Concerning tectonics and the tectonic evolution of the Arctic
Transcription
Concerning tectonics and the tectonic evolution of the Arctic
Available online at www.sciencedirect.com ScienceDirect Russian Geology and Geophysics 54 (2013) 838–858 www.elsevier.com/locate/rgg Concerning tectonics and the tectonic evolution of the Arctic 1 V.A. Vernikovsky *, N.L. Dobretsov, D.V. Metelkin, N.Yu. Matushkin, I.Yu. Koulakov A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia Received 13 March 2013; accepted 10 April 2013 Abstract 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. © 2013, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved. Keywords: tectonics; geodynamics; rifting; subduction; accretionary-collisional belt; paleomagnetism; paleoreconstruction; seismic tomography; Arctic Introduction The youngest ocean on the planet—the Arctic Ocean is of great interest from a scientific as well as from a practical point of view. Investigations of Russian and foreign authors show that knowledge of the geologic structure, formation and evolution of this ocean, can help in solving many important regional issues, including those concerning the formation of oil and gas sedimentary basin. These attainments also allow us to understand the relationship between continental margins, including the shelves, and the various units, characterized by a continental structure of the crust, but at the moment located rather far from the continents. The answers to these questions are undoubtedly necessary in determining the location of the outer border of the continental shelf for Russia as well as other states with an Arctic coast (Laverov et al., 2013). The modern structure of the Arctic Ocean is determined by the position of two of the largest basins: the Amerasian (Canada) basin, for which the time and character of spreading 1 The article was translated by the authors. * Corresponding author. E-mail address: [email protected] (V.A. Vernikovsky) processes are under discussion and the Eurasian basin with a modern spreading center in the form of the middle-oceanic Gakkel Ridge (Fig. 1). The formation of the former is linked to the detachment of the Chukchi–Alaska block from the North-American margin at the Jurassic–Cretaceous boundary, and the latter—with the detachment of the Lomonosov Ridge and possibly the Alpha–Mendeleev Ridge from the Barents– Kara margin. It was these tectonic motions, as well as the relative position of the Eurasian and North American continents that determined its structure in the last 150 m.y. (Fig. 2). Fig. 1 shows the structure of the oceanic basins and their framing as well as the structure of the shelf and continental parts. On the other hand, Fig. 2 shows a tectonic map of the Arctic depicting the main structural elements of fold belts and continental blocks and their division by age, crust type and basement age. This allows us to determine the Timan–Pechora, Svalbard, Kara, Novaya Zemlya microplates, the New Siberian island and De Long archipelagos continental block, the Chukchi microcontinent, as well as continental terranes in the ocean, represented by the Lomonosov, Mendeleev Ridges and other blocks. During the determination and representation of the entire structure of the East Arctic the following tectonic 1068-7971/$ - see front matter D 201 3, V.S. So bolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.rgg.201 + 3.07.006 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 839 Fig. 1. The main geomorphologic structures of the Arctic Ocean (http://www.ngdc.noaa.gov/mgg/bathymetry/arctic/currentmap.html). The framed area represents the region of Fig. 2. 1, faults and lineaments, definite and inferred; 2, thrusts; 3, mid-oceanic ridge axis; 4, Okhotsk–Chukchi volcanic-plutonic belt. maps were used: (Bognanov and Khain, 1996, 1998; Khain et al., 2011). Therefore, this paper discusses the particularities of the modern tectonic structure of the Russian part of the Arctic region with division into the Barents–Kara and Laptev–Chukchi continental margins; also new geophysical data (Gaina et al., 2010, 2011; Glebovsky et al., 2013), including the first seismic tomography models for the Arctic (Jakovlev et al., 2012). Based on the analysis of the tectonic structure of key units, our own paleomagnetic data for these units and new geologic and geophysical information we consider a series of paleogeodynamic reconstructions for the arctic structures from the Neoproterozoic to the end of the Paleozoic. Based on these reconstructions we consider important and complicated issues of the tectonic structure and geodynamics of the Central and Eastern Arctic, related to the evolution of the Arctic Ocean 840 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 841 Fig. 2. The map of the main tectonic and geomorphologic elements of the Arctic. The map was composed using publications: (Bogdanov and Khain, 1996, 1998; Grantz et al., 2009; Khain et al., 2011; Shipilov and Vernikovsky, 2010). The frame shows the contour of Fig. 3. 1, young plates cover; 2, modern continental slope; 3, riftogenic and syn-strike-slip basins Mz–Cz; 4, fragments of Caledonian orogenic belts; 5, troughs and slopes with intermediate type crust; 6, accretionary-collisional complexes; 7, oceanic crust; 8, blocks and ridges with continental crust; 9–11, Siberian platform: 9, basement metamorphic complexes (AR–PP); 10, cover (undeformed); 11, cover (deformed in the Mesozoic); 12–15, lithospheric plates: 12, with Grenvillian basement; 13, with Late Precambrian basement; 14, with Late Precambrian basement that was subjected to Hercynian tectonic deformations, 15, with Late Precambrian basement that was subjected to Cimmerian tectonic deformations; 16, basalts and bimodal volcanic associations of intraplate type (K1–N); 17, Okhotsk–Chukchi volcanic-plutonic belt (K1–2); 18, Alpha–Mendeleev large igneous province (alkaline basalts, 120–90 Ma); 19, active spreading axis; 20, sutures; 21, thrusts and upthrows; 22, normal faults; 23, detachments; 24, strike-slips; 25, faults with unclear kinematics. from the Late Precambrian to modern times. At the same time the last stages of the evolution of the Arctic in the Mesozoic– Cenozoic are considered in detail in another paper of this issue of the journal (Koulakov et al., 2013). Barents–Kara continental margin The Barents–Kara margin is represented by two plates—the Kara plate or the Kara microcontinent (Vernikovsky et al., 1995) in the east and the Svalbard plate, or Barentsia (Bogatsky et al., 1996) in the west, in which the Franz Josef Land and Spitsbergen archipelagos come above the sea level (ref. Fig. 2). The particularities of the structure of the Barents–Kara continental margins can be characterized by the sizes of the Spitsbergen, Franz Josef Land, Novaya Zemlya, Severnaya Zemlya archipelagos and by comparing them with Northern Taimyr by using drilling data of single wells and geologic-geophysical materials on the offshore areas. Here we will mention only some aspects, which are important for the reconstruction of the tectonic history of the region. According to current investigations the Svalbard plate occupies nearly all the territory of the Barents Sea margin and includes the territories of the Spitsbergen, Franz Josef Land and Novaya Zemlya archipelagos (ref. Fig. 2). The basement of the Svalbard plate is represented by Grenvillian complexes, known on Spitsbergen and Novaya Zemlya (Korago et al., 1992; Korago and Timofeeva, 2005). This leads to the supposition that the formation of the structure of the Svalbard basement took place as a result of collisional events during the amalgamation of Rodinia. Based on paleomagnetic data the Baltica Subcontinent is usually placed in such a way that the Grenvillian Sveconorwegian structures serve as the northern (in modern coordinates) “ending” of the Grenvillian structures of the western margin of Laurentia, while the Meso-Neoproterozoic fold belts of Amazonia are linearly oriented along the Grenvillian margin of Laurentia (Cawood and Pisarevsky, 2006). In this context it is logical to assume that the structures of the Svalbard orogen could occupy the northernmost position relative to Baltica and Laurentia, prolonging the Grenvillian belt and marking the suture between these cratons during the formation of Rodinia. As a result of the collision of the Timan edge of Baltica with the structures of Svalbard the Late Precambrian–Early Paleozoic Timan–Pechora orogen was formed. Its existence is confirmed by a deep cutting out of the Late Precambrian complexes of the basement of the Timan–Pechora plate and by a clearly defined unconformity in the base of the Paleozoic formations of its cover, as well as by the emplacement of I-type (695–515 Ma) and A-type (564–516 Ma) granitoid plutons (Kuznetsov et al., 2005). At the same time geologic and structural data indicate that the collision mode could have been “oblique” (Kuznetsov, 2008). In the far west and southwest, in close proximity to the Caledonian thrust in Western Spitsbergen and Northern Scandinavia, the reworking of the basement was related to the Caledonian motions. Also there are some clues to that the basement of the Franz Josef Land and Spitsbergen region was subjected to tectonic-thermal alteration (metamorphism?) 420 Ma during the main stage of Caledonian metamorphism in Northern Scandinavia (Gramberg, 1988), which could be related to the occurrence of a Devonian orogen in the north of Svalbard plate, probably as a result of collision between Arctida and Euro-America or Arct-Europa with America (Laurentia) (Zonenshain et al., 1990). Within the Kara plate the basement surface is characterized by a complex and rugged geography. The maximum elevations of the most submerged basement zones reach values of 12–14 km (in St. Anna trough, as well as in other basins of the Kara plate), and the minimum ones—1–2 km. Analysis of the geologic structure of the coastal and island framing together with data on potential geophysical fields allows to recognize the structures of the basement of the Severnaya Zemlya and North Taimyr areas to a significant part of the North Kara shelf. As a result this region can be regarded as a single plate mainly with a Precambrian basement. The Precambrian complexes, with which the foundation of the Kara plate is built, are raised above sea level on the Severnaya Zemlya archipelago and in the northern part of Taimyr peninsula (Bogdanov et al., 1998; Kaban’kov et al., 1982; Lorenz et al., 2008; Pogrebitsky, 1971; Proskurnin, 1995; Vernikovsky, 1996). The main elements of the structure of the southern part of the Kara plate are oriented in accordance with the strike of the largest dextral strike-slip zones of its boundary, which indicates a significant role of strike-slip tectonics during the formation of the Taimyr–Severnaya Zemlya orogenic belt. The time of its formation is registered in Late Paleozoic regional metamorphism and granitoid magmatism (306–260 Ma) (Vernikovsky et al., 1995). Here Late Carboniferous syncollisional and Late Permian postcollisional granitoids are distinctly determined. Their composition varies from S-type granites to the intermediate S-I-type and A-type. Petrologic and isotopic-geochemical data of the collisional event are agreeing well with paleomagnetic data (Metelkin et al., 2005) and underlining its kinematic characteristics. During the Late Paleozoic collision of the Kara plate (Kara microcon- 842 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 tinent) and the Siberian craton the Late Neoproterozoic Central Taimyr accretionary belt located between them and containing cratonic terranes, paleoisland arcs and ophiolites fragments was deformed (Khain et al., 1997; Pease et al., 2001; Uflyand et al., 1991; Vernikovsky and Vernikovskaya, 2001; Vernikovsky et al., 1996, 2011). It should be noted that in the structure of geophysical fields (gravitational and magnetic) (Gaina et al., 2010) the Kara plate is noticeably different from the Svalbard plate and adjacent areas of the Siberian craton, therefore it appears to be an independent block with characteristic individual particularities of its inner structure. This must be accounted for when dealing with the issue of relationships and evolution of the Svalbard and Kara plates. In the geography of the Barents–Kara continental margin there are clear deep shut-ins, tectonically corresponding to graben-trenches (or troughs), of which the largest were Franz-Victoria, St. Anna, Voronin (ref. Figs. 2, 3). From the west and north the elements of the platform are cut by flexure/strike-slip belts of continental slopes of the Norwegian–Greenland and Eurasian oceanic basins, respectively. The Precambrian basement blocks of the marginal-continental platform are separated by multiple riftogenic troughs, which had polycyclic developments (Aplonov et al., 1996; Shipilov and Senin, 1988; Shipilov and Vernikovsky, 2010; Verba et al., 2005), the largest among them is the East Barents trough. The East Barents and St. Anna troughs form a combined structure with a triple junction (ref. Fig. 3) and the Voronin trough is probably a more ancient structure. Taking into account the maximum thickness and sedimentation rate, among the riftogenic troughs and basins of the Kara and Svalbard plates one can determine: (1) Late Caledonian–Hercynian (sedimentation maximum in S–D1, unconformity in the base of C2), of which the Voronin trough can be an example; (2) with a maximum in P2–T1 (St. Anna trough and North Barents basin) and (3) Cretaceous (triple junction center in the intersection of St. Anna and East Barents troughs) (Shipilov, 2008; Shipilov and Vernikovsky, 2010). Laptev–Chukchi continental margin The eastern part of the Arctic (ref. Figs. 1, 2, and 4) is represented by the combination of marginal and oceanic structures. In the oceanic part the Eurasian basin with the Gakkel Ridge and the Canada basin are identified, between which the Lomonosov Ridge, the Alpha–Mendeleev Rise are located and they in turn are separated by the Makarov basin. In the continental part, in the framing of the Siberian platform, accretionary-collisional structures are located. They are represented by a fan of ridges—from the Verkhoyansk to Chersky and further to the east with a series of arc-shaped ridges in Koryakiya, Chukotka, and Alaska, where they characterize the folded structures of the Pacific border. The seismic zones (ref. Fig. 4) of the continental part form a fan of structures, widening from the Laptev Sea and the mouth of Lena River towards the Okhotsk seashore and the Kamchatka neck, where the distance across seismogenic structures exceeds 1000 km. This structure is interpreted in a series of papers as a “diffuse” margin of the North American and Eurasian plates (Bogdanov, 1998; Stein and Sella, 2002). However a collage of microplates has long since been identified here, including the Amur, Okhotsk Sea, and Bering Sea (Korago et al., 2010; Zonenshain et al., 1990). On the opposite side of the East Arctic sector, in Alaska and the adjacent part of the Rocky Mountains we also observe a fan-like complex of seismogenic structures. They are connected through the seismogenic structure of the Aleutian island arc and the Chukchi–Koryakian seismic belt (ref. Fig. 4). This seismicity was in a simplified way interpreted as the interaction between the North American and Eurasian plates, which generates the opening of the North Atlantic which continues the Central Arctic through the Gakkel Ridge and the complex interaction between the Siberian and Canada platforms and the Pacific plate, which leads to the formation of the microplates collage. We will consider this interaction with taking into account a new seismic tomography model (Jakovlev et al., 2012) and new data on Cenozoic volcanism in the East Arctic sector. Fig. 4 shows a scheme of current geodynamics of the East Arctic, on which we demonstrate the seismic zones close to those described in (Avetisov, 2009; Poselov et al., 2012; Jakovlev et al., 2012), as well as the South Anyui suture and its continuation in South Chukotka (Miller and Verzhbitsky, 2009; Sokolov et al., 2001, 2009, 2010), the Okhotsk–Chukchi volcanic belt (Late Albian–Campanian (Akinin, 2012)), the Kolyma–Omolon superterrane (microcontinent). The fan of seismogenic faults spreading from the mouth of the Lena River is located between the Verkhoyansk Range and the southwestern margin of the Kolyma–Omolon massif (Imaev et al., 1998). The scheme shows a projection of a cold high-velocity lens in the transitional zone of the upper mantle at depth 640 km (ST2) that was identified on the horizontal seismic tomography section on Fig. 5. This margin is located to the south of the Chukchi prolongation of the South Anyui suture and represents a relict of the South Anyui oceanic plate that subducted in the Early Cretaceous. Fig. 4 also shows the margin of the areas of plume alkaline and moderate alkaline volcanism on Chukotka and Alaska (the Anyui group, Enmelen volcanoes, Devik, Imuruk, St. Michael, Besep, etc. (ref. Fig. 1 in (Dobretsov et al., 2013) of this issue)), close to the supposed margin of the Bering Sea block (Bogdanov, 1998). These areas are also well determined on the horizontal seismic tomography section for depth 220 km (Fig. 5). Thus the Bering Sea block is framed in the south by a slab, subducting to the north in the Alaska island arc zone to a depth of 350–400 km (Fig. 6) (Koulakov et al., 2011; Jakovlev et al., 2012), and in the north—by a cold lens in the intermediate zone of the upper mantle at a depth of 400– 650 km, a relict of the initially south-subducting slab of the Anyui plate (Lobkovsky et al., 2011). On the surface the younger (Late Cretaceous) subduction zone can be manifested in the Chukchi segment of the Okhotsk–Chukchi volcanic zone (ref. Fig. 4). Fig. 3. Tectonic scheme of the Barents–Kara region and adjacent areas, according to (Bogdanov and Khain, 1996, 1998; Shipilov and Vernikovsky, 2010). 1, Precambrian metamorphic complexes of the basement; 2, cover of the Siberian craton: a, undeformed; b, subjected to tectonic deformations in the Mesozoic; 3, lithospheric plates: a, with Grenvillian basement; b, with Late Precambrian basement; c, subjected to Hercynian tectonic deformations; 4, Neoproterozoic Taimyr accretionary belt; 5, Hercynian and Early Cimmerian fold belts and tectonic deformations zones; 6, folded belts of Mesozoides; 7, cover of young plates; 8, troughs with suboceanic type crust; 9, continental Mesozoic rifts; 10, areas with oceanic crust; 11, middle-oceanic rift zone; 12, largest thrusts; 13, largest strike-slips and transform faults; 14, normal faults; 15, undetermined normal faults and strike-slips; 16, edge of the continental slope. V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 843 844 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 Fig. 4. Scheme of modern-day geodynamics and Neogene–Quaternary volcanism of the Northeast of Asia and Alaska (Imaev et al., 1998; Korago et al., 2010) with our additions. 1, active faults, strike-slips, thrusts; 2, margins of modern subduction zones (troughs); 3, spreading zone (Gakkel Ridge); 4, passive faults; 5, Cenozoic depressions; 6, directions and speed (cm/year) of the plates and blocks drift; 7, South Anyui suture; 8, Okhotsk–Chukchi volcanic belt; 9, Omolon superterrane (paleomicrocontinent); 10, projections of the earthquakes centers with more than 7, 6.9–6.0 and less than 6 intensity; 11, manifestations of Neogene–Quaternary volcanism of alkaline and moderate-alkaline composition; 12, rotation poles of plates and blocks (NA, North American plate; BS, Bering Sea plate; OS, Okhotsk Sea plate; BR, Brooks Ridge); 13, isotherms of the heat flow, mW/m2; 14, basalts and bimodal volcanic associations of intraplate type (K1–N); 15, contours of ranges (ST1) of plume Late Cenozoic volcanism of the: A, continental (northeastern) and B, Bering Sea provinces, from (Anikin, 2012), taken from the seismic tomographic horizontal section (220 km), ref. Fig. 5; 16, border of the cold high-velocity lens in the transition zone in the upper mantle at depth 640 km (ST2), taken from the seismic tomographic horizontal section (220 km), ref. Fig. 5. Indeed, the Chukchi and Okhotsk segments demonstrate significant differences in composition and age of igneous rocks (Khanchuk, 2006); however this question must be studied more. The formation of a lens in the C layer approximately 1000 km wide (ref. Fig. 5 and 6) would take at least 30 m.y., if compared to the South Kuril segment of the Kuril arc (Koulakov et al., 2011). The Chukchi–Alaska block has a key significance in the structure of the Eastern Arctic. In a series of publications (Grantz et al., 1998; Khain et al., 2009; Koulakov et al., 2013) it is supposed that the Precambrian structures of the Chukchi– Alaska block, known in the Brooks Ridge and in the East Chukchi Rise, overbuilt the Early Precambrian structures of the Greenland–Ellesmere block and occupied a position close to the northeastern margin of Laurentia. The “tear” of the Chukchi–Alaska tectonic unit from the North American craton took place only in the Jurassic during the opening of the Canada basin (Grantz et al., 1998; Khain et al., 2009). The collision of this subcontinent with the Verkhoyansk–Kolyma margin of Siberia is structurally manifested in the South Anyui zone (ref. Figs. 2, 4), for which suture-identifying Late Jurassic–Early Cretaceous oceanic and island arc associations are typical (Oxman, 2003; Sokolov et al., 2010). The location of this boundary on the shelf is a matter of discussion (Kuzmichev, 2009). Together with (Golonka et al., 2003; Li et al., 2008) we suppose that from the moment of the formation of Rodinia and during the entire Neoproterozoic and Paleozoic the named blocks did not change their position relatively to the North American craton, forming the margin of Laurentia. N.I. Filatova and V.E. Khain believe that a series of geologic facts indicate a possible terrane history for the Chukchi–Alaska unit in the Late Precambrian–Early Paleozoic (Filatova and Khain, 2007; Khain et al., 2009). The most prominent fact is the occurrence of abyssal facies of the Early V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 845 Fig. 5. Anomalies of seismic velocity of P-waves on horizontal sections, obtained as a result of an inversion of actual data for the Arctic region (Jakovlev et al., 2012, with additions). ST1, contours of Late Cenozoic plume volcanism at depth 220 km, whose projections are shown on Fig. 4. ST2, contour of the cold high-velocity lens in the transition zone of the upper mantle at depth 640 km, whose projection is shown on Fig. 4. Paleozoic at the margin of the Greenland–Ellesmere (including Ellesmere Isl. with the Peary ophiolitic allochton (Klemperer et al., 2002)) block, as well as the widespread manifestation of the structural unconformity surface, as well as deformations, metamorphism, and granitoid magmatism, due to the Elles- mere orogenesis. In a published model (Lawver et al., 2011) it is supposed that before the Devonian the Chukchi–Alaska block formed the northeastern (modern coordinates) framing of the Siberian continent and the Ellesmere orogenesis reflects its collision with Laurentia. The rifting that followed it led to 846 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 Fig. 6. Vertical sections of the model of seismic anomalies of P-waves velocity along three vertical sections, whose locations are shown on Fig. 5. The main geographic elements are indicated above the traverses. CA, Chukchi anomaly, whose origin is discussed in the text. the formation of the Angayucham oceanic basin (South Anyui ocean) and by the end of the Devonian—in the Carboniferous Siberia was separated from the Greenland–Alaska–Chukchi margin of Laurentia by an already wide space (Lawver et al., 2011). The New Siberian block is another key structure of the Arctic (ref. Fig. 2). It is included in the Russian Arctic shelf and, according to many researchers, is a continental terrane with a Precambrian basement and a Paleozoic, mostly carbonaceous cover (Drachev et al., 1998; Kos’ko, 1977; Natal’in et al., 1999). However, many questions concerning its structure and margins are under intense discussion. The traditional views regard this tectonic unit that includes the territory of the New Siberian Islands and the surrounding Laptev Sea shelf (ref. Fig. 2) in the structure of the New Siberian–Chukchi–Brooks fold and thrust system (Filatova and Khain, 2007). Consequently in nearly all reconstructions it is included in the Chukchi–Alaska terrane. However the position of the western margin of this terrane, where the New Siberian block is located is still discussed (Drachev, 2011; Kuzmichev, 2009). Among other things it is supposed that this all-important boundary could divide the New Siberian block in two by passing between Kotelny and Faddey islands or between them and New Siberia Island, or between the Anzhu and De Long Islands. The latter is explained by the existence of anomalies of the gravitational and magnetic fields (Gaina et al., 2010, 2011), as well as by weak seismicity (Poselov et al., 2012), which allows the supposition of a riftogenic structure (Drachev et al., 2010). However, as we show next, the first ever paleomagnetic data for the New Siberian islands allows us to say that the rocks of the Anzhu and De Long archipelagos rocks formed within a unified New Siberian terrane at least from the Early Ordovician, that is to say on the same basement (Vernikovsky et al., 2013). In this case the New Siberian block becomes comparable in size to the Kara block and by analogy with the latter can be regarded as the New Siberian plate or the New Siberian microcontinent. The riftogenic structure assumed above that supposedly divides the New Siberian as V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 such and the De Long Islands can be very young, and its formation has not yet led to the breakup of the united block and the displacement of its parts. The possibility of the appurtenance of the New Siberian block to the marginal structures of Siberia or the Kara block is discussed (Kuzmichev and Pease, 2007). The Paleozoic part of the section, building the New Siberian Islands, is described as a typical shelf of a passive continental margin. The most complete section is known on Kotelny Island, where it has mainly a carbonaceous composition. More distal facies with the predominance of turbidites is typical for the Lower Paleozoic complex on Bennett Island (Vernikovsky et al., 2013). These sections have a similarity with the deposits composing the series of carbonate blocks of the Omulevkatype along the Polousny–Kolyma suture that form the Kolyma structural loop (Oxman, 2003). New biostratigraphic data on the Ordovician–Silurian indirectly confirm the relative nearness of the paleobasin and the Siberian margin (Vernikovsky et al., 2013). Geologic and geophysical data used in geodynamic reconstructions The data available in the 60–80s of the last century on the existence of Precambrian metamorphic and igneous complexes amongst the main structures of the Arctic framing the ocean allowed many authors to assume the existence of an ancient continent between Laurentia, Siberia and Baltica that was variously called the Hyperborean platform, Barentsia, Arctida or the Arctic continent (Khain, 1979; Shatsky, 1963–1965; Zonenshain and Natapov, 1987; etc.). This ancient continent, which is now more and more often called Arctida thanks to L.P. Zonenshain and L.M. Natapov, was broken up as a result of rifting and its various continental blocks either were overlain with continental margin sediments or were included in fold belts on the periphery of the ocean (Fig. 7). In the classic representation Arctida consisted of several blocks of sialic crust, whose relicts are now located in the Arctic sector: the Kara block, the New Siberian block (New Siberian Islands and adjacent shelves), the North Alaska block (Brooks Ridge, Seward Peninsula), and the Chukchi block, as well as small fragments of the Inuit fold belt in the north of Greenland (Peary Land, the northern part of Ellesmere and Axel Heiberg islands) and the block of the submerged Lomonosov Ridge (Zonenshain and Natapov, 1987). These authors did not include the Barents–Spitsbergen block into Arctida, although they considered the Timan belt as a suture marking the collision of the lesser Barentsia continent with Eastern Europe (Baltica) in the Late Precambrian. Later a number of researchers developing these ideas included Barentsia in the structure of Arctida (Arctic continent) in their reconstructions, noting like the authors mentioned above, the Late Precambrian (Vernikovsky, 1996) or Vendian–Cambrian age of its collision with Baltica (Borisova et al., 2001; Kuznetsov, 2008). At the same time T.P. Borisova et al. named the newly constructed continent “Arct-Europe”, 847 which included Arctida and Baltica, and which later combined with the North American continent—Laurentia with the formation of a Caledonian fold belt and a new continent— Arct-Laurussia or Euro-America. In the opinion of Zonenshain and co-authors the collision of Eastern Europe with North America took place before the Devonian, and the collision of Euro-America and Arctida—in the Devonian (Zonenshain and Natapov, 1987; Zonenshain et al., 1990). By the Late Carboniferous–Early Permian Euro-America including Arctida approached Siberia, which led to the closure of the Ural paleoocean (Dobretsov, 2003; Zonenshain et al., 1990), the formation of the Kara (Taimyr–Severnaya Zemlya) orogenic belt (Vernikovsky, 1996) and the South Anyui oceanic bay (Zonenshain et al., 1990). The evolution of the continental blocks of the Arctic was considered by many foreign authors. Among them in the 80s of the last century based on the analysis of seismic data some suppositions were made on the continental nature of the rises of Lomonosov and Mendeleev (Churkin and Trexler, 1981; Forsyth and Mair, 1984; Jackson and Johnson, 1984; etc.), which today find more and more confirmations (Alvey et al., 2008; Grantz et al., 2001; Langinen et al., 2009). According to materials of complex geologic and geophysical investigations conducted in recent years on Lomonosov Ridge and in the zone of its junction with the Laptev–Chukchi continental margin, a distinct genetic link between it and the structures of the shelf regions has been determined (Lebedeva-Ivanova, 2006; Poselov et al., 2012; Rekant and Gusev, 2012). It has been shown that the tectonic structure of the ridge cannot be considered separately from adjacent continental structural ensembles. The ridge is an ancient continental crust block submerged to bathial depths that evidently is a fragment of the corresponding masses and formed during the formation of the current structure of the Eurasian basin. A reliable substantiation for the relative configuration of the blocks composing Arctida in space and time could be done with paleomagnetic data. Unfortunately, a severe lack of quality paleomagnetic data for the Late Precambrian and Paleozoic on the Arctic territory does not allow us to compose a “mature” palinspastic basis for paleotectonic analysis (Vernikovsky et al., 2010). The International paleomagnetic database (IAGA GPMDB) has no more than 30 determinations, mainly for the Late Paleozoic (younger than the Devonian)–Early Mesozoic for the territory of Barentsia and the Greenland–Ellesmere region. For the territory of Chukotka and Northern Alaska—the largest fragment of the classic Arctida—no paleomagnetic determinations exist. Reliable paleomagnetic data exist for the Kara block. They include three paleomagnetic poles for 500, 450 and 420 Ma that allowed justifying the apparent polar wander path (APWP) for this plate (Metelkin et al., 2005). The character of the apparent wander and the latitudes are similar to those of the Siberian poles (Cocks and Torsvik, 2007) and the APWP of Baltica (Torsvik and Cocks, 2005), but it deviates significantly to the east. The latter is interpreted as the validation of the tectonic unity of the Baltica and Kara blocks in the structure of the hypothetical Arct-Europe (Gee et al., 2006; Kuznetsov, 2008), Fig. 7. The main geologic structures of the Arctic (a) and a reconstruction for the Early Jurassic, showing the ancient arctic masses, assembled in the Arctida continent, attached to Laurasia (b) (Zonenshain and Natapov, 1987). 1, oceanic basins deeper that 2000 m; 2, isobaths for 2000 and 3000 m; 3, active spreading center (a, definite, b, diffusive or indefinite); 4, shields; 5, platform; 6, orogenic belts; 7, ancient masses, remains of the Arctida continent; 8, Mesozoic and Cenozoic sedimentary basins; 9, folding fronts; 10, dead spreading axis; 11, continental contours; 12, blocks contours; 13, the Canada basin shelf contour; 14, areas of blocks overlapping in the reconstruction. 848 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 although in fact it means only that the relative position of the continental masses in the Early Paleozoic was similar to their current spatial configuration. A detailed consideration reveals that the angular space between the poles of the Baltica and Kara blocks for the Cambrian–Ordovician boundary is 10º– 40°, and for the Silurian it is 20º–30°, and only the Late Ordovician poles are not statistically different. Data synthesis and analysis of the reconstructed kinematics of the Kara plate, Siberia and Baltica lead to the conclusion that the Kara continental mass had a terrane history in the Paleozoic (Metelkin et al., 2005, 2012). From the Ordovician to the Late Silurian the terrane experienced a drift from 40° S to 10° N with a speed of approximately 5 cm/year and a counter clockwise rotation of 1°/m.y. A similar drift, however with a faster plate rotation is reconstructed for Baltica (Torsvik and Cocks, 2005). The main difference in the kinematics of the Siberian plate is clockwise rotation (Cocks and Torsvik, 2007). The oppositely directed rotation of the blocks should have established the formation of transforms between them and aided the strike-slip motion of the Kara plate from Baltica (or Laurentia) towards Siberia. It is probable that the relicts of these transforms serve as controlling structures in the formation of the St. Anna trough and North Siberian step (Fig. 2). Thus, based on the listed geologic and geophysical data we suppose that in the structure of Arctida (during the formation of Rodinia) the Kara block was located between the Greenland–Ellesmere block as a continuation of its structures and Svalbard. Its Paleozoic history corresponds to a terrane stage, and therefore consisted of “tearing” from the Canada margin of Laurentia and drifting towards the Taimyr margin of Siberia. Moreover, during this drift, large transforms should have played a determining role, including those functioning between the Kara microcontinent and Svalbard. Our first investigations of the Early Paleozoic of the New Siberian Islands let us determine the coordinates of paleomagnetic poles for the Early, Middle Ordovician and the Late Ordovician–Early Silurian and establish the following patterns (Vernikovsky et al., 2013). First, the coincidence of paleomagnetic directions determined in sedimentary rocks of Kotelny Isl. and Bennett Isl. tell us that the rocks of the Anzhu and De Long archipelagos formed within one single New Siberian terrane (microcontinent) at least since the Early Ordovician, which means on the same basement. The South Anyui suture we discussed earlier could not cross it even during the opening of the Amerasian basin in the Early Cretaceous. Secondly, the coordinates of the paleomagnetic poles we obtained differ significantly from the corresponding interval of the apparent polar wander paths for Siberia, Laurentia and the Kara microcontinent. The most favourable interpretation of the paleomagnetic data is the version in which the New Siberian block was an independent terrane in the Early Paleozoic. Its paleogeographic position at the Ordovician–Silurian boundary was 30°–40° of supposedly northern latitudes. Considering the existence of mafic subvolcanic intrusions on Bel’kovsky Isl., which can be compared to the episode of trap magmatism in 849 Siberia (Kuzmichev and Goldyrev, 2007; Kuzmichev and Pease, 2007), we should consider the possibility of a preMesozoic collision of the New Siberian block with the Siberian margin. In this case the territory of the New Siberian archipelago could have found itself in the zone of influence of the Siberian plume when supposedly occupying a marginal position in the structure of the Siberian trap province (Kusmichev and Goldyrev, 2007). These paleomagnetic data for the territory of the Kara and New Siberian microplates, together with the extensive paleomagnetic database for the Laurentia, Baltica, Siberia and Gondwana cratons (Li et al., 2008; Metelkin et al., 2010, 2012; McElhinny and MacFadden, 2000; Pechersky and Didenko, 1995; Pisarevsky et al., 2008; Smethurst et al., 1998; Torsvik and Van der Voo, 2002; Torsvik et al., 1996; Wingate and Giddings, 2000) became the basis for the paleotectonic reconstructions we present here. The paleogeographic position of the cratons is corrected (within the margins of error of paleomagnetic poles) in accordance with the general model and available global reconstructions that include the structures of the Arctic sector (Cocks and Torsvik, 2002, 2007; Golonka et al., 2003; Lawver et al., 2011; Scotese, 1997). The position of the Arctida blocks for time intervals that lack paleomagnetic data is reconstructed based on geologic considerations. Paleotectonic reconstructions 750 Ma. This time is associated with the breakup of Rodinia—the Grenvillian supercontinent that formed ~1 Ga. We assume (Li et al., 2008) that the Arctida structures within Rodinia, including Svalbard, the Kara block, the Greenland– Ellesmere, Alaska–Chukchi and New Siberian blocks occupied a band between the Canadian margin of Laurentia, the southwestern margin of Siberia and the northeastern margin of Baltica. According to current views the breakup of Rodinia began as soon as ~950 Ma and went on for a very long time, up to the Ediacaran. Strike-slips had an important role in this process, by actually determining the “tectonic demolition” of the supercontinent (Metelkin et al., 2012). By 750 Ma the Siberian craton had already detached and strike-slip systems dominated along the Grenvillian orogenic belt. The Paleogeographic position of the Arctic subcontinent was in subequatorial latitudes (Fig. 8). The most ancient ophiolites that mark the paleooceanic margins at 1000–900 Ma were identified at the Taimyr (Vernikovsky et al., 2011). 650 Ma. There are many examples showing that the breakup of the supercontinent was accompanied by the destruction of the margins of plates into independent terranes, microcontinents, small and average plates. By the end of the Cryogenian, during the intense formation of oceanic crust of the Paleo-Asian Ocean that divided Siberia and Laurentia, the destruction of the Laurentian margin involved most of the blocks of ancient Arctida (ref. Fig. 8). The New Siberian block located in the northern periphery, was one of the first to detach. In the context of the presented kinematic setting the block’s furthermost northern position predetermined its indi- 850 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 Fig. 8. Plate tectonic reconstructions showing the position of the continents and blocks of Arctida in the Neoproterozoic–Early Paleozoic. 1, continental masses; 2, continental blocks of Arctida; 3, oceanic basins; 4, inferred position of spreading zones; 5, active continental margins; 6, general strike of the transform/strike-slip zones with indicated strike-slip kinematics. vidual tectonic history in the Northern Hemisphere. The Kara and Svalbard plates, which occupied a southern position in the structure of ancient Arctida, were detached somewhat later as a result of rifting that spread southward and in the end conditioned the isolation of Baltica and its sharp clockwise rotation. Such a rotation was supported by the evolution of the active continental margin located close to the Timan–Ural margin of Baltica. Oblique subduction on one hand and extension on the other caused the transform character of its drift and interaction with the Kara microplate. In the Late Neoproterozoic these microplates together with their large neighbours were moved southward and occupied the subtropical latitudes of the Southern Hemisphere. 540 Ma. In the evolution of the Svalbard plate the Precambrian–Cambrian boundary was marked by a collisional event that resulted in the formation of the Timan–Pechora V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 orogen, which sutured the plate with the timanian margin of Baltica (Kuznetsov, 2008; Kuznetsov et al., 2005). From this moment this territory of Barentsia was a part of the East-European paleocontinent (Nikishin et al., 1996). The Kara block continued to experience a mostly transform drift relatively to Barentsia. The strike-slip mode characterized the entire northeastern (in modern coordinates) margin of the Siberian plate and its interactions with the Laurentia and Baltica plates (Fig. 8). The southwestern margin of Siberia of this time was in a setting of active continental margin of pacific type experiencing oblique subduction, which contributed to the clockwise rotation typical for Siberia starting from the Cambrian (Metelkin, 2013; Metelkin et al., 2012). It is probable that from this time the New Siberian block started its approach from the plates of the Paleo-Asian Ocean towards the Siberian continental margin. The motions had a transform kinematic. The orientation of the transforms that controlled the drift of the New Siberian block was practically parallel to the sublatitudinal strike of the subduction system in the south of Siberia. This not only led to the mostly strike-slip motion of the New Siberian plate along the Siberian margin, but also caused this block to remain in relatively high northern latitudes. Another important event on the Precambrian–Cambrian boundary was the birth of the Iapetus Ocean on the margins of Laurentia and Baltica, which determined the subsequent drift of Laurentia (Cocks and Torsvik, 2002). 500 Ma. By the Cambrian–Ordovician boundary the Iapetus oceanic space was characterized by an active spreading regime between Laurentia and Baltica (Cocks and Torsvik, 2002). This time was marked by processes of continental crust breakup along the eastern (modern coordinates) margin of Baltica with the formation of the oceanic floor of the Ural paleoocean (Dobretsov, 2011; Puchkov, 2003). Thus the East-European continent was nearly on the entirety of its periphery (except the north) surrounded by young oceanic basins, whose growth dynamic determined the active counter clockwise rotation of the continental plate. The northern margin of Baltica, including the margin of Barentsia, had a transform development mode. Large scale strike-slips connected the northern margins of Baltica and Siberia, providing a gradual drift for the Kara block towards Siberia (Metelkin et al., 2000, 2005). The latter after an intense accretionary event in the southwest from the side of the Paleo-Asian Ocean continued to experience clockwise rotation, which led to lamination of the newly formed continental crust and intense strike-slip deformations (Metelkin, 2013; Metelkin et al., 2012). The ongoing development of this strike-slips system in the southeastern margin of Siberia (in modern coordinates) connected and controlled the on-coming drift of the New Siberian block, which now found itself in the influence zone of the plates of the Paleo-Pacific. 450 Ma. The end of the Ordovician was marked by the beginning of the closure of the Iapetus oceanic space (Fig. 9). Active subduction processes manifested everywhere on its continental margins (Cocks and Torsvik, 2005). The Barentsia margin of Baltica and the Kara terrane on its periphery 851 experienced a significant rapprochement with the Kara margin of Siberia mainly because of their rotation in opposite directions. The whole system continued its general northward drift to the equator. The position of the New Siberian block on this reconstruction close to 30° N corresponds to paleomagnetic data (Vernikovsky et al., 2013). The New Siberian terrane also experienced a drift conformal to that of Siberia, which was controlled by sinistral strike-slips at the craton’s periphery, according to models already published (Metelkin et al., 2012). 420 Ma. The Silurian–Devonian boundary was marked by the closure of the Iapetus Ocean and the collisional event between Laurentia and Baltica and their unification into Laurussia (Cocks and Torsvik, 2002). At the same time as the formation of the Scandinavian orogen, the Caledonian orogeny manifested itself in the northwestern part of Spitsbergen and the northeastern margin of Greenland, continuing to spread along the Greenland–Ellesmere area of Laurentia and reaching Alaska in the Late Devonian–Early Carboniferous (Filatova and Khain, 2007; Khain et al., 2009). By the end of the Silurian the Ellesmere–Alaska margin of Laurentia was an active margin, where relicts of the Iapetus oceanic crust were subducted. The Kara microcontinent already was located directly near the Taimyr margin of Siberia (ref. Fig. 9). The early stages of its collision consisted in sliding along a transform, which does not exclude the existence of oceanic crust fragments between Siberia and the Kara microplate (Metelkin et al., 2005). Apparently a thin “gap” of oceanic crust also existed between the Svalbard plate and the Kara microcontinent. The Ural margin of Baltica and the southwestern margin of Siberia were characterized by intense subduction magmatism, which indicates the closure mode of the Ural and Paleo-Asian oceanic basins (Dobretsov, 2011). The active rapprochement of the Siberian and East-European masses was due to the domination of subduction and strike-slip modes within their current arctic margins (Metelkin et al., 2012). As a result, by the end of the Devonian, most of the arctic blocks except the New Siberian terrane found themselves near each other again in a subequatorial position (ref. Fig. 9). 380 Ma. According to modern views (Golonka et al., 2003) when the Devonian began the blocks of Arctida composed a continental bridge between Siberia and Laurussia, joining the structures of the supercontinent. In the Middle Devonian a spreading zone and a narrow oceanic basin are assumed to have formed in this region separating the Chukchi–Alaska margin of Laurentia and the Lena–Anabar margin of Siberia (Golonka et al., 2003). According to our reconstructions and the interpolation of paleomagnetic data for the Early Paleozoic of the Kara terrane (Metelkin et al., 2005) we assume that the Siberian margin in the Silurian–Devonian did not have any common boundaries with Laurussia. This peculiar bay of the Paleo-Pacific separated these continental blocks during the entire Late Paleozoic. They came closest to each other in the end of the Silurian when an active continental margin could have been evolving at the Chukchi–Alaska periphery. In the Devonian this margin was turned into a transform (ref. Fig. 9). The transform mode was dominant along all the continental 852 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 Fig. 9. Plate tectonic reconstructions showing the position of the continents and blocks of Arctida in the Middle Paleozoic. See legend keys on Fig. 8. margins of Arctida in the Middle Paleozoic. Strike-slips provided the sliding of the Siberian and Kara continental plates systems to the right along the northwestern margin of Laurussia, which led to the further transformation of the bay mentioned above into a wide, marginal sea basin. This basin opened towards the Paleo-Pacific and united the Chukchi– Alaska, Svalbard, Kara, and Priverkhoyan shelves. We assume that a sinistral strike-slip system existed along the latter, causing the drift of the New Siberian block to its current position. This kinematic agrees well with the predominant tectonic processes in the other oceans and their margins. Among these the Devonian interval is associated with a subduction setting on the Siberian margin of the Paleo-Asian ocean (Saraev et al., 2012; Wilhem et al., 2012) and the Baltica margin of the Ural paleoocean (Puchkov, 2000). The dominating subduction contributed to the withdrawal of the Siberian paleocontinent and the Arctic blocks of its margin from the Chukchi–Alaska margin of Laurentia. Available paleomagnetic data for 380 Ma lead us to assume that the narrow area of the southeastern Laurussia margin was in contact with the Amazonian margin of Gondwana (Torsvik and Van der Voo, 2002). The oceanic space between Laurentia and the African margin of Gondwana, known as the Rheic Ocean (Linnemann et al., 2008; Murphy et al., 2006) was in active closure, whereas at this time the Paleo-Tethys could V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 853 Fig. 10. Plate tectonic reconstructions showing the position of the continents and blocks of Arctida in the Late Paleozoic. See legend keys on Fig. 8. have been growing. Thus the presented kinematic assumes a strike-slip development mode for the margin of Laurussia and Gondwana (Fig. 9). 355 Ma. The global tectonic regime did not undergo any significant alterations in the Early Carboniferous. The reconstructed arctic blocks and the related continents moved a little to the north. The New Siberian terrane drew significantly closer to the main group of Arctida landmasses. A relatively calm tectonic regime characterized this entire shelf of the Paleo-Pacific, which was opening due to the withdrawal of Siberia. It is probable that the main cause for this strike-slip was spreading inside the Paleo-Pacific, causing the corre- sponding direction of movement of the oceanic plates. The closure of the Paleo-Asian and Ural oceans system, which were located on the opposite side of the Siberian paleocontinent, aided the transform development regime for this paleoshelf. Active subduction processes manifested also in the other paleooceans that divided the blocks of the Gondwanian and Laurentian–Siberian continental groups. From this time a tendency to amalgamation of continental masses into a single continent is clearly seen (Fig. 9). 330 Ma. During the Carboniferous all continents continued to drift northwards, getting nearer to each other (Fig. 10). The Rheic Ocean was almost closed even at the beginning of this 854 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 period (Linnemann et al., 2008; Murphy et al., 2006). Active subduction processes continued on the Ural margin of Baltica (Filippova et al., 2001; Puchkov, 2000; Windley et al., 2007). A large subduction zone appeared on the other margin of the Ural Ocean dipping under Kazakhstan and marked by the Valerianov volcanic belt (Filippova et al., 2001; Wilhem et al., 2012). As a result of two-sided subduction the space of the Ural Ocean decreased rapidly and we suppose that its width was less than 500 km. The last basins of the Paleo-Asian Ocean closed in a setting of oblique subduction (the Ob’– Zaisan Ocean) (Korobkin and Buslov, 2011; Windley et al., 2007). Thus active processes associated with the closure of paleooceans captured the entire southeastern (in ancient coordinates) margin of the continental masses of Laurentia, Baltica, and Siberia. At the same time the opposite northwestern shelf kept a relatively calm tectonic mode. The arctic blocks were located in a chain one after another along ~30° N from west to east: Chukchi–Alaska, Svalbard, Kara, New Siberian, and probably experienced insignificant strike-slip motions relative to each other (Fig. 10). 305 Ma. The Carboniferous–Permian time of the Earth’s history is characterized by the age of the main continental collisions during the formation of Pangea (Dobretsov, 2003; Golonka and Ford, 2000; Zonenshain et al., 1990). The collision is noted on the Ural, where also a large scale strike-slip system is clearly manifested (Puchkov, 2000). We suppose that the strike-slips deformed in the strongest way the fold and thrust structure of the Ural orogen in the Late Permian–Triassic, however their emplacement was logically linked to the pre-Late Paleozoic kinematic of the interacting continental masses of Laurasia that we described earlier. The start of the collisional stage is marked between Siberia and Kazakhstan (Wilhem et al., 2012); however the reconstruction shows a small space between these continents with an active subduction zone (Fig. 10). A specific collision setting characterized the Taimyr margin of Siberia (Metelkin et al., 2005; Vernikovsky, 1996). Here the “continent–microcontinent” collision took place as a soft interaction of sialic masses in conditions of oblique encounter and their rotation relative to each other. The early stages of this collision were accompanied by the sliding of sialic masses along a transform, which does not exclude the existence of oceanic crust fragments between Siberia and the Kara microplate. Geologic data indicate that the conclusion of the collisional processes took place in the Late Carboniferous–Permian with the formation of the Taimyr–Severnaya Zemlya fold belt (Pogrebitsky, 1971; Vernikovsky, 1996). This is confirmed by isotopic dates of three generations of granitoids—Late Carboniferous, Early- and Late Permian, among which the last is considered as postcollisional (Vernikovsky et al., 1995) and by paleomagnetic data (Metelkin et al., 2005). The lithosphere, well heated by collisional processes contributed on the Taimyr to the formation of granitoids and syenites even in the Early Triassic, which are linked to the manifestations of the Siberian superplume (Dobretsov and Vernikovsky, 2001; Vernikovsky et al., 2001, 2003). 280 Ma. In the Early Permian the blocks of Laurasia and Gondwana were already united into the Pangea supercontinent (Fig. 10). None the less the deformations caused by the orogenic events within the Laurasian part and now related mostly to strike-slips went on. In accordance with paleomagnetic data the intraplate strike-slip displacements of large and rigid tectonic units of the Eurasian continent (Siberian and East European cratons) went on until the Late Mesozoic (Metelkin et al., 2010, 2012). 255 Ma. By the end of the Permian as a result of a mainly transform rapprochement of the Kara–New Siberian and Chukchi–Svalbard continental margins the unification of the arctic masses in the structure of a single shelf was over. Thus the Permian–Triassic boundary can be called the time of the second formation of Arctida, this time within Pangea. The arctic continental masses were located in the northern margin of Pangaea in the region of the 60th latitude, occupying moderate and subpolar areas of the Northern Hemisphere (ref. Fig. 10). Conclusions The analysis of the particularities of the tectonic structure of key units of the Russian part of the Arctic region and our new geologic-geophysical data presented in this paper allow the possibility of building geodynamic reconstructions for individual continental blocks of the Arctic region, as well as for their ensembles in the form of paleocontinents or subcontinents. No doubt, some of our conclusions need to be specified or verified by additional investigations. Unfortunately there are still many white spots in the field of tectonic structure of the Arctic, and all the more so, in the issues of the evolution of the units of the Arctic region. However, the obtaining of new geologic-geophysical data, including paleomagnetic, for each Arctic structure lets us to better understand its formation history, as well as the evolution of the Arctic region as a whole. This paper develops the ideas of L.P. Zonenshain and L.M. Natapov on the Precambrian Arctida paleocontinent. This Precambrian paleocontinent was in the structure of Rodinia and located between Laurentia, Siberia and Baltica approximately one billion years ago. The processes of Rodinia’s breakup led to the breakup of the Arctic paleocontinent into independent microcontinents and terranes, among which the Kara, Svalbard, New Siberian blocks must be included among others. After considering the evolution of these blocks during the Late Precambrian and the entire Paleozoic we conclude that the units separated in the Late Precambrian formed a Late Paleozoic subcontinent—Arctida-II, which again “sutured” the continental masses of Laurentia, Siberia and Baltica, this time within Pangea. We demonstrate the further Meso-Cenozoic tectonic history of the structures of the Arctic sector in (Koulakov et al., 2013; Laverov et al., 2013; Lobkovsky et al., 2011). It is related to the detachment of the Chukchi–Alaska fragment and Laurentia as a whole, accretionary-collisional events on the Verkhoyansk V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 margin with the formation of the Verkhoyansk–Chukchi fold-and-thrust region, rifting that led to the formation of the Canada, Eurasian and other arctic basins, which finally led to the emplacement of the current structure of the Arctic. This work was prepared within the framework of the project on the State contract of Rosnedra—RAS “Plotting of plate tectonic reconstructions and stress conditions models of the lithosphere of the Arctic region in relation to the problem of widening the outer margin of the continental shelf of the Russian Federation”, with support from the ONZ-1 program of the Earth sciences division of the RAS and the RFBR grant No. 10-0500128. References Akinin, V.V., 2012. Late Mesozoic and Cenozoic Magmatism and Alteration of the Lower Crust in the Northern Framing of the Pacific. Doctorate Dissertation Thesis. IGEM RAS, Moscow. Alvey, A., Gaina, C., Kusznir, N.J., Torsvik, T.H., 2008. Integrated crustal thickness mapping and plate reconstructions for the high Arctic. Earth Planet. Sci. Lett. 274, 310–321. Aplonov, S.V., Shmelev, G.B., Krasnov, D.K., 1996. Geodynamics of the Barents-Kara shelf: geophysical evidence. Geotectonics (Geotektonika) 30 (4), 309–326 (58–76). Avetisov, G.P., 2009. Seismological investigations of NIIGA-VNIIOkeangeologiya in the Arctic (history, accomplishments, prospects). Problemy Arktiki i Antarktiki 82 (2), 27–41. Bogatsky, V.I., Bogdanov, N.A., Kostuchenko, S.L., Senin, B.V., Sobolev, S.F., Shipilov, E.V., Khain, V.E., 1996. Explanatory note to the Tectonic map of the Barents Sea and the Northern part of European Russia. Scale 1:2,500,000 [in Russian]. Inst. Lithosphere RAS, Moscow. Bogdanov, N.A., 1998. Boundary between the Eurasian and North American Plates in the eastern Arctic regions. Geotectonics (Geotektonika) 32 (2), 70–80 (4–16). Bogdanov, N.A., Khain, V.E. (Eds.), 1996. Tectonic Map of the Barents Sea and the Northern Part of European Russia. Scale 1:2,500,000 [in Russian]. ISLAN, PKO “Kartografiya”, Moscow. Bogdanov, N.A., Khain, V.E., Rosen, O.M., Shipilov, E.V., Vernikovsky, V.A., Drachev, S.S., Kostyuchenko, S.H., 1998. Explanatory note to Tectonic Map of the Kara and Laptev Seas and North Siberia (scale 1:2,500,000) [in Russian]. Inst. Lithosphere of Marginal and Inner Seas RAS, Moscow. Borisova, T.P., Gertseva, M.V., Yegorov, A.Yu., Kononov, M.V., Kuznetsov, N.B., Shipunov, S.V., Zykin, V.S., 2001. The Arct-Europe supercontinent and its meaning for global plate tectonic reconstructions, in: Paleomagnetism and Magnetism of Rocks: Theory, Practice, Experiment [in Russian]. Geos, Moscow, pp. 93–96. Cawood, P.A., Pisarevsky, S.A., 2006. Was Baltica right-way-up or upsidedown in the Neoproterozoic? J. Geol. Soc. London 163, 753–759. Cocks, L.R.M., Torsvik, T.H., 2002. Earth geography from 500 to 400 million years ago: a faunal and paleomagnetic review. J. Geol. Soc. London 159, 631–644. Cocks, L.R.M., Torsvik T.H., 2007. Siberia, the wandering northern terrane, and its changing geography through the Paleozoic. Earth Sci. Rev. 82, 29–74. Churkin, M., Trexler, J.H., 1981. Continental plates and accreted oceanic terranes in the Arctic, in: The Ocean Basins and Margins, Vol. 5: The Arctic Ocean. Plenum Press, New York, pp. 1–20. Dobretsov, N.L., 2003. Evolution of structures of the Urals, Kazakhstan, Tien Shan, and the Altai–Sayan region within the Ural-Mongolian fold belt (Paleoasian Ocean). Geologiya i Geofizika (Russian Geology and Geophysics) 44 (1–2), 5–27 (3–26). 855 Dobretsov, N.L., 2011. Early Paleozoic tectonics and geodynamics of Central Asia: role of mantle plumes. Russian Geology and Geophysics (Geologiya i Geofizika) 52 (12), 1539–1552 (1957–1973). Dobretsov, N.L., Vernikovsky, V.A., 2001. Mantle plumes and their geological manifestations. Int. Geol. Rev. 43, 771–787. Dobretsov, N.L., Vernikovsky, V.A., Karyakin, Yu.V., Korago, E.A., Simonov, V.A., 2013. Mesozoic–Cenozoic volcanism and geodynamic events in the Central and Eastern Arctic. Russian Geology and Geophysics (Geologiya i Geofizika) 54 (8), 874–887 (1126–1144). Drachev, S.S., 2011. Tectonic setting, structure and petroleum geology of the Siberian Arctic offshore sedimentary basins, in: Spencer, A.M., Embry, A.F., Gautier, D.L., Stoupakova, A.V., Sørensen, K. (Eds.), Arctic Petroleum Geology. Geol. Soc. London, Memoirs 35, pp. 369–394. Drachev, S.S., Savostin, L.A., Groshev, V.G., Bruni, I.E., 1998. Structure and geology of the continental shelf of the Laptev Sea, Eastern Russian Arctic. Tectonophysics 298, 357–393. Drachev, S.S., Malyshev, N.A., Nikishin, A.M., 2010. Tectonic history and petroleum geology of the Russian Arctic Shelves: an overview. Petroleum Geology Conference Series, Geological Society, London, Vol. 7, pp. 591– 619. Filatova, N.I., Khain, V.E., 2007. Tectonics of the Eastern Arctic Region. Geotectonics (Geotektonika) 41 (3), 171–194 (3–29), doi: 10.1134/ S0016852107030016. Filippova, I.B., Bush, V.A., Didenko, A.N., 2001. Middle Paleozoic subduction belts: The leading factor in the formation of the Central Asian fold-and-thrust belt. Russ. J. Earth Sci. 3 (6), 405–426. Forsyth, D.A., Mair, J.A., 1984. Crustal structure of the Lomonosov Ridge and the Fram and Makarov basins near the North Pole. J. Geophys. Res. 89, 473–481. Gaina, C., Saltus, R., Aaro, S., Damaske, D., Ebbing, J., Forsberg, R., Glebovsky, V., Johnson, K., Jonberger, J., Koren, T., Korhonen, J., Litvinova, T., Oakey, G., Olesen, O., Pilkington, M., Rasmussen, T., Saltus, R., Schreckenberger, B., Smelror, M., Harrison, C., St-Onge, M., Tella, S., Paul, D., Lynds, T., Petrov, O., Strelnikov, S., Shokalsky, S., Lopatin, B., Wilson, F., Hults, C., Bergman, S., Solli, A., Jepsen, H.F., 2010. Circum-Arctic Mapping Project: New Magnetic Anomaly Map Linked to the Geology of the Arctic. Scale 1:5,000,000. Stereographic North Pole Projection. Standard Parallel 70° N Coordinate System WGS 1984 [in Russian]. Gaina, C., Werner, S.C., Saltus, R., Maus, S., 2011. Circum-Arctic mapping project: new magnetic and gravity anomaly maps of the Arctic, in: Spencer, A.M., Embry, A.F., Gautier, D.L., Stoupakova, A.V., Sørensen, K. (Eds.), Arctic Petroleum Geology Book Series. Geol. Soc. Memoirs 35, pp. 39–48, doi: 10.1144/M35.3. Gee, D.G., Bogolepova, O.K., Lorenz, H., 2006. The Timanide, Caledonide and Uralide orogens in the Eurasian high Arctic, and relationships to the paleo-continents Laurentia, Baltica and Siberia. Geol. Soc. London, Memoirs 32, pp. 507–520. Glebovsky, V.Yu., Astafurova, E.G., Chernykh, A.A., Korneva, M.A., Kaminsky, V.D., Poselov, V.A., 2013. Thickness of the Earth’s crust in the deep Arctic Ocean: Results of a 3D gravity modeling. Russian Geology and Geophysics (Geologiya i Geofizika) 54 (3), 247–262 (327–344). Golonka, J., Bocharova, N.Y., Ford, D., Edrich, M.E., Bednarczyk, J., Wildharber, J., 2003. Paleogeographic reconstructions and basins development of the Arctic. Mar. Pet. Geol. 20 (3–4), 211–248, doi:10.1016/ S0264-8172(03)00043-6. Golonka, J., Ford, D., 2000. Pangean (Late Carboniferous–Middle Jurassic) paleoenvironment and lithofacies. Palaeogeogr. Palaeoclimatol. Palaeoecol. 161 (1–2), 1–34. Gramberg, I.S. (Ed.), 1988. Barents Shelf Plate [in Russian]. Nedra, Leningrad. Grantz, A., Clark, D.L., Phillips, R.L., Srivastava, S.P., Blome, C.D., Gray, L.B., Haga, H., Mamet, B.L., McIntyre, D.J., McNeil, D.H., Mickey, M.B., Mullen, M.W., Murchey, B.I., Ross, C.A., Stevens, C.H., Silberling, N.J., Wall, J.H., Willard, D.A., 1998. Phanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada basin, and the geometry and timing of rifting in the Amerasia basin, Arctic Ocean. Geol. Soc. Am. Bull. 110 (6), 801–820. 856 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 Grantz, A., Pease, V.L., Willard, D.A., Phillips, R.L., Clark, D.L., 2001. Neogene paleoceanography of Lomonosov Ridge and a tie to the Barents shelf Bedrock. Geol. Soc. Am. Bull. 113, 1272–1281. Grantz, A., Scott, R.A., Drachev, S.S., Moore, T.E., 2009. Map showing the sedimentary successions of the region (58º–64º to 90º N) that be prospective for hydrocarbons. GIS-UDRIL,s Open Files. Imaev, V.S., Imaeva, L.S., Koz’min, B.M., Mackey, K., Fujita, K., 1998. Seismic and tectonic processes on the boundary of lithospheric plates of North East Asia and Alaska. Tikhookeanskaya Geologiya 17 (2), 3–17. Jackson, G.P., Johnson, G.L., 1984. Structure and history of the Amerasian Basin, in: Geology of the Arctic (Proc. 27 I.G.C.; Coll. 04). Moscow, pp. 105–118. Jakovlev, A.V., Bushenkova, N.A., Koulakov, I.Yu., Dobretsov, N.L., 2012. Structure of the upper mantle in the Circum-Arctic region from regional seismic tomography. Russian Geology and Geophysics (Geologiya i Geofizika) 53 (10), 963–971 (1261–1272). Kaban’kov, V.Ya., Rogozov Yu.G., Makar’ev A.A., 1982. Stratigraphy of Upper Proterozoic deposits of Bolshevik Island (Severnaya Zemlya archipelago), in: Geology of the Severnaya Zemlya Archipelago [in Russian]. Sevmorgeo, Leningrad, pp. 5–22. Khain, V.E., 1979. Regional Geotectonics: Out-Alpine Asia and Australia [in Russian]. Nedra, Moscow. Khain, V.E., Gusev, G.S., Khain, E.V., Vernikovsky, V.A., Volobuyev, M.I., 1997. Circum-Siberian Neoproterozoic Ophiolite Belt. Ofioliti 22 (2), 195–200. Khain, V.E., Polyakova, I.D., Filatova, N.I., 2009. Tectonics and petroleum potential of the East Arctic province. Russian Geology and Geophysics (Geologiya i Geofizika) 50 (4), 334–345 (443–460). Khain, V.E., Filatova, N.I., Polyakova, I.D., Chekhovich, V.D. (Eds.), 2011. Tectonic Map of the Eastern Arctic Region. Scale 1:2,500,000 [in Russian]. IPGG SB RAS, Novosibirsk. Khanchuk, A.I. (Ed.), 2006. Geodynamics, Magmatism and Metallogeny of the East of Russia [in Russian], in 2 vols. Dal’nauka, Vladivostok. Klemperer, S.L., Miller, E.L., Scholl, D.W., 2002. Crustal structure of the Bering and Chukchi shelves: deep seismic reflection profiles across the North American continent between Alaska and Russia, in: Miller, E.L., Grantz, A., Klemperer, S.L. (Eds.), Tectonic Evolution of the Bering Shelf–Chukchi Sea–Arctic Margin and Adjacent Landmasses. Geol. Soc. Amer., Spec. Pap. 360, Boulder, USA, pp. 1–24. Korago, E.A., Timofeeva, T.N., 2005. Magmatism of Novaya Zemlya (in the Context of the Geologic History of the Barents–North Kara Region) (Trans. VNIIOkeangeologiya, Vol. 209) [in Russian]. VNIIOkeangeologiya, St. Petersburg. Korago, E.A., Kovaleva, G.N., Ilyin, V.F., Pavlov, L.G., 1992. Tectonics and Metallogeny of the Early Cimmeride of Novaya Zemlya [in Russian]. Nedra, St. Petersburg. Korago, E.A., Evdokimov, A.N., Stolbov, N.M., 2010. Late Mesozoic and Cenozoic Basic Magmatism of the Northwest of Eurasia’s Continental Margin (Trans. VNIIOkeangeologiya, Vol. 215) [in Russian]. VNIIOkeangeologiya, St. Petersburg. Korobkin, V.V., Buslov, M.M., 2011. Tectonics and geodynamics of the western Central Asian Fold Belt (Kazakhstan Paleozoides). Russian Geology and Geophysics (Geologiya i Geofizika) 52 (12), 1600–1618 (2032–2055). Kos’ko, M.K., 1977. Folded basement of shelf sedimentary basins, in: Tectonics of the Arctic [in Russian]. NIIGA, Leningrad, pp. 55–85. Koulakov, I.Yu., Dobretsov, N.L., Bushenkova N.A., Jakovlev, A.V., 2011. Slab shape in subduction zones beneath the Kurile–Kamchatka and Aleutian arcs based on regional tomography results. Russian Geology and Geophysics (Geologiya i Geofizika) 52 (6), 650–667 (830–851). Koulakov, I.Yu., Gaina, C., Dobretsov, N.L., Vasilevsky, A.N., Bushenkova, N.A., 2013. Plate reconstructions in the Arctic region based on joint analysis of gravity, magnetic, and seismic anomalies. Russian Geology and Geophysics (Geologiya i Geofizika) 54 (8), 859–873 (1108–1125). Kuzmichev, A.B., 2009. Where does the South Anyui suture go in the New Siberian islands and Laptev Sea?: Implications for the Amerasia basin origin. Tectonophysics 463, 86–108. Kuzmichev, A.B., Goldyrev, A.E., 2007. Permian–Triassic trap magmatism in Bel’kov Island (New Siberian Islands). Russian Geology and Geophysics (Geologiya i Geofizika) 48 (2), 167–176 (216–228). Kuzmichev, A.B., Pease, V.L., 2007. Siberian trap magmatism on the New Siberian Islands: constraints for Arctic Mesozoic plate tectonic reconstructions. J. Geol. Soc. London, 164, 959–968. Kuznetsov, N.B., 2008. The Cambrian Pre-Uralide–Timanide orogen: structural evidence for its collisional origin. Dokl. Earth Sci. 423A (9), 1383–1387, doi: 10.1134/S1028334X08090122. Kuznetsov, N.B., Soboleva, A.A., Udoratina, O.V., Gertseva, M.V., 2005. Pre-Ordovician Granitoids of the Timan-Ural Region and Evolution of the Protouralides–Timanides [in Russian]. Geoprint, Syktyvkar. Langinen, A.E., Lebedeva-Ivanova, N.N., Gee, D.G., Zamansky, Yu.Ya., 2009. Correlations between the Lomonosov Ridge, Marvin Spur and adjacent basins of the Arctic Ocean based on seismic data. Tectonophysics 472, 309–322. Laverov, N.P., Lobkovsky, L.I., Kononov, M.V., Dobretsov, N.L., Vernikovsky, V.A., Sokolov, S.D., Shipilov, E.V., 2013. A geodynamic model of the evolution of the Arctic basin and adjacent territories in the Mesozoic and Cenozoic and the outer limit of the Russian Continental Shelf. Geotectonics (Geotektonika) 47 (1), 1–30 (3–35), doi: 10.1134/S0016852 113010044. Lawver, L.A., Ganagan, L.M., Norton, I., 2011. Paleogeographic and tectonic evolution of the Arctic region during the Paleozoic, in: Spencer, A.M., Embry, A.F., Gautier, D.L., Stoupakova, A.V., Sørensen, K. (Eds.), Arctic Petroleum Geology. Geol. Soc. London Memoirs 35, pp. 61–77. Lebedeva-Ivanova, N.N., Zamansky, Y.Y., Langinen, A.E., Sorokin, M.Y., 2006. Seismic profiling across the Mendeleev Ridge at 82° N: Evidence of continental crust. Geophys. J. Int. 165, 527–544. Li, Z.X., Bogdanova, S.V., Collins, A.S., Davidson, A., Waele, B.De., Ernst, R.E., Fitzsimons, I.C.W., Fuck, R.A., Gladkochub, D.P., Jacobs, J., Karlstrom, K.E., Lul, S., Natapov, L.M., Pease, V., Pisarevsky, S.A., Thrane, K., Vernikovsky, V., 2008. Assembly, configuration, and break-up history of Rodinia: A synthesis. Precambrian Res. 160, 179–210. Linnemann, U., Pereira, F., Jeffries, T.E., Drost, K., Gerdes, A., 2008. The Cadomian Orogeny and the opening of the Rheic Ocean: The diacrony of geotectonic processes constrained by LA-ICP-MS U–Pb zircon dating (Ossa-Morena and Saxo-Thuringian Zones, Iberian and Bohemian Massifs). Tectonophysics 461, 21–43. Lobkovsky, L.I., Verzhbitsky, V.E., Kononov, M.V., Shreider, A.A., Garagash, I.A., Sokolov, S.D., Tuchkova, M.I., Kotelkin, V.D., Vernikovsky, V.A., 2011. A geodynamic model for the evolution of the Arctic region in the Late Mesozoic-Cenozoic and the issues of the outer boundary of Russia’s continental shelf. Arktika. Ecologiya i Ekonomika 1 (1), 104–115. Lorenz, H., Männik, P., Gee, D., Proskurnin, V., 2008. Geology of the Severnaya Zemlya Archipelago and the North Kara Terrane in the Russian high Arctic. Int. J. Earth Sci. (Geol. Rundsch.) 97 (3), 519–547, doi: 10.1007/s00531-007-0182-2. McElhinny, M.W., MacFadden, P.L., 2000. Paleomagnetism: Continents and Oceans. Academic Press, San Diego. Metelkin, D.V., 2013. Kinematic reconstruction of the Early Caledonian accretion in the southwest of the Siberian paleocontinent based on paleomagnetic results. Russian Geology and Geophysics (Geologiya i Geofizika) 54 (4), 381–398 (500–522). Metelkin, D.V., Kazansky, A.Yu., Vernikovsky, V.A., Gee D., Torsvik T., 2000. First paleomagnetic data on the Early Paleozoic rocks from the Severnaya Zemlya archipelago and their geodynamic interpretation. Geologiya i Geofizika (Russian Geology and Geophysics) 41 (12), 1816–1820 (1767–1772). Metelkin, D.V., Vernikovsky, V.A., Kazansky, A.Yu., Bogolepova, O.K., Gubanov, A.P., 2005. Paleozoic history of the Kara microcontinent and its relation to Siberia and Baltica: paleomagnetism, paleogeography and tectonics. Tectonophysics 398, 225–243. Metelkin, D.V., Vernikovsky, V.A., Kazansky, A.Yu., Wingate, M.T.D., 2010. Late Mesozoic tectonics of Central Asia based on paleomagnetic evidence. Gondwana Res. 18 (2–3), 400–419. Metelkin, D.V., Vernikovsky, V.A., Kazansky, A.Yu., 2012. Tectonic evolution of the Siberian paleocontinent from the Neoproterozoic to the Late V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 Mesozoic: paleomagnetic record and reconstructions. Russian Geology and Geophysics (Geologiya i Geofizika) 53 (7), 675–688 (883–899). Miller, E.L., Verzhbitsky, V.E., 2009. Structural studies near Pevek, Russia: Implications for formation of the East Siberian Shelf and Makarov Basin of the Arctic Ocean, in: Stone, D.B., Fujita, K., Layer, P.W., Miller, E.L., Prokopiev, A.V., Toro, J., Geology, Geophysics and Tectonics of Northeastern Russia: A Tribute to Leonid Parfenov. EGU Stephan Mueller Publication Series, Vol. 4, pp. 223–241. Murphy, J.B., Gutierrez-Alonso, G., Nance, R.D., Fernandez-Suarez, J., Keppie, J.D., Quesada, C., Strachan, R.A., Dostal, J., 2006. Origin of the Rheic Ocean: Rifting along a Neoproterozoic suture? Geology 34, 325–328. Natal’in, B.A., Amato, J.M., Toro, J., Wright, J.E., 1999. Paleozoic rocks of northern Chukotka Peninsula, Russian Far East: Implications for the tectonics of the Arctic region. Tectonics 18, 977–1003. Nikishin, A.M., Ziegler, P.A., Stephenson, R.A., Cloetingh, S.A.P.L., Furne, A.V., Fokin, P.A., Ershov, A.V., Bolotov, S.N., Korotaev, M.V., Alekseev, A.S., Gorbachev, V.I., Shipilov, E.V., Lankreijer, A., Bembinova, E.Yu., Shalimov, I.V., 1996. Late Precambrian to Triassic history of the East European Craton: dynamics of sedimentary basin evolution. Tectonophysics 268, 23–63. Oxman, V.S., 2003. Tectonic evolution of the Mesozoic Verkhoyansk-Kolyma belt (NE Asia). Tectonophysics 365, 45–76. Pease, V., Gee, D.G., Vernikovsky, V., Vernikovskaya, A.E., Kireev, S., 2001. Geochronological evidence for Late-Grenvillian magmatic and metamorphic events in Central Taimyr, Northern Siberia. Terra Nova 13, 270–280. Pechersky, D.M., Didenko, A.N., 1995. The Paleo-Asian Ocean: Petromagnetic and Paleomagnetic Information on its Lithosphere [in Russian]. JIPE RAS, Moscow. Pisarevsky, S.A., Natapov, L.M., Donskaya, T.V., Gladkochub, D.P., Vernikovsky, V.A., 2008. Proterozoic Siberia: a promontory of Rodinia. Precambrian Res. 160, 66–76. Pogrebitsky, Yu.E., 1971. Paleotectonic Analysis of the Taimyr Fold System [in Russian]. Nedra, Leningrad. Poselov, V.A., Avetisov, G.P., Butsenko, V.V., Zholondz, S.M., Kaminsky, V.D., Pavlov S.P., 2012. The Lomonosov Ridge as a natural extension of the Eurasian continental margin into the Arctic Basin. Russian Geology and Geophysics (Geologiya i Geofizika) 53, 1276–1290 (1662–1680). Proskurnin, V.F., 1995. A new volcanic-plutonic association in Severnaya Zemlya and particularities of its ore potential, in: Subsoil of Taimyr [in Russian]. Norilsk, Issue 1, pp. 93–100. Puchkov, V.N., 2000. Paleogeodynamics of the Southern and Middle Ural [in Russian]. Dauriya, Ufa. Puchkov, V.N., 2003. Uralides and Timanides: their structural relationship and position in the geologic history of the Ural-Mongolian fold belt. Geologiya i Geofizika (Russian Geology and Geophysics) 44 (1–2), 28–39 (27–38). Rekant, P.V., Gusev, E.A., 2012. Seismic geologic structure model for the sedimentary cover of the Laptev Sea part of the Lomonosov Ridge and adjacent parts of the Amundsen Plain and Podvodnikov Basin. Russian Geology and Geophysics (Geologiya i Geofizika) 53 (11), 1150–1162 (1497–1512). Saraev, S.V., Baturina, T.P., Bakharev, N.K., Izokh, N.G., Sennikov, N.V., 2012. Middle–Late Devonian island-arc volcanosedimentary complexes in northwestern Rudny Altai. Russian Geology and Geophysics (Geologiya i Geofizika) 53 (10), 982–996 (1285–1303). Scotese, C.R., 1997. Paleogeographic Atlas / PALEOMAP Progress Report 90-0497, Department of Geology, University of Texas at Arlington, Arlington, TX. Shatsky, N.S., 1963–1965. Selected Works. Vols. I–IV [in Russian]. Nauka, Moscow. Shipilov, E.V., 2008. Generations of spreading basins and stages of breakdown of Wegener’s Pangea in the geodynamic evolution of the Arctic Ocean. Geotectonics (Geotektonika) 42 (2), 105–124 (32–54), doi: 10.1134/ S0016852108020027. Shipilov, E.V., Senin, B.V., 1988. Deep structure of the Barents Sea floor. Geotectonika 76, 96–100. 857 Shipilov, E.V., Vernikovsky, V.A., 2010. The Svalbard–Kara plates junction: structure and geodynamic history. Russian Geology and Geophysics (Geologiya i Geofizika) 51 (1), 58–71 (75–92). Smethurst, M.A., Khramov, A.N., Torsvik, T.H., 1998. The Neoproterozoic and Paleozoic paleomagnetic data for the Siberian Platform: from Rodinia to Pangaea. Earth Sci. Rev. 43, 1–24. Sokolov, S.D., Bondarenko, G.E., Morozov, O.L., Ganelin, A.V., Podgorny I.I., 2001. Nappe-type tectonics of the South-Anyui suture in the Western Chukot Peninsula. Dokl. Earth Sci. 376 (1), 7–11. Sokolov, S.D., Bondarenko, G.Ye., Layer, P.W., Kravchenko-Berezhnoy, I.R., 2009. South Anyui suture: tectono-stratigraphy, deformations, and principal tectonic events, in: Stone, D.B., Fujita, K., Layer, P.W., Miller, E.L., Prokopiev, A.V., Toro, J. (Eds.), Geology, Geophysics and Tectonics of Northeastern Russia: A Tribute to Leonid Parfenov. EGU Stephan Mueller Publication Series, Vol. 4, pp. 201–221. Sokolov, S.D., Tuchkova, M.I., Bondarenko, G.E., 2010. A tectonic model of the South Anyui suture and its role in the formation in the structures of the East Arctic, in: Structure and Evolution History of the Lithosphere [in Russian]. Paulsen, Moscow, pp. 204–227. Stein, S., Sella, F., 2002. Plate boundary zones: concept and approaches, in: S. Stein, S., Freymueller, J. (Eds.), Plate Boundary Zones. Geodynamics Series 30. AGU, Washington, D.C., pp. 1–26. Torsvik, T.H., Cocks, L.R.M., 2005. Norway in space and time: A Centennial cavalcade. Norwegian J. Geol. 85, 73–86. Torsvik, T.H., Van der Voo, R., 2002. Refining Gondwana and Pangea paleogeography: estimates of Phanerozoic non-dipole (octupole) fields. Geophys. J. Int. 151 (3), 771–794. Torsvik, T.H., Smethurst, M.A., Meert, J.G., Van der Voo, R., McKerrow, W.S., Brasier, M.D., Sturt, B.A., Walderhaug, H.J., 1996. Continental break-up and collision in the Neoproterozoic—a tale of Baltica and Laurentia. Earth Sci. Rev. 40, 229–258. Uflyand, A.K., Natapov, L.M., Lopatin, V.M., Chernov, D.V., 1991. On the tectonic nature of Taimyr. Geotectonika 25 (6), 76–93. Verba, M.L., Roslov, Yu.V., Sakulina, T.S., 2005. Novaya Zemlya in the structure of the Ob’-Barents sedimentary megabasin from results on the supporting profile 2-AP. Razvedka i Okhrana Nedr, No. 1, 6–9. Vernikovsky, V.A., 1996. Geodynamic Evolution of Taimyr Folded Area [in Russian]. Publishing House SB RAS, SPC UIGGM, Novosibirsk. Vernikovsky, V.A., Vernikovskaya, A.E., 2001. Central Taimyr accretionary belt (Arctic Asia): Meso-Neoproterozoic tectonic evolution and Rodinia breakup. Precambrian Res. 110, 127–141. Vernikovsky, V.A., Neimark, L.A., Ponomarchuk, V.A., Vernikovskaya, A.E., 1995. Geochemistry and age of collisional granitoides and metamorphites of the Kata microcontinent (Northern Taimyr). Geologiya i Geofizika (Russian Geology and Geophysics) 36 (12), 50–64 (46–60). Vernikovsky, V.A., Vernikovskaya, A.E., Chernykh, A.I., Mel’gunov M.S., 1996. Petrology and geochemistry of Taimyr Riphean ophiolites. Geologiya i Geofizika (Russian Geology and Geophysics) 37 (1), 113–129 (103–121). Vernikovsky, V.A., Pease, V.L., Vernikovskaya, A.E., Romanov, A.P., Gee, D.J., Travin, A.V., 2001. Early Triassic A-granites in the Taimyr region as a result of a North Asian superplume. Dokl. Earth Sci. 380, 758–763. Vernikovsky, V.A., Pease V., Vernikovskaya, A.E., Romanov, A., Gee, D.G., Travin, A., 2003. First report of early Triassic A-type granite and syenite intrusions from Taimyr: product of the northern Eurasian superplume? Lithos 66 (1–2), 23–36. Vernikovsky, V.A., Dobretsov, N.L., Kaminsky, V.D., Lobkovsky, L.I., Shipilov, E.V., 2010. Geodynamics of the Central and Eastern Arctic, in: Proceedings of the Meeting on the Coordination of the RAS on the Study of the Arctic and the Antarctic [in Russian]. Arkhangelsk–Yekaterinburg, pp. 41–58. Vernikovsky, V.A., Metelkin, D.V., Vernikovskaya, A.E., Sal’nikova, E.B., Kovach, V.P., Kotov, A.B., 2011. The oldest island arc complex of Taimyr: Concerning the issue of the Central-Taimyr accretionary belt formation and paleogeodynamic reconstructions in the arctic. Dokl. Earth Sci. 436 (2), 186–192, doi: 10.1134/S1028334X1102019X. Vernikovsky, V.A., Metelkin, D.V., Tolmacheva, T.Yu., Malyshev, N.A., Petrov, O.V., Sobolev, N.N., Matushkin, N.Yu., 2013. Concerning the 858 V.A. Vernikovsky et al. / Russian Geology and Geophysics 54 (2013) 838–858 issue of paleotectonic reconstructions in the Arctic and of the tectonic unity of the New Siberian Islands terrane: new paleomagnetic and paleontological data. Dokl. Earth Sci. 451 (4). Wilhem, C., Windley, B.F., Stampfli, G.M., 2012. The Altaids of Central Asia: A tectonic and evolutionary innovative review. Earth Sci. Rev. 113, 303–341. Windley, B.F., Alexeiev, D., Xiao, W.J., Kroner, A., Badarch, G., 2007. Tectonic models for accretion of the Central Asian orogenic belt. J. Geol. Soc. London 164, 31–47. Wingate, M.T.D., Giddings, J.W., 2000. Age and paleomagnetism of the Mundine Well dyke swarm, Western Australia implications for an Australia–Laurentia connection at 755 Ma. Precambrian Res. 100, 335– 357. Zonenshain, L.P., Natapov, L.M., 1987. Tectonic history of the Arctic, in: Current Problems of the Tectonics of Oceans and Continents [in Russian]. Nauka, Moscow, pp. 31–57. Zonenshain, L.P., Kuzmin, M.I., Natapov, L.M., 1990. Plate Tectonics of the USSR [in Russian], in 2 vols. Nedra, Moscow, Vol. 1.