Magmatism and Tectonophysical Characteristics of Formation of Ore-Bearing Intrusions in the Norilsk Region (Eastern Siberia, Russia)

The specific features of the field of deep intrusions and tectonics of the NR are studied. It is shown that the formation of copper–nickel deposits in the study area in the Early Triassic is associated with the evolution of the stress field in the crust over 50‒100 Ma. It is established that the specific features of the formation of the intrusive field at the initial stage are associated with the deep and lateral heterogeneity of the stress state that arose before the onset of magmatism in the Early Permian in the crust of the Khantay‒Rybninsky uplift and adjacent structures. The emergence of this heterogeneity, which has an inherited long-term nature, is due to the formation of uplifts (swells) in the region and the processes of denudation of the surface of these uplifts (amplitudes of 1.5‒2.5 km). Since the processes of surface denudation lead to the release of rocks that have experienced a supercritical flow at great depths, in the upper part and, partially, in the middle part of the crystalline crust of the Khantay‒Rybninsky uplift and adjacent territories there were prerequisites for the emergence of a stress state of horizontal compression. In the lower part of the crust of the Khantay‒Rybninsky uplift, as well as in the crust of the Norilsk‒Kharaelakh trough and the Tunguska syneclise, the horizontal extension regime was preserved. This difference in the stress state of the crust determined the specific features of the spatial heterogeneity of the development of volcanism and intracrustal magmatism of the Norilsk‒Kharaelakh trough and Tunguska syneclise.