Age and geodynamics of the Irtysh shear zone

Abstract

Purpose. Studying the age and structural relationships of the Irtysh shear zone with the Kalba-Narym zone, determining the age and geodynamic position of crystalline rocks at high temperatures and moderate pressures of the Irtysh shear zone. Methodology. Analysis of literature and stock materials; field research; sample preparation; carrying out isotope studies using SHRIMP-2 and LA-ICP-MS technology; determining small elements by the fusion method using ICP. findings. Detailed geological, petrographic and geochemical studies made it possible to identify three independent metamorphic complexes of the Irtysh shear zone, to determine their age and to establish the geodynamic position of the complexes of the Irtysh shear zone. Originality. The age of the main magmatic and metamorphic complexes developed in the central part of the Irtysh shear zone has been determined; SHRIMP-II, LA-ICP-MS technologies of foreign laboratories have been used; by the results of new dating the geodynamics of the Irtysh shear zone has been corrected. Practical value. From the standpoint of accretion tectonics, using up-to-date isotope dating methods, an attempt has been made to consider the geodynamics of crustal geoblocks ("terrains") and to find continuation of ore levels and ore belts of some terrains in the other ones.