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Abstract: The overall jump in global demand for gas, and especially oil, gives rise to particular concern regarding mankind’s energy future. In the middle and late 21st century, the crucial role in securing oil and gas supply of mankind will be played by sedimentary basins in the Arctic Ocean deep-water area, including those of the continental shelf in Russia’s Arctic seas. There is a 0.90 probability that the initial in-place resources of hydrocarbons in the Arctic Ocean will be greater than 90 Btoe. The estimates predict the rise of oil and gas industries on the Arctic shelves in the near future. [Copyright &y& Elsevier]

Abstract High Arctic new seismic data, collected by Russian Federation from 2011 to 2014, and additional geological and geophysical information, are used to interpret the basement and sedimentary structure of central and eastern Eurasia Basin, the Gakkel Ridge, and their transition into the Laptev Sea. We find that significant changes in basement topography occur in Nansen Basin at C20 (43.43 Ma) and in the Amundsen basins at C21 (45.7 Ma), and in both basins at C13 (33 Ma). A long seismic profile, that documents for the first time the structure of conjugate flanks and their margins in the central-eastern Eurasia Basin, confirms that oceanic accretion was asymmetric, with 10% less crust developed in the Amundsen Basin since continental break-up. In the eastern Amundsen Basin, we observe mid-ocean ridge uplift since C13 (33 Ma). We identify four distinct sedimentary packages in the Eurasia Basin: Early to Mid Eocene (c. 56 to 45.7 Ma), Mid Eocene to Early Oligocene (45.7 to 33.2 Ma), Early Oligocene to Early Miocene (33.2 to 19.7) and Early Miocene to Present (19.7 to 0 Ma); they are linked to the oceanic lithosphere age determined from magnetic data. The deepest part of the Gakkel Ridge (5215 m), situated close to the easternmost part of this mid ocean ridge, is imaged for the first time by seismic data that reveals volcanic constructions within the older axial ridges and on the flanks. Gakkel Ridge's asymmetric flanks with shallow, regularly-spaced, and rugged structure, typical to ultra-slow spreading ridges, imply periodicity of tectonic phases. The Khatanga-Lomonosov Fault between Lomonosov Ridge and the Laptev Sea region, is identified on few seismic profiles; kinematic models predict that it may have been active only for a maximum of 10 myr after continental break-up. Graphical abstract Image 1 Highlights • Asymmetric spreading in the eastern Eurasia Basin • East Gakkel Ridge tectono-magmatic segmentation • Strike-slip and transtension north of Laptev Sea since Eocene [ABSTRACT FROM AUTHOR]

Combined (U-Th)/He and U-Pb detrital zircon geochronological data are reported from Ordovician to Devonian strata of the Severnaya Zemlya archipelago to address the paleogeography of the Kara Terrane in the Russian High Arctic. (U-Th)/He ages from all six samples analyzed were not reset after sediment deposition, indicating that detrital zircons carry information on the exhumation history in the source region of the clastic material. In Ordovician-Silurian strata, (U-Th)/He ages range from 583.8 ± 46.7 to 429.0 ± 34.3 Ma. These ages nicely coincide with significant regional exhumation during the Caledonian and Timanian orogenies. In addition, combined U-Pb and (U-Th)/He dating show that within the source region, zircons that were crystalized during the Timanian Orogeny (U-Pb ages 680–560 Ma) were likely exhumed during younger Caledonian events ((U-Th)/He ages of 455–495 Ma), suggesting potential overlap of these orogens within the source region. In Devonian strata, detrital zircon (U-Th)/He ages range from 517.2 ± 41.38 to 332.9 ± 26.6 Ma, with a peak age of ca. 375 Ma. This 375 Ma event may be correlated with either the Ellesmerian Orogeny or the terminal Solundian/Svalbardian stages of the Caledonian Orogeny. [ABSTRACT FROM AUTHOR]