The dissertation on competition of a scientific degree of the doctor of geological sciences on a speciality 04.00.22 - geophysics. – Taras Shevchenko National University of Kyiv, Ministry of Education and Science of Ukraine, Kyiv, 2021.
The dissertation presents the results of geological and geophysical study of granitoids of tectonic-magmatic activation (TMA) of the Ukrainian Shield (US), their comparison with similar formations of Central Kazakhstan (CK) and Western Transbaikalia (WTB). The created scheme of typification of conditions of formation of granitoid formations of USh, ZZ and WTB acted as a basis for the further material and physical schemes of comparison and correlation.
Comprehensive analysis of a wide range of material and physical parameters of granitoid complexes of US has allowed to establish a number of features associated with their petrogenesis (conditions of formation, stage of effects of tectonic-magmatic activation, its type and territorial affiliation), rare metal and rare earth specialization.
The bulk density, porosity and elastic waves velocity play a key role in the petrophysical differentiation of granitoids of different stages of TMA USC; for the formations of CK, the factor Q, residual magnetization and thermal are added to this list. The displaced fractured bodies of the TMA of WTB are close to the CK formations in terms of typomorphic petrophysical features, except for magnetic parameters. The porosity and magnitude and type of total radioactivity are effective in distinguishing formations of different stages of TMA; magnetic parameters - to assess the displacement of the magmatic focus; thermal conductivity (for a limited number of cases) and the factor Q - depth.
Methods for calculating the thermodynamic properties of rocks (density, adiabatic bulk modulus, compression, elastic ratio, Gruneisen ratio, etc.) with their subsequent inclusion in petrogenetic classifications, which are based on the quantitative synthesis of actual material and theoretical positions, which allowed to study the properties rocks with their wide variation of physical properties.
The verification base for establishing the conditions for the formation of granitoid rocks of TMA USh has been expanded with the help of a number of geochemical indices (petrochemical polarity coefficient, R/(F + L) ratio, as well as known geodynamic discrimination schemes for acid rocks).
Within the separate petrogeochemical groups of granitoids of the late stages of TMA USh, indicator petrophysical quantities were obtained and the paleogeodynamic conditions of their acquisition of rare metal specialization were reconstructed. A total of 9 typical of TMA USC objects have been identified. With each subsequent stage of TMA, the relative proportion of petrotypes formed under conditions of decompaction is gradually reduced and acquires parity with the rocks formed under conditions of compaction. The formation of the 1st stag) of TMA USC is characterized by insignificant decompression and stress conditions; for the formations of the 2nd stage, a significant range of stresses is reproduced (occupying levels from insignificant compression to tensile stresses) at almost the same level of low decompression; 3rd - moderate indicators of decompression and stress tensile conditions.
The performed mathematical and statistical processing of petrophysical and petrogeochemistry of information provided objectivity in creating a paleogeodynamic model to determine the factors of formation of rare metal specialization of granitoids TMA USH, calculation of "characteristic" search images for metallogenic prediction. The possibilities of the method are given on a series of material-physical models of different details.
