Folded structures of the southeastern and western vergency of the Maksyutov metamorphic complex of the Southern Urals

Abstract

The structural evolution of the Maksyutov metamorphic complex in the southern part of the Uraltau zone (Southern Urals) was investigated. Several stages of deformation were distinguished. The first stage of deformation is associated with the formation of F₁ folds, which include folded structures of the southwestern vergence and sheath folds. The second stage was expressed in the formation of F₂ folds of the southeastern vergence, the most common in the field of development of the Maksyutov metamorphic complex. An alternative model involves the formation of sheath folds as the main structures and folds of the southwestern and southeastern vergence as additional ones under the conditions of tectonic movements in the direction from NE to SW. The choice between the two models requires additional research. The early stages of the deformation history of the complex are associated with the exhumation of its rocks from the subduction zone of the Magnitogorsk island arc. The next stage was expressed in the formation of F₃ folds of the western vergence associated with movements along the Main Ural Fault zone, during the Late Paleozoic collision. Post-collision shear movements marked by F₄ folds with steeply dipping hinges completed the main stage of the region’s structural evolution.

Keywords:

Uraltau zone, structural evolution, deformation stage, asymmetric folds, sheath folds, hinge, lineation, Maksyutov metamorphic complex, vergence