THE STRUCTURAL ARCHITECTURE OF THE FOOTWALL TO THE MAIN URALIAN FAULT, SOUTHERN URALS

Abstract

The Uralide orogen is a linear collisional belt formed during the Upper Paleozoic as a result of convergence between the East European Craton and outboard terranes, and accretion of intervening island arcs and obduction of oceanic crust onto the East European Craton. This paper presents a new structural subdivision of the southern Urals, to the west of the main suture zone, that puts this part of the mountain belt in a context similar to that of other collisional orogenic belts. This subdivision consists of a west-vergent thrust stack that is made up of an autochthonous to parautochthonous foreland basin, and a parautochthonous foreland thrust and fold belt, flanked to the east by a metamorphic thrust stack. The latter units are structurally overlain by allochthonous rocks of an accretionary complex, slope sediments, oceanic crust and high grade, eclogite-blueschist-bearing, gneiss. Where possible these units are defined on the basis of their internal stratigraphy and structure and on the nature of their bounding faults.