Structural Styles of Thrust Zones of the Urals and Pay-Khoi Foredeep

Abstract

The article presents an interpretation of geophysical data characterizing the structure of the frontal fold and thrust zones of the Urals and Pay-Khoi, which show the diversity of structural styles of deformations in the study region. The following structural styles of deformations are considered: classical-style thrust zones, which are in-sequence thin-skinned imbrication systems (i); areas of distribution of wedge-shaped allochthons, composed of duplex tectonic plates that are not reflected in the sub-surface layers (ii); inversion zones where faults associated with Ural rifting are transformed into thrust faults (iii); areas whose structure is determined by the deformation of salt diapirs and extrusion of salt (iv); zone, tectonic thickening of the Precambrian complexes overlain by the Paleozoic cover (v). Interpretation of historical and new data on the structure of fold belts makes it possible to significantly update understanding of the structure and development of areas such as zones of wedge-shaped thrusts, areas of development of squeezed salt diapirs, and areas where reactivation and tectonic thickening of Precambrian complexes occurred due to the reactivation of pre-existing faults. New seismic data provided constraints on the magnitude of horizontal displacements in the thrust zones as well as timing of shortening. For the first time they have revealed the development of arrays of small-scale protothrusts.