NUMERICAL SIMULATION OF SEDIMENTARY BASIN COMPRESSION AND THRUST STRUCTURES FORMATION
Keywords:
finite-element models, thrust structures, the stress-strain state, the layered medium.Abstract
We investigate dynamic conditions of tectonic compression of sedimentary layers on the basis of 2-D finite-element models, which represent a geotectonic situation (a simplified cross-section) for the Ukrainian Carpathians in Early Cretaceous time. Within the framework of continuum mechanics the numerical model for studying the stressstrain state in the layered medium with essentially non-uniform mechanical properties, different thicknesses of competent and weak layers is used. The non-ideal contact with slipping between layers is taken into account. Series of genetically inherited models, in which the number of thrust faults increases, are constructed and some deformation features and stress distribution are displayed. The occurrence of laterally periodic zones of high stress level control (on the basis of the brittle-fracture criterion) the formation and development of slightly sloping faults through sedimentary layers. Plastic strains modelled by creep for the detachment horizon (lower layers) near to the faults are accumulated and in folded structures are resulted but in the apical parts of thrust block practically are absent.
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