GORDIENKO V.V., GORDIENKO I.V., DIDENKO L.P. Density distribution in the Earth’s crust and upper mantle of Ukraine

https://doi.org/10.15407/gpimo2025.01.043

V.V. Gordienko, Dr. Sci. (Geol. & Mineral.), Prof., Chief Researcher
e-mail: gordienkovadim39@gmail.com
ORCID 0000-0001-9430-7801
Scopus author Id = 7102473958
I.V. Gordienko, PhD (Geol.), Leading Researcher
e-mail: tectonos1234@igph.kiev.ua
ORCID 0000-0002-5619-0486
Scopus author Id = 5719836183
L.P. Didenko, engineer
e-mail: dlesya345@gmail.com
ORCID 0009-0004-1552-3442
S. I. Subbotin Institute of Geophysics of NAS of Ukraine
32, Palladin ave., Kyiv, 03142, Ukraine

DENSITY DISTRIBUTION IN THE EARTH’S CRUST
AND UPPER MANTLE OF UKRAINE 

The article is devoted to the construction of a three-dimensional density model of the earth’s crust and upper mantle on the territory of Ukraine. Its methodological basis is the scheme of deep processes in the tectonosphere, taking into account, first of all, the results of heat and mass transfer during recent activation. They are superimposed on models of platforms (in addition to the territory of the East European platform, they include Donbass), the Alpine geosyncline of the Carpathians, and the Hercynian-Cimmerian geosyncline of the Scythian plate. The incomplete process of recent activation cannot be accurately described by the geological theory used by the authors. To select a variant of an adequate heat and mass transfer scheme, gravity modeling was previously carried out on a system of profiles around the northern hemisphere with a total length of more than 50.000 km, crossing Eurasia,  North America, the Atlantic and Pacific oceans. The technological scheme most suitable to reality has been identified. It was also applied to Ukraine, where the activated area was determined with greater accuracy than before. This is the first time such a problem has been solved. In the south, the model is limited by the Black Sea depression, at a depth — of 400 km. Densities in the transition zone to the lower mantle were not considered. Test density models are compared with experimental data for mantle platforms. Beyond their limits, the calculated and experimental values of the mantle gravity anomaly are compared. The error (0.01 g/cm3) of the calculation and isodensity cross sections are determined (0.03 g/cm3 for depths from 50 to 400 km; at a depth of 25 km the error is larger, the isoline
cross section is 0.14 g/cm3). Partial melting of upper mantle rocks (at depths of 50—100 km) is not
marked by special anomalies. At a depth of about 400 km, partial melting occurs only under the inactive part of the platform. The differences between the model and the presented one, related to possible
variations in the age of the process and its features at different levels of heat and mass transfer, are
described. The association of mineral deposits with mantle gravitational anomalies and other parameters of the host medium has been outlined.

Keywords: recent activation; deep process; tectonosphere; density model.