Three-dimensional Earth’s crust density model of the central part of the Golovanevsk suture zone of the Ukrainian Shield

2018 ◽  
Vol 40 (3) ◽  
pp. 27-53
Author(s):  
V. I. Starostenko ◽  
P. Ya. Kuprienko ◽  
I. B. Makarenko ◽  
A. S. Savchenko ◽  
O. V. Legostaeva
Keyword(s):  
Three Dimensional ◽  
Suture Zone ◽  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Density Model ◽  
Earth's Crust

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.

A three-dimensional geophysical model of the Earth’s crust in the central part of the Karelian Craton

2015 ◽  
Vol 463 (2) ◽  
pp. 808-812 ◽  
Author(s):  
I. K. Pashkevich ◽  
A. S. Savchenko ◽  
V. I. Starostenko ◽  
N. V. Sharov
Keyword(s):  
Three Dimensional ◽  
Earth’S Crust ◽  
Karelian Craton ◽  
Geophysical Model ◽  
Earth's Crust

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>

Magnetic model for the earth's crust under the Ukrainian Shield

1977 ◽  
Vol 14 (12) ◽  
pp. 2718-2728 ◽  
Author(s):  
Z. A. Krutikhovskaya ◽  
I. K. Pashkevich
Keyword(s):  
Crustal Thickness ◽  
Earth’S Crust ◽  
Ukrainian Shield ◽  
Maximum Magnetization ◽  
Average Magnetization ◽  
Magnetic Model ◽  
Regional Component ◽  
Earth's Crust ◽  
The Given ◽  
Distribution Of Magnetization

A magnetic model for the crust under the Ukrainian Shield is proposed and the following aspects of its construction are discussed: (1) technique of separation of the regional component of the anomalous magnetic field; (2) estimation of rock magnetization and distribution of the sources of anomalies within the earth's crust; (3) Modelling of the crustal effect with the given distribution of magnetization; and (4) correlation of the regional component with crustal thickness and depth to Curie point isotherm of magnetite.Two ferromagnetic layers are established within the crust. Average magnetization of the upper crust ranges from 0.1 × 10−3 to 0.6 × 10−3 emu for different blocks. Magnetization maximum for the lower crust is 4 × 10−3 emu, the value being supported by different methods.Inhomogeneities with maximum magnetization of 6.5 × 10−3 emu are found within the lower crust.In the areas of regional highs the earth's crust is the thickest, the Moho discontinuity layered, and the distribution of magnetization anomalous for all depths.The stated correlation of regional component with crustal thickness may be of value in predicting the Moho topography.

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