scholarly journals Seismic Density Model of the White Sea’s Crust

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 492
Author(s):  
Boris Belashev ◽  
Lyubov Bakunovich ◽  
Nikolai Sharov ◽  
Michail Nilov
Keyword(s):  
Gravity Field ◽  
Oil And Gas ◽  
White Sea ◽  
Deep Structure ◽  
Earth’S Crust ◽  
Density Model ◽  
The White Sea ◽  
Software Complex ◽  
Moho Boundary ◽  
Earth's Crust

Study of the deep structure of the White Sea region is relevant to active geodynamics, manifestations of kimberlite magmatism, and the prospects of oil and gas searches. The aim of this work was to model the velocity and density structure of the earth’s crust in the White Sea region. Modelling was carried out using the known data of instrumental observations and the software complex “Integro”. With the help of 2D models based on deep seismic sounding (DSS) profiles and a digital map of the anomalous gravity field, the density structures of local areas of the region’s crust were refined. A 3D density model was built. Within the framework of this model, the positions of the density layers were determined. The relief of the Mohorovichich (Moho or M) discontinuity reflects the anomalies of the gravity field. Depression of the Moho boundary in the bottleneck of the White Sea indicates the vertical structure of the earth’s crust associated with manifestations of kimberlite magmatism.

The deep structure of the earth’s crust beneath the White Sea based on seismic data

2011 ◽  
Vol 66 (3) ◽  
pp. 213-219
Author(s):  
V. B. Piip ◽  
L. P. Tsydypova ◽  
N. V. Shalaeva ◽  
E. A. Teplyakova
Keyword(s):  
Seismic Data ◽  
White Sea ◽  
Deep Structure ◽  
Earth’S Crust ◽  
The White Sea ◽  
Earth's Crust

scholarly journals D magnetic model of the Earth’s crust of the White Sea and adjacent territories

2021 ◽  
Vol 11 (3) ◽  
pp. 375-385
Author(s):  
M.Y. Nilov ◽  
◽  
L.I. Bakunovich ◽  
N.V. Sharov ◽  
B.Z. Belashev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
White Sea ◽  
Sedimentary Cover ◽  
Magnetic Anomalies ◽  
Earth’S Crust ◽  
The White Sea ◽  
Spatial Frequencies ◽  
Magnetic Model ◽  
Earth's Crust ◽  
The Relationship

An important task for the White Sea region, Russia’s second largest diamond-producing province, is the search for magmatic bodies overlapped by sedimentary cover via magnetometer survey. The models, linking local and magnetic anomalies with their sources, are essential for interpretation of search results. The aim of the study is to build a 3D magnetic model of the Earth’s crust for the White Sea region using aeromagnetic data and the modeling technologies of the Integro software package. The simulation is basing on a digital map of the pole-reduced anomalous magnetic field. The sources of magnetic anomalies are believed to be located in the Earth’s crust. The researchers obtained 3D distribution of the relative magnetic susceptibility of rocks by solving the inverse problem of magnetic prospecting. To separate the magnetic sources by spatial frequencies and depth, the model magnetic field was recalculated upward, as well as the TDR derivatives, which determine the lateral boundaries of the sources of positive magnetic field anomalies, were calculated. The researchers further analyzed 2D distributions of the magnetic sources of the model for vertical and horizontal sections with depths of 10, 15 and 20 km, thus proving the relationship between the surface and deep structures of the magnetic sources of the Earth’s crust in the region.

The latest 3D density model of the Barents Sea crust

2021 ◽  
Author(s):  
David Arutyunyan ◽  
Ivan Lygin ◽  
Kirill Kuznetsov ◽  
Tatiana Sokolova ◽  
Tatiana Shirokova ◽  
...  
Keyword(s):  
Gravitational Field ◽  
Gravity Field ◽  
Barents Sea ◽  
Sedimentary Cover ◽  
Three Dimensional ◽  
Density Model ◽  
Potential Fields ◽  
The Barents Sea ◽  
Moho Boundary ◽  
Earth's Crust

<p>The 3D gravity inversion was realized in order to reveal the density features of the Earth's crust the Barents Sea. The original 3D density model of the region includes both lateral and depth density`s changes.<br>The main steps of the modelling are:</p><p>- The calculation of the anomalies of the gravity field in Bouguer reduction with the three-dimensional gravitational effect correction of the seabed.</p><p>- Gravity field correction for the three-dimensional influence of the Moho boundary (according to the GEMMA model). The excess density at the Moho picked by minimizing the standard (root-mean-square) deviation of the gravity effect from GEMMA Moho boundary and Bouguer anomalies. So, the regional density jump at the Moho border is 0.4 g / cm<sup>3</sup>.</p><p>- Based on regional geological and geophysical data about the deep structure of the Barents Sea, it was developed generalized dependence of density changes by depth in the sedimentary cover and the consolidated part of the earth's crust.</p><p>- Compilation of 3D original model of the base of the sedimentary cover on predictive algorithms of neural networks. The neural network was trained on several reference areas located in different parts Barents area using a number of potential fields transformations and the bottom of the sedimentary cover from model SedThick 2.0.</p><p>- Using the resulted dependence of the crust density change by depth and a new model of the sedimentary cover bottom, the gravitational field corrected for the impact of the sedimentary cover with variable density.</p><p>- The finally stripped gravity field is used to create density model above and below the base of the sedimentary cover. Frequency filtering on Poisson wavelets [Kuznetsov et al., 2020] had been used for the final separation of the gravitational field into its components.</p><p>- The inverse task was solved using specialized volumetric regularization [Chepigo, 2020].</p><p>As a result, the crust of the Barents Sea density inhomogeneities were localized by depth and laterally in 3D model, which became the basis for further structural-tectonic mapping.</p><p>References</p><p>Chepigo L.S. GravInv3D [3D density modeling software]. Patent RF, no. 2020615095, 2020. https://en.gravinv.ru/</p><p>Kuznetsov K.M. and Bulychev A.A. GravMagSpectrum3D [Program for spectral analysis of potential fields]. Patent RF, no. 2020619135, 2020.</p>

scholarly journals THREE-DIMENSIONAL DENSITY MODEL OF THE EARTH’S CRUST OF THE TERRITORY OF THE REPUBLIC OF NIGER

2021 ◽  
pp. 6-21
Author(s):  
V.N. Glaznev ◽  
◽  
M.V. Mints ◽  
I.A. Yakuba ◽  
◽  
...  
Keyword(s):  
Gravity Field ◽  
Three Dimensional ◽  
Earth’S Crust ◽  
Density Model ◽  
Weight Functions ◽  
Rift System ◽  
Data Set ◽  
Anomalous Gravity ◽  
The Republic ◽  
Earth's Crust

The paper considers the results of calculation of the three-dimensional density model of the Earth’s crust for the territory of the Republic of Niger in conditions of incomplete initial geological and geophysical information. A brief description of the geological structure of the research region is given and the task of the study is formulated. The initial data set of density modeling is described, including: the anomalous gravity field, the initial model of the medium, the constraints on the desired solution, and the weight functions of redistribution of field incompatibilities. Inversion of the anomalous gravity field was performed in a three-dimensional formulation for a regular grid with a 25×25 km spacing in the plan and 14 layers of irregular vertical grid. The density model of the crystalline crust obtained by solving the inverse problem was combined with a priori data on the density of the upper mantle layer and the previously constructed layered model of the sedimentary cover of the region. The main features of the density model of the Earth’s crust are considered and its density heterogeneities are compared with the regional geological and tectonic data. The leading role of young structures of the West African rift System and their relationship with density inhomogeneities in the lower and middle crust of the territory of the Republic of Niger was noted.

Methodological and technological aspects of exeption of the gravitational effect of the lower part of the earth's crust in study of sedimentary cover of oil and gas-bearing areas

2020 ◽  
pp. 38-45
Author(s):  
V.A. Spiridonov ◽  
◽  
N.N. Pimanova ◽  
Keyword(s):  
Gravitational Field ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
A Priori ◽  
Sedimentary Basins ◽  
Gravitational Effect ◽  
Earth’S Crust ◽  
Density Model ◽  
Crust And Upper Mantle ◽  
Earth's Crust

In the case of seismic density modeling of sedimentary basins, it is necessary to exclude from the observed gravitational field the effect created by inhomogeneities of the lower part of the crustal section. The article offers one of the approaches to the geological field reduction, implemented through the construction of a 3D density model for the entire thickness of the earth's crust and upper mantle. A fragment within the study area is selected from the constructed 3D model and its gravitational effect is calculated. Various options for implementing this approach are considered, depending on the amount of a priori information. The technological base of the method is GIS INTEGRO. Keywords: Gravitational field, geologic reduction, density model, GSS profiles, inversion, structural framework of the model.

scholarly journals Magnetic Structure of the Earth’s Crust in the White Sea Region

2021 ◽  
Vol 12 (11) ◽  
pp. 1007-1020
Author(s):  
Lyubov Bakunovich ◽  
Mikhail Nilov ◽  
Nikolay Sharov ◽  
Boris Belashev
Keyword(s):  
Magnetic Structure ◽  
White Sea ◽  
Earth’S Crust ◽  
The White Sea ◽  
Earth's Crust

scholarly journals Martin Harold Phillips Bott. 12 July 1926—20 October 2018

2019 ◽  
Vol 67 ◽  
pp. 89-117
Author(s):  
Anthony Brian Watts
Keyword(s):  
Oil And Gas ◽  
Deep Structure ◽  
Oil And Gas Industry ◽  
Magnetic Anomalies ◽  
Earth’S Crust ◽  
Field Methods ◽  
Crust And Upper Mantle ◽  
Geological Interpretation ◽  
Gravity And Magnetic ◽  
Earth's Crust

Martin Bott was a geophysicist who made fundamental contributions to our understanding of gravity and magnetic anomalies and their geological interpretation. His research on the deep structure of the Earth's crust was both pioneering and innovative, and he showed how field geophysical measurements could be used to address geological problems such as the mechanics of granite emplacement, sedimentary basin formation and mountain building. When he began his research, the use of gravity and magnetic anomalies to understand deep crustal structure was in its infancy and largely confined to research laboratories in the oil and gas industry. Four decades later his lifetime efforts have seen the emergence of potential field methods as one of the principal means of constraining the structure, stress state and long-term strength of the Earth's crust and upper mantle in continents and oceans. Martin was an inspiring undergraduate teacher and outstanding supervisor, as reflected by his many research students who went on to prominent leadership positions in academia, government and industry. He leaves a legacy of more than 150 scientific papers in peer-reviewed journals and a lucidly written and beautifully illustrated textbook. As well as his many scientific achievements, Martin was an accomplished mountaineer, a dedicated churchgoer and an avid gardener. He saw no conflict between his science and his enduring Christian faith.

scholarly journals Improving of electrical channels for magnetotelluric sounding instrumentation

2015 ◽  
Vol 4 (2) ◽  
pp. 149-154 ◽  
Author(s):  
A. M. Prystai ◽  
V. O. Pronenko
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Deep Structure ◽  
Experimental Tests ◽  
Magnetotelluric Sounding ◽  
Earth’S Crust ◽  
Geomagnetic Variations ◽  
The Earth ◽  
Wide Range ◽  
Earth's Crust

Abstract. The study of the deep structure of the Earth's crust is of great interest for both applied (e.g. mineral exploration) and scientific research. For this the electromagnetic (EM) studies which enable one to construct the distribution of electrical conductivity in the Earth's crust are of great use. The most common method of EM exploration is magnetotelluric sounding (MT). This passive method of research uses a wide range of natural geomagnetic variations as a powerful source of electromagnetic induction in the Earth, producing telluric current variations there. It includes the measurements of variations of natural electric and magnetic fields in orthogonal directions at the surface of the Earth. By this, the measurements of electric fields are much more complicated metrological processes, and, namely, they limit the precision of MT prospecting. This is especially complicated at deep sounding when measurements of long periods are of interest. The increase in the accuracy of the electric field measurement can significantly improve the quality of MT data. Because of this, the development of a new version of an instrument for the measurements of electric fields at MT – both electric field sensors and the electrometer – with higher levels relative to the known instrument parameter level – was initiated. The paper deals with the peculiarities of this development and the results of experimental tests of the new sensors and electrometers included as a unit in the long-period magnetotelluric station LEMI-420 are given.

scholarly journals Deep structure and geodynamic conditions of granitoid magmatism in the Eastern Russia

2020 ◽  
Vol 243 ◽  
pp. 259
Author(s):  
Viktor Alekseev
Keyword(s):  
Deep Structure ◽  
Gravity Anomalies ◽  
Federal District ◽  
Heat Fluxes ◽  
Earth’S Crust ◽  
Granitoid Magmatism ◽  
The Pacific ◽  
Earth's Crust ◽  
Far Eastern ◽  
Eastern Russia

We investigated the deep structure of the lithosphere and the geodynamic conditions of granitoid magmatism in the Eastern Russia within the borders of the Far Eastern Federal District. The relevance of the work is determined by the need to establish the geotectonic and geodynamic conditions of the granitoids petrogenesis and ore genesis in the Russian sector of the Pacific Ore Belt. The purpose of the article is to study the deep structure of the lithosphere and determine the geodynamic conditions of granitoid magmatism in the East of Russia. The author's data on the magmatism of ore regions, regional granitoids correlations, archive and published State Geological Map data, survey mapping, deep seismic sounding of the earth's crust, gravimetric survey, geothermal exploration, and other geophysical data obtained along geotraverses. The magma-controlling concentric geostructures of the region are distinguished and their deep structure is studied. The connection of plume magmatism with deep structures is traced. The chain of concentric geostructures of Eastern Russia controls the trans-regional zone of leucocratization of the earth's crust with a width of more than 1000 km, which includes the Far Eastern zone of Li-F granites. Magmacontrolling concentric geostructures are concentrated in three granitoid provinces: Novosibirsk-Chukotka, Yano-Kolyma, and Sikhote-Alin. The driving force of geodynamic processes and granitoid magmatism was mantle heat fluxes in the reduced zones of the lithospheric slab. The distribution of slab windows along the Pacific mobile belt's strike determines the location of concentric geostructures and the magnitude of granitoid magmatism in the regional provinces. Mantle diapirs are the cores of granitoid ore-magmatic systems. The location of the most important ore regions of the Eastern Russia in concentric geostructures surrounded by annuli of negative gravity anomalies is the most important regional metallogenic pattern reflecting the correlation between ore content and deep structure of the earth's crust.

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