STAGES OF DEFORMATION OF THE UPPER NEOPROTEROZOIC COMPLEXES IN THE NORTHEAST OF THE CENTRAL TAIMYR TECTONOC ZONE

A study has been made of the morphological characteristics of the Upper Proterozoic rocks and their shear sense indicators in the island-arc complex of the northeastern Central Taimyr tectonic zone near the Main Taimyr fault. The structural kinematic studies have made it possible to identify, to characterize and to specify the geodynamic position of the first-stage deformations related by the authors to the Late Neoproterozoic (Ediacaran) orogeny. The first-stage deformation structures are common in the Upper Neoproterozoic metamorphic rocks and represented by the northwest-overturned folds, complex shear zones with C/S structures, and sheath folds indicative of the northwest-trending thrusting. The preserved first-stage deformation structures may be a relic of the suprasubduction accretionary prism formed in the Late Neoproterozoic. The deformations are almost absent in tectonic plates of the upper part of the accretionary prism, being more common in its deeper part. The second-stage (Late Paleozoic) structures are characterized by the east-southeast right-lateral reverse thrust movement along the NE-SW faults and are superimposed on the firststage structures. The third-stage structures, corresponding to the Mesozoic orogeny for the study area, are a local occurrence and have the displacement similar to that of the first deformation stage, though they are represented by brittle left-lateral strike-slip deformations. Besides, at the third stage there is a partial reactivation of the earlier faults.