NUMERICAL MODELING OF THE STRESS-STRAIN STATE OF THE YAKUTSK-VILYUI LARGE IGNEOUS PROVINCE FOR THE ANALYSIS OF GEOTECTONIC PROCESSES IN THE SIBERIAN CRATON

Abstract

Stress and strain distributions in the Yakutsk-Vilyui large igneous province (LIP) are numerically simulated under geotectonic extension. A two-dimensional model of the geological structure of a part of the Yakutsk-Vilyui LIP is developed using the geophysical data from the profile “Craton-1980”. However, these geophysical data can only be a source of the geometrical model and elastic properties of Earth’s layers. To describe non-elastic strains during the geological process, the Drucker-Prager-Nikolaevsky model of plasticity is adopted. For elastoplastic analysis of the geotectonic process, the “Jelly Sandwich” shear strength model for the continental lithosphere is used, which is based on the variation of the strength properties with depth. Zones of shear stress concentration and plastic strain localization are observed as a result of the extension in the Lindenskaya basin and Khapchagaiskaya reclamation complying with oil and gas deposit locations in the Yakutia region. Stress components have non-linear distributions determined by the dependence of strength properties on the depth and structural inhomogeneity of continental lithosphere. The pressure distribution obtained in the simulation can partially complement the geological information employed when analyzing the possibility of phase transitions in the rocks in different locations of the studied region.