The role of rifting in the formation of the recent structure of the Mongolia-Okhotsk orogen is extremely high, but it is still underestimated with regard to flanks of the Dzhagda segment of this orogen. Current researches refer to a combination of physical and chemical processes in the depth of the lithosphere, as well as interactions between the Izanagi, Eurasian and Pacific plates as explanations of repeated rifting events in East Asia. Upwelling of the asthenosphere due to significant differences in the lithosphere thickness (150-200 km under cratons, and only 100 km under orogenic belts) was viewed as a cause of rifting. It was assumed that rifting was controlled by mantle plumes, volcanism and heat regime. Structures bordering the Mongolia-Okhotsk orogen from north and south were considered as superimposed or marginal troughs. Recent studies have revealed numerous riftogenic Late Mesozoic structures in the Central Asian orogenic belt, which resulted from the collision of the Siberian and North Chinese cratons. New geological survey and geochemical data on volcanites confirmed the riftogenic origin of the Zeya-Uda (or Uda) and Nora-Selemdzha troughs bordering the Mongolia-Okhotsk orogen from north and south, respectively ( Fig. 1, and 2). Geology and geophysics of those troughs has been described. It is noted that riftogenic volcanites formed later in the east than those in the west. The Late Mesozoic rifting is widely manifested in North Eastern Asia across the area exceeding two million square kilometers, from Lake Baikal to the Sikhote-Alin region (west to east) and from the Southern Yakutia basins to North China (north to south). It is evidenced by intra-continental rifts of various trends, volcanic provinces and extension structures along large strike-slip faults [Ren et al., 2002]. The Uda and Nora-Selemdzha marginal troughs located along the Dzhagda segment of the Mongolia-Okhotsk orogen give evidence that compression was replaced by extension in the study area. Rifting structures may be due to physical and chemical processes, the development of plumes [Yarmolyuk et al., 2000], as well as the interaction between the Pacific and Eurasian lithospheric plates. Volcanic activity took place earlier in the west and then propagated to the east due to the shifting of the subduction zone in this direction. This paper analyzes regional and global geological events on the basis of new drilling data and the geochronological dating of volcanites. It describes the Late Mesozoic stage of rifting at the flanks of the Dzhagda segment of the Mongolia-Okhotsk collisional orogen. P a l e o g e o d y n a m i c s RESEARCH ARTICLEДля цитирования: Кириллова Г.Л. Позднемезозойский рифтогенез на флангах Джагдинского звена Монголо-Охотского коллизионного орогена: глобальные и региональные аспекты // Геодинамика и тектонофизика.

We present a revised global plate motion model with continuously closing plate boundaries ranging from the Triassic at 230 Ma to the present day, assess differences among alternative absolute plate motion models, and review global tectonic events. Relatively high mean absolute plate motion rates of approximately 9–10 cm yr−1 between 140 and 120 Ma may be related to transient plate motion accelerations driven by the successive emplacement of a sequence of large igneous provinces during that time. An event at ∼100 Ma is most clearly expressed in the Indian Ocean and may reflect the initiation of Andean-style subduction along southern continental Eurasia, whereas an acceleration at ∼80 Ma of mean rates from 6 to 8 cm yr−1 reflects the initial northward acceleration of India and simultaneous speedups of plates in the Pacific. An event at ∼50 Ma expressed in relative, and some absolute, plate motion changes around the globe and in a reduction of global mean plate speeds from about 6 to 4–5 cm yr−1 indicates that an increase in collisional forces (such as the India–Eurasia collision) and ridge subduction events in the Pacific (such as the Izanagi–Pacific Ridge) play a significant role in modulating plate velocities.

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Global deep‐time plate motion models have traditionally followed a classical rigid plate approach, even though plate deformation is known to be significant. Here we present a global Mesozoic–Cenozoic deforming plate motion model that captures the progressive extension of all continental margins since the initiation of rifting within Pangea at ~240 Ma. The model also includes major failed continental rifts and compressional deformation along collision zones. The outlines and timing of regional deformation episodes are reconstructed from a wealth of published regional tectonic models and associated geological and geophysical data. We reconstruct absolute plate motions in a mantle reference frame with a joint global inversion using hot spot tracks for the last 80 million years and minimizing global trench migration velocities and net lithospheric rotation. In our optimized model, net rotation is consistently below 0.2°/Myr, and trench migration scatter is substantially reduced. Distributed plate deformation reaches a Mesozoic peak of 30 × 106 km2 in the Late Jurassic (~160–155 Ma), driven by a vast network of rift systems. After a mid‐Cretaceous drop in deformation, it reaches a high of 48 x 106 km2 in the Late Eocene (~35 Ma), driven by the progressive growth of plate collisions and the formation of new rift systems. About a third of the continental crustal area has been deformed since 240 Ma, partitioned roughly into 65% extension and 35% compression. This community plate model provides a framework for building detailed regional deforming plate networks and form a constraint for models of basin evolution and the plate‐mantle system.

GPlates is an open‐source, cross‐platform plate tectonic geographic information system, enabling the interactive manipulation of plate‐tectonic reconstructions and the visualization of geodata through geological time. GPlates allows the building of topological plate models representing the mosaic of evolving plate boundary networks through time, useful for computing plate velocity fields as surface boundary conditions for mantle convection models and for investigating physical and chemical exchanges of material between the surface and the deep Earth along tectonic plate boundaries. The ability of GPlates to visualize subsurface 3‐D scalar fields together with traditional geological surface data enables researchers to analyze their relationships through geological time in a common plate tectonic reference frame. To achieve this, a hierarchical cube map framework is used for rendering reconstructed surface raster data to support the rendering of subsurface 3‐D scalar fields using graphics‐hardware‐accelerated ray‐tracing techniques. GPlates enables the construction of plate deformation zones—regions combining extension, compression, and shearing that accommodate the relative motion between rigid blocks. Users can explore how strain rates, stretching/shortening factors, and crustal thickness evolve through space and time and interactively update the kinematics associated with deformation. Where data sets described by geometries (points, lines, or polygons) fall within deformation regions, the deformation can be applied to these geometries. Together, these tools allow users to build virtual Earth models that quantitatively describe continental assembly, fragmentation and dispersal and are interoperable with many other mapping and modeling tools, enabling applications in tectonics, geodynamics, basin evolution, orogenesis, deep Earth resource exploration, paleobiology, paleoceanography, and paleoclimate.

The breakup of Pangea in the Jurassic saw the opening of major ocean basins at the expense of older Tethyan and Pacific oceanic plates. Although the Tethyan seafloor spreading history has been lost to subduction, proxy indicators from multiple generations of Tethyan ribbon terranes, as well as the active margin geological histories of volcanism and ophiolite obduction events can be used to reconstruct these ancient oceanic plates. The plate reconstructions presented in this study reconcile observations from ocean basins and the onshore geological record to provide a regional synthesis, embedded in a global plate motion model, of the IndiaEurasia convergence history, the accretionary growth of Southeast Asia and the Tethyan-Pacific tectonic link through the New Guinea margin. The global plate motion model presented in this study captures the timedependent evolution of plates and their tectonic boundaries since 160 Ma, which are assimilated as surface boundary conditions for numerical experiments of mantle convection. We evaluate subducted slab locations and geometries predicted by forward mantle flow models against P-and S-wave seismic tomography models. This approach harnesses modern plate reconstruction techniques, mantle convection models with imposed one-sided subduction, and constraints from the surface geology to address a number of unresolved Tethyan geodynamic controversies. Our synthesis reveals that north-dipping subduction beneath Eurasia in the latest Jurassic consumed the Meso-Tethys, and suggests that northward slab pull opened the younger Neo-Tethyan ocean basin from ~ 155 Ma. We model the rifting of ' Argoland', representing the East Java and West Sulawesi continental fragments, as a northward transfer of continental terranes in the latest Jurassic from the northwest Australian shelf -likely colliding first with parts of the Woyla intra-oceanic arc in the mid-Cretaceous, and accreting to the Borneo (Sundaland) core by ~ 80 Ma. The Neo-Tethyan ridge was likely consumed along an intra-oceanic subduction zone south of Eurasia from ~ 105 Ma, leading to a major change in the motion of the Indian Plate by ~ 100 Ma, as observed in the Wharton Basin fracture zone bends. We investigate the geodynamic consequences of long-lived intra-oceanic subduction within the Neo-Tethys, requiring a twostage India-Eurasia collision involving first contact between Greater India and the Kohistan-Ladakh Arc sometime between ~ 60 and 50 Ma, followed by continent-continent collision from ~ 47 Ma. Our models suggest that the Sunda slab kink beneath northwest Sumatra in the mantle transition zone results from the rotation and extrusion of Indochina from ~ 30 Ma. Our results are also the first to reproduce the enigmatic Proto South China Sea slab beneath northern Borneo, as well as the Tethyan/Woyla slab that is predicted at mid-mantle depths south of Sumatra. Further east, our revised reconstructions of the New Guinea margin, notably the evolution of the Sepik composite terrane and the Maramuni subduction zone, produce...

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