 2013 are presented in a more detail, and a corresponding list of publications is included.

 

 The article describes the history, the staff, researches and scientific activities of the Laboratory of Tectonophysics of the Institute of the Earth’s Crust, which are focused on problems of faulting in the lithosphere. The Laboratory was established 35 years ago. The article reviews the major results of scientific research projects implemented from 2009 to 2013. The main objects of the complete cycle of tectonophysical studies were the zone-block structure of the lithosphere in the Central Asia, fault tectonics, stress fields, mechanisms of formation and seismicity of the Baikal rift zone, emanation activity of crustal faults, regimes of displacements at fault segments etc. It is shown that the team of the Laboratory views its scientific prospects in development of comprehensive models of inter-block zone of destruction, taking into account regular fault patterns and regularities of accompanying processes (such as seismic, emanation and other types of activity) which are predetermined by such fault patterns.

 

 

 

The article presents recent results of seismogeological, seismological and engineering seismological studies conducted by the Laboratory. Specific features of seismicity in regions of Russia are reviewed. Space-and-time and energy patterns of seismicity and the state of stresses of the lithosphere are analysed. It is forecasted how foundations of buildings and structures located in the Baikal rift zone may be affected by potential strong earthquakes.

 

 

Studies of recent geodynamics have been conducted by the Institute of the Earth’s Crust, SB RAS since 1998. Present-day crustal deformations are monitored at the geodynamic GPS polygon established by the Laboratory of Recent Geodynamics in the Mongol-Baikal region. Original methods and techniques using specialized equipment are applied to research intra-continental tectonic deformation and have already provided original scientific results. Independent data are received concerning the onset and character of processes of neotectonic activation and the state of stresses and deformation of the crust in the southern part of Siberia and in Mongolia. A model of the Late Cenozoic and contemporary geodynamics of the Mongol-Siberian mobile area is proposed. With application of GPS geodesy methods, quantitative parameters of present-day horizontal movements and deformations are determined for Central Asia and a part of the Far East at different scale levels. Present-day velocities of extension of the Baikal rift are estimated, and parameters of rotation of the Amur plate relative to Eurasia are calculated. Data on long-term and contemporary deformation are subject to comparative analyses. The Laboratory develops studies of present-day and historical seismicity in relation to processes of contemporary faulting in active tectonic zones of inter-plate boundaries and diffusive activation of subactive intraplate territories. The first results are obtained in studies of local crustal deformation by methods of satellite radar interferometry and ground polygonometry. Jointly with other institutes of SB RAS, the Laboratory conducts instrumental studies of interaction between the lithosphere and the ionosphere. Looking further ahead, the main scientific fields and prospects of the Laboratory are highlighted.

 

 

 The article reviews problems of regional seismic safety and current programs aimed at earthquake proofing of buildings, houses, facilities and life-support systems. It describes the main scientific methodological principles for certification of buildings and facilities located in earthquake-prone regions. With reference to case studies of Angarsk, Shelekhov and Baikalsk and data on Ulaan Baatar (jointly studied with ICAG of the Academy of Sciences of Mongolia), examples of the certification method application in practice are described. Special attention is given to monitoring of the technical status of bearing-wall apartment buildings and houses built in 1960s and 1970s. Cooperation between the Laboratory of Earthquake-Proof Construction and leading scientific research institutes of Russia is reviewed specifically within the framework of the Federal Seismic Safety Program and participation of the Laboratory in development of the national standard titled GOST R Earthquake Intensity Scale.

 

 

 The article informs about the history, the staff, researches and scientific activities of the Laboratory of Hydrogeo­logy and the Laboratory of Engineering Geology and Geoecology of the Institute of the Earth’s Crust, SB RAS. It reviews the major results of scientific research projects implemented from 2009 to 2013, which provided for determination of characteristics of the geological medium and hydrosphere of East Siberia and Mongolia in natural and technogenic conditions and mo­deling of the evolution of natural, natural-technogenic hydrogeological and engineering geological systems in regions with contrasting climate conditions and specific geological settings.

 

 

In the past five years, the Institute of the Earth’s Crust Museum has considerably increased its exhibition space and the collection of objects. The Museum documents the history of the Institute since 1949. Its three rooms contain original artefacts, books and reports by prominent scientists and a rich variety of rocks collected by IEC staff, including a collection of new minerals discovered by IEC researchers and approved by the Commission for New Minerals Nomenclature and Classification (CNMNC) of the International Mineralogical Association. Displayed are a unique collection of kimberlites from Yakutia which was given to the Museum by D.I. Savrasov, a founder of the Kimberlites Museum in the city of Mirny, Republic of Sakha (Yakutia), a collection of hydrogenous minerals from many countries of the world which was given to the Museum by Dr. B.I. Pisarsky, a set of minerals collected by Dr. Yu.V. Komarov who founded the Museum and given to the Museum by his widow L.V. Komarova, and other sets of minerals. A special exhibition is devoted to the 100th Anniversary of Prof. M.M. Odintsov, Corresponding Member of the USSR Academy of Sciences, who was a prominent Russian geologist, worked in Siberia and headed the IEC from 1954 to 1976. To commemorate the 90th Anniversary of the Museum founder Dr. Yu.V. Komarov, the first museum room was renovated and now includes an exhibition devoted to researches of Dr. Yu.V. Komarov. A new display is a collection of minerals from Bulgaria. The Museum is regularly visited by high school and post graduate students to whom the museum objects and collections of minerals serve as useful physical materials in studies of geology and mineralogy, and in such cases the Institute of the Earth’s Crust Museum operates as an educational outreach.

 

 

 

The article provides data on the structure of the Paleoproterozoic intercontinental Imandra-Varzuga rifting structure (IVS) and compositions of intrusive formations typical of the early stage of the IVS development and associated mineral resources. IVS is located in the central part of the Kola region. Its length is about 350 km, and its width varies from 10 km at the flanks to 50 km in the central part. IVS contains an association of the sedimentary-volcanic, intrusive and dyke complexes. It is a part of a large igneous Paleoproterozoic province of the Fennoscandian Shield spreading for a huge area (about 1 million km2), which probably reflects the settings of the head part of the mantle plume. Two age groups of layered intrusions were associated with the initial stage of the IVS development. The layered intrusions of the Fedorovo-Pansky and Monchegorsk complexes (about 2.50 Ga) are confined to the northern flank and the western closure of IVS, while intrusions of the Imandra complex (about 2.45 Ga) are located at the southern flank of IVS. Intrusions of older complexes are composed of rock series from dunite to gabbro and anorthosites (Monchegorsk complex) and from orthopyroxenite to gabbro and anorthosites (Fedorovo-Pansky complex). Some intrusions of this complexes reveal features of multiphase ones. The younger Imandra complex intrusions (about 2.45 Ga) are stratified from orthopyroxenite to ferrogabbro. Their important feature is comagmatical connection with volcanites. All the intrusive complexes have the boninite-like mantle origin enriched by lithophyle components. Rocks of these two complexеs with different age have specific geochemical characteristics. In the rocks of the Monchegorsk and Fedorovo-Pansky complexes, the accumulation of REE clearly depends on the basicity of the rocks, the spectrum of REE is non-fractionated and ‘flat’, and the Eu positive anomaly is slightly manifested. In the rocks of the Imandra complex, the level of REE accumulation is relatively higher. The spectrum of REE here differs with more fractionated LREE with a ‘flat’ distribution of HREE and distinct Eu anomalies. Rocks of all the intrusive complexes are characterized mostly by negative eNd(T) values, and eNd values are distributed more heterogeneously in the rocks of the Monchegorsk complex than in the rocks of the Fedorovo-Pansky complex. Deposits and occurrences of Cr, complex PGE-Cu-Ni and low-sulfide Pt-Pd ores of the world class are spatially related and genetically associated with the IVS intrusive complexes. The Sopcheozero deposit (Monchepluton of the Monchegorsk complex) and Bolshaya Varaka deposit (the same-name intrusion of the Imandra complex) represent a layered Cr mineralization. Complex PGE-Cu-Ni deposits are confined to Monchepluton. They occur in vein ores of the Nittis-Kumuzhya-Travyanaya massifs (which have been worked out) and Sopcha, vein PGE-Cu, injecting Ni ores mostly and bottom deposits of the Nittis-Kumuzhya-Travyanaya massifs, as well as in the Nyud ‘critical’ horizon. In the past 10–15 years, low-sulphide Pt-Pd ores were discovered as new for the Kola region. Two main types of such ores have been distinguished: (1) stratiform (rift) ores being consistent with the massifs’ layering, and (2) basal ores located within lower marginal zones. Deposits of Kievey (West-Pansky massif of the Fedorovo-Pansky complex), horizon 330 of the Sopcha and Vurechuayvench (Monchepluton of the Monchegorsk complex) belong to the first type; the second type is represented by the Fedorovotundrovskoe (Fedorovo-Pansky complex), South Sopcha and Loypishnyun (Mon­chetundrovsky massif of Monchegorsk complex) deposits.

 

 

 

 The publication presents results of the study aimed at reconstruction of recent crustal stresses for Central and South-Eastern Asia with application of the method of cataclastic analysis of displacements caused by ruptures, which was proposed by Yu.L. Rebetsky. Two sources of seismic data were referred to: (1) the catalog comprising data from publications covering the period from 1904 to 1992, and (2) the Global Centroid Moment Tensor (CMT) Database of earthquake mechanisms (http://earthquake.usgs.gov/eqarchives/sopor), which covers the period from 1978 to 2010. The method of cataclastic analysis in its earliest version was applied in 1996 and 1997 when seismic data from the first catalog were analyzed, and it yielded only parameters of stress ellipsoids; the reconstructions were published in a Russian-Chinese journal (it does not exist now). In this paper, these reconstructions are presented in new graphical formats of GIS. Data from the Global CMT Database were analyzed by the method of cataclastic analysis in the new revision with application of its stages 1 and 2. Based on the calculations, orientations of axes of principal stresses, types of ellipsoids, correlations between spherical and deviatoric components of stress tensors, and reduced stresses were determined. The two sets of reconstructions are compared in this paper. The catalog of earthquake focal mechanisms for the period from 1904 to 1992 consolidated information provided by different authors, and thus focal data for many seismic events were highly inconsistent; therefore, the reliability of reconstructions based on such data seems to be lower than that on the basis the Global CMT Database for the period from 1978 to 2010. Some of the reconstructed stress tensor parameters are mapped. For the areas which data are given in the Global CMT Database and considered as more reliable, mapping is based on stress parameters calculated from such data. For the areas that are not covered by the Global CMT Database, reconstructions based on the first catalog are mapped. In the maps showing consolidated patterns of the state of stresses, spacious areas of horizontal extension of the crust in Tibet are clearly identified. In the south, such areas are bordered by regions of horizontal compression of the crust in Himalaya; in the north and north-east, they are bordered by regions of horizontal shear of the crust in East Kunlun. According to results of calculations at stage 2 of the method of cataclastic analyses, the crust in the central part of Tibet is subject to intensive confining pressure and lateral compression that is reduced in the neighboring regions. The crust in the southern and northern parts of Pamir is also subject to horizontal extension and shear. Regions of horizontal compression are located to the north, west and south of Pamir. Regulations of the field of recent tectonic stresses of Tibet and Pamir, which are revealed in this study, can be explained by the concept of ‘tectonic spreading’ of these regions due to gravity, which causes intensive horizontal spreading of the crust in Himalaya when the southern boundary of Tibet bends outwards and spreads over the Indian ‘indenter’ moving in the north–north-eastern direction. It is suggested by the data on horizontal extension of the crust in Tibet and underthrusting shear stresses over the horizontal zones that the impact Indian ‘indenter’ does not go beyond the crust of Pamir and the crust of the central parts of Tibet which is located above the long-term active mantle plume.

 

 

 

Structural-paragenetic and kinematic methods of tectonophysics are applied to study earthquake focal mechanisms of the Zagros system. Nodal planes of focal mechanisms are identified as L-, L′- and R-, R′-shears by the first method, whereby coordinates of principal stress axes P, T and N (i.e. in tectonophysics, σ1, σ3 and σ2, if σ1 ≥ σ2 ≥ σ3) are defined. ‘Working’ nodal planes corresponding to activated ruptures are revealed. Axes of the main normal stresses are combined into local groups on the basis of the kinematic identity of planes of seismogenic ruptures (Figure 2). The second method is applied to construct stereograms of the main axes P, T and N, to construct and interpret stereograms of vectors of seismogenic shifts (Figure 3), and to more clearly define coordinates of principal axes σ1, σ3 и σ2. As evidenced by their comparison, coordinates of the principal axes obtained by the two tectonophysical methods are well coincident (see Figure 2). Five groups of seismogenesis are distinguished; they differ in combination of deformation regimes and kinematic conditions. Locations are determined of the areas wherein earthquake foci of similar parameters are located. This means that seismogenic zones are distinguished; structural and kinematic characteristics of such zones are determined by parameters of stereographic models of corresponding types of seismogenesis (Figures 4 and 5). It is established that the region is dominated by shear and upthrust deformation regimes due to regional submeridional compression and SW-NE compression (see Figures 4 and 5). Submeridional subhorizontal compression is explained by the northward movement of the Arabian plate, and SW-NE compression is explained by divergent processes within the limits of the Red Sea rift. The time pattern of the seismogenic processes from 1979 to 2001 shows that submeridional compression and SW-NE compression are associated with different deep mechanisms. Processes of SE-NW compression, which are observed in the northern part of the Arabian plate, are caused by its interaction with the Eastern Black Sea microplate.

 

 

 

 Gravity phenomena related to the Earth movements in the Solar System and through the Galaxy are reviewed. Such movements are manifested by geological processes on the Earth and correlate with geophysical fields of the Earth. It is concluded that geodynamic processes and the gravity phenomena (including those of cosmic nature) are related.  

The state of the geomedium composed of blocks is determined by stresses with force moment and by slow rotational waves that are considered as a new type of movements [Vikulin, 2008, 2010]. It is shown that the geomedium has typical rheid properties [Carey, 1954], specifically an ability to flow while being in the solid state [Leonov, 2008]. Within the framework of the rotational model with a symmetric stress tensor, which is developed by the authors [Vikulin, Ivanchin, 1998; Vikulin et al., 2012a, 2013], such movement of the geomedium may explain the energy-saturated state of the geomedium and a possibility of its movements in the form of vortex geological structures [Lee, 1928]. The article discusses the gravity wave detection method based on the concept of interactions between gravity waves and crustal blocks [Braginsky et al., 1985]. It is concluded that gravity waves can be recorded by the proposed technique that detects slow rotational waves. It is shown that geo-gravitational movements can be described by both the concept of potential with account of gravitational energy of bodies [Kondratyev, 2003] and the nonlinear physical acoustics [Gurbatov et al., 2008]. Based on the combined description of geophysical and gravitational wave movements, the authors suggest a hypothesis about the nature of spin, i.e. own moment as a demonstration of the space-time ‘vortex’ properties.

 

 

  The 9th International Workshop “Physics and Forecasting of Rock Destruction” was held in the Institute of the Earth’s Crust, SB RAS, in Irkutsk on 02–06 September 2013. The article reviews the main events of this scientific forum and briefly describes its discussion results concerning prediction / forecasting of dynamic destruction of rocks due to loading in various regimes and scales. Also reviewed are options for improvement of forecast methods and their application to practice.