Structure and formation stages of a fault zone in a geomedium layer in strike-slip displacement of the basement

Abstract

The paper reports on numerical modeling of fault structure formation in a geomedium layer under strike-slip displacement of the basement. Consideration is given to structural peculiarities of strain localization zones at different stages of evolution: from nucleation to formation of a main fault. It is found that the localization zones from a rupture in the basement develop as pairs of surfaces similar to oyster valves. It is shown that different types of flower structures can be formed depending on the material properties and layer thickness. One type of flower structures is mostly characterized by Riedel shear surfaces. In another, the initial fracture zones are the surfaces oriented at an angle of ∼40° in the horizontal plane relative to the displacement axis. A main fault forms from top to bottom after the inclined localization zones reach the free surface.