MODEL OF THE ARLIS SPUR SPALL FROM THE LOMONOSOV RIDGE IN THE ARCTIC OCEAN

The work presents a reconstruction of the bottom paleo-relief in the Arctic polar region, from the Lomonosov Ridge to the Mendeleev Ridge. The Makarov Basin is between these ridges. At that, it is separated from the adjacent Podvodnikov Basin by a low, up to 2.5 km deep, threshold, which is called the Arlis Spur. The spur adjoins, or perhaps even forms a part of the Geophysicists Spur, as indicated in the national UN application for the delimitation of the shelf, or the Oden Spur. The origin of the central arctic structures of the bottom topography is of a key role in the problem of elucidating the nature of the Arctic Ocean polar region as a whole. In this regard, it is important to reconstruct the features of the Barents-Kara paleo-periphery of the continent, the fragments of which include the Arlis Spur and adjacent bottom areas. Deep-water drilling and specific geophysical work (seismic, aeromagnetic, etc.) aimed at restoring geochronology and geodynamics of the seabed in the objects’ area has not yet been carried out in the region. Restoration of the bottom paleo-relief was carried out using a computer technique for the best alignment of isolines, in particular isobaths, which, as established or is supposed to, once formed a single contour. In the course of work, the isobath sections in the range of 2.1–2.9 km, which correspond to the steepest part of the slope and, according to the nature of the sedimentary layer, having low thickness of sediments, turned to be the most suitable for paleogeodynamic analysis. The result of the reconstruction is the restoration of the axes of the abruption zones of the peripheral regions of the Lomonosov and Mendeleev Ridges in the Arlis Spur area. An important circumstance of the reconstruction is the difference between joined isobaths in depth up to 0.6 km. The latter circumstance most likely reflects the fact of multi-scale slipping along the fault plane and, thus, different-scale burial in the process of splitting off the peripheral regions of the continental crust from the main body of the Lomonosov Ridge. The main result of this work is to obtain an independent confirmation of the connection between the Arlis Spur and the periphery fragment of the Mendeleev Ridge with the Lomonosov Ridge and a conclusion about their continental nature. The work results are important for justifying the location of the outer boundary of the Russian continental shelf.

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