The particularities of the current tectonic structure of the Russian part of the Arctic region are discussed with the division into the Barents–Kara and Laptev–Chukchi continental margins. We demonstrate new geological data for the key structures of the Arctic, which are analyzed with consideration of new geophysical data (gravitational and magnetic), including first seismic tomography models for the Arctic. Special attention is given to the New Siberian Islands block, which includes the De Long Islands, where field work took place in 2011. Based on the analysis of the tectonic structure of key units, of new geological and geophysical information and our paleomagnetic data for these units, we considered a series of paleogeodynamic reconstructions for the arctic structures from Late Precambrian to Late Paleozoic. This paper develops the ideas of L.P. Zonenshain and L.M. Natapov on the Precambrian Arctida paleocontinent. We consider its evolution during the Late Precambrian and the entire Paleozoic and conclude that the blocks that parted in the Late Precambrian (Svalbard, Kara, New Siberian, etc.) formed a Late Paleozoic subcontinent, Arctida II, which again “sutured” the continental masses of Laurentia, Siberia, and Baltica, this time, within Pangea.

The formation of the western margin of the Siberian craton in the Neoproterozoic is considered, with a focus on its transformation from a passive continental margin into an active one, accretion and collision processes, formation of island arcs and ophiolites, orogeny, and continent-marginal rifting. The evolution and correlation of sedimentary basins within fold-thrust belts of the Siberian Platform framing are considered. New structural and kinematic data on the Yenisei fault zone are discussed. On the basis of paleomagnetic data obtained for the structures in the zone of junction of the Siberian Platform and the West Siberian Plate, new models are proposed for the location of the Siberian craton relative to other paleocontinents and microcontinents in the Neoproterzoic. All these data provide a consistent evolution scheme for the western margin of the Siberian paleocontinent in the Neoproterozoic and constrain the position of the Siberian craton margin in Late Neoproterozoic (pre-Vendian) time.

The New Siberian Islands terrane, represented on the Arctic shelf by the archipelagos of the New Siberian Islands and De Long Islands, is one of the key structures of the Arctic. However many...

We present new structural, petrographic, geochemical and geochronological data for the late Paleozoic–early Mesozoic granites and associated igneous rocks of the Taimyr Peninsula. It is demonstrated that large volumes of granites were formed due to the oblique collision of the Kara microcontinent and the Siberian paleocontinent. Based on U-Th-Pb isotope data for zircons, we identify syncollisional (315–282 Ma) and postcollisional (264–248 Ma) varieties, which differ not only in age but also in petrochemical and geochemical features. It is also shown that as the postcollisional magmatism was coming to an end, Siberian plume magmatism manifested in the Kara orogen and was represented by basalts and dolerites of the trap formation (251–249 Ma), but also by differentiated and individual intrusions of monzonites, quartz monzonites and syenites (Early–Middle Triassic) with a mixed crustal-mantle source. We present a geodynamic model for the formation of the Kara orogen and discuss the relationship between collisional and trap magmatism.

There are continuing issues concerning the formation and reconstruction of the geographic position of the Neoproterozoic Yenisei Ridge—a key element of the western framing of the Siberian craton and the Central Asian orogenic belt. This study focuses on the inner structure, composition, and boundaries of the Central Angara terrane, which is the largest in the Transangarian segment of the Yenisei Ridge. We propose a scheme of fault deformation of the region and demonstrate that the fault tectonics of the Central Angara terrane is distinct from that of adjacent terranes. We study in detail the Yeruda pluton granitoids of the Teya complex, which indicate accretionary-collisional magmatic events in this terrane prior to its collision with Siberia. New geochemistry and SHRIMP U–Th–Pb zircon geochronology of the granites indicate that they formed at 880–860 Ma in a collisional setting. Integrated petromagnetic and paleomagnetic investigations yield a paleomagnetic pole that is significantly different from the corresponding Neoproterozoic interval of the apparent polar wander path (APWP) for Siberia. The difference in paleolatitudes between the Central Angara terrane and the Siberian craton at the time of the Teya granites formation was at least 8.6 degrees, which equals a latitudinal separation of at least 1000 km. We consider various possible positions for the terrane relative to the Siberian craton. These results demonstrate that the 880–860 Ma magmatic events in the Central Angara terrane are not related to events in the western margin of the Siberian craton. Therefore, they do not indicate the existence of a Grenville-age orogenic belt in this location, as proposed by some authors.